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Delta/Lambda Chirality: From Enantiomers to Diastereomers in Heterometallic Complexes with Chelating Ligands
Get PDFThe Δ/Λ chirality observed in octahedral molecules with chelating ligands represents the major group of “chiral-at-metal” complexes. Upon shifting from mononuclear to polynuclear systems with multiple (≥2) chiral centers, not only enantiomers but also diastereomers should be considered. We present the first, to the best of our knowledge, diastereomeric pairs Δ,Δ,Δ/Λ,Λ,Λ (1) and Δ,Δ,Λ/Λ,Λ,Δ (2) of the pentanuclear assembly [MnII(ptac)3–Na-CoIII(acac)3–Na-MnII(ptac)3] (ptac = 1,1,1-trifluoro-5,5-dimethyl-2,4-hexanedionate; acac = acetylacetonate). Diastereomers 1 and 2 were isolated in pure form and found to exhibit distinctly different structural characteristics. Importantly, for compounds that are applied as single-source precursors for the quaternary oxide cathode material P2–Na0.67Mn0.67Co0.33O2, the diastereomers revealed different thermal behaviors in terms of volatility and thermal stability. Unambiguous assignment of the Mn and Co positions in both diastereomers has been confirmed by the synchrotron X-ray resonant diffraction technique. Oxidation states of metal ions have been verified by the synchrotron X-ray fluorescence spectroscopy. The diastereomerization between 1 and 2 is not taking place in the solid state (crystal-to-crystal), as well as in the gas phase. The transformation between two diastereomers was observed in the solutions of noncoordinating solvents and was related to the polarities of the solvents and diastereomeric molecules
Practicing U.S. Environmentalism From the Isolation of One’s Own Home: Examining the Potential Emotional Consequences of Green Consumerism
No full textThis project examines how green consumerism—the purchase and use of products perceived as less harmful to the environment—could lead to unintended harmful emotional consequences. To illustrate this, it introduces the concept of eco-entrapped individuals: a hypothetical group of people with socioeconomic privilege who likely internalize climate change as a personal burden and rigidly rely on green consumerism to provide emotional relief. Rather than green consumerism helping to alleviate emotions like anxiety, shame, guilt, and doubt, I argue that it may intensify them, potentially exacerbated by moral rumination, social withdrawal, and social isolation. To cope with these intensifying emotions, eco-entrapped individuals may continue to rigidly engage in green consumerism, confined in a cycle where every decision could feel inadequate to their high environmental standards and likely cannot fully provide emotional relief. This project hypothesizes how certain mutually reinforcing factors—shown in a diagram I created—can accelerate this cycle, amplifying the perceived individual burden of addressing climate change. I examine how the U.S. residential landscape—often characterized by restrictive single-family zoning and a restricted mix of land use types—may further accelerate these emotional consequences of eco-entrapped individuals, likely limiting consistent opportunities for positive social interactions. By synthesizing a wide range of existing interdisciplinary evidence—including but not limited to scholarship in psychology, ethics, urban studies, and sociology—I explore the potentially severe emotional toll that this group can face when being morally pushed to the edge, offering a new perspective on the unintended consequences of green consumerism. To help ease this cycle, I consider how social capital can lessen its intensity and how modifications to the existing built environment might cultivate it
Worker Citizen: Legalization and Political Relocation Among the “Walk-Route” Undocumented Chinese in the United States
No full textThis paper examines how undocumented Chinese migrants who crossed the US–Mexico border, who call themselves zouxian ke (“walk-routers”), undergo political transformation through the process of legalization. Drawing on ethnography and interviews in Chicago Chinatown, I analyze how experiences of law mediates migrants’ reinterpretation of freedom, work, and citizenship. The study proposes a model of political relocation, showing how legalization both displaces and reconfigures migrants’ pre-migration political consciousness. While universalistic critiques of authoritarianism are suspended in the exercise of self-fitting into particularistic categories of protection in the US asylum regime—a process of liberal dislocation, community interpretation of the asylum adjudication as discretionary upon economic contribution fosters neoliberal relocation, where economic frustrations from China are channeled into notions of civic worth in terms of work ethic and self-sufficiency. Through routine negotiations of statutory and discretionary criteria of legalization in daily life and workplace, migrants re-substantiate the “freedoms” they see lacking in China as the freedom to work—as symbolized by the irony of “worker citizen” —subscribing to neoliberal ideals while distancing themselves from social equity claims. By connecting migrants’ political trajectories across borders, the paper advances a transnational and sociolegal account of ideological formation that complicates binary models of incorporation and transnationalism
Equivariant Splitting of Certain Spaces CX
No full textThis dissertation generalizes the classical stable splitting theorem of Cohen, Taylor, and May to the genuine equivariant setting for a finite group . We establish that for an -free -coefficient system and a -space , the suspension -spectrum of is isomorphic to a wedge sum of the suspension -spectra of the extended powers in the equivariant stable category. The proof relies on a reduction to separated -coefficient systems and utilizes the equivariant approximation theorem of Guillou and May relating the Steiner operad to infinite loop -spaces. We construct equivariant James maps and demonstrate that specific comparison maps involving configuration -spaces induce isomorphisms on homology groups. We then discuss the implications of this splitting for computing -graded homology. Finally, we observe that the restriction to finite groups arises solely from the use of the equivariant approximation theorem. Since the main result is not inherently a theorem about infinite loop spaces, we conjecture that it generalizes to compact Lie groups via proof techniques independent of this theorem
Mirrors that Talk: The Case for a Federal Right of Publicity in an AI-Laden World
No full textThe right of publicity (ROP) is an individual’s right to control how their name, image, voice, and likeness are used in a commercial setting. With the capacities of AI systems rapidly improving, questions over protecting these important facets of identity have arisen at an alarming rate. In this paper, I analyze the ROP as a legal framework for confronting potential overreach in generative AI technologies and explain how AI is challenging the traditional American understanding of name, image, and likeness law. Using analysis of court opinions and statements from politicians on draft legislation, I recommend swift, decisive action to establish a federal ROP. I argue that maintaining the patchwork state of current AI regulations in this domain is short-sighted, and that leaving Silicon Valley companies unchecked will pose a serious threat to commercial industries and everyday activities alike
Exploring Civic Virtues among International Students
No full textCivic virtues (civility and social responsibility) support individuals’ willingness to contribute to the common good, and universities provide key opportunities for their development. Prior research suggests that short-term study abroad enhances civic virtues, but it remains unclear whether long-term immersion in a foreign country, as experienced by international students, yields similar benefits. This study examined civic virtues and related psychological constructs among 150 undergraduate students. Participants completed measures of civic engagement, civility, empathy, epistemic humility, need for cognition, wise reasoning, need for closure, and cultural competence. One-way ANOVAs revealed no group differences in civic virtues. However, international students with higher cultural competence resembled American students with study-abroad experience, scoring higher on attitudinal cultural competence than American students without such experience. International students demonstrated the strongest behavioral skills in navigating cultural differences. Across the entire sample, students with higher cultural competence showed consistently stronger civic-related characteristics. Those with greater openness to cultural differences and stronger perspective-taking abilities also demonstrated higher civility toward others, stronger civic attitudes, greater wise reasoning, and a higher need for cognition
Invisible water in subducted crust: Lawsonite velocity anomalies under mantle conditions
No full textSubduction zones transport significant amounts of water into Earth’s mantle, primarily through hydrous minerals such as lawsonite. However, the seismic detectability of lawsonite-bearing oceanic crust at mantle depths remains uncertain. To address this issue, we measured sound velocities of lawsonite up to 7.4 GPa and 600 °C. Both P- and S-wave velocities exhibited unexpected increases with temperature under high-pressure conditions. Our result suggest that hydrous oceanic crust exhibits higher seismic velocities than the surrounding mantle at depths of 150 to 250 km, resulting in high-velocity anomalies rather than the previously assumed low-velocity anomalies. Furthermore, the seismic velocity difference between hydrous and dry oceanic crust is less than 2%, making it challenging to distinguish between them using seismic velocities. This limitation may hinder the detection of the hydration state in subducted crust. In addition, lawsonite remains stable in 90% of subduction zones, and thus, such “seismically invisible water” may exist in most subducted slabs around the world.</p
Prioritizing Marginality and Resistance in Racial Identity Research
No full text Ample research shows that racial identity—how one understands and relates to their racial group—is a key developmental resource for young people, particularly Black youth and youth from racially minoritized communities in the United States. The far reach of racial identity is notable and has nurtured a robust literature focused on the strengths and resources that flourish within marginalized families and communities. Still, racial identity for youth living at the margins of society is more than an individual-level resource; it is also a collective process of resistance for liberation. Guided by the m(ai)cro framework, which locates the macrosystem as the epicenter of human development, we take this review article as an opportunity to reflect on the radical potential that resides at the edges of racial identity research. Specifically, we describe four m(ai)cro shifts that can move racial identity research beyond its current focus on ( a ) the individual (to include the sociopolitical), ( b ) discrete racial categories (to include intersectionality and multiraciality), ( c ) racial oppression (to include whiteness and privilege), and ( d ) measures that assess the amount or degree (i.e., “how much”) of racial identity constructs (to prioritize meaning-making and lived experience). Our hope is to engage a critical reflection that continues to scaffold a racial identity scholarship that is fueled by and toward collective resistance and liberation. </p
The shape of waning vaccinal immunity: Implications for control
Get PDFThe COVID-19 pandemic and current uncertainties about H5N1 influenza underscore the importance of vaccination for both community immunity and to prevent pathogen invasion. While the duration of a fully-immune period is often included in epidemiological models with waning immunity, the relative susceptibility to infection in fully-waned individuals and moreover their interplay that determines the shape of the trajectory of waning vaccinal immunity also may have important impacts on pathogen invasion potential. In this paper, we examine pathogen invasion outcomes with a simple mathematical framework that embeds the shape of vaccinal immunity within a buffered susceptibility framework. Using illustrative examples, we show pathogen invasion hinges on the characteristics of this shape, resulting in a large variation in outcomes. A key result is that stronger immunity (i.e. a smaller relative susceptibility in fully-waned individuals) can have a dramatic impact on such invasion characteristics, but the magnitude of this effect crucially depends on the underlying shape of immunity: the initial rate of waning is critical to the outcome. Our results highlight the importance of measuring the relative susceptibility of infection in fully-waned individuals. Additionally, they illustrate the importance of characterising host immune responses granularly and of taking this into account in pathogen-specific epidemiological models
Lottery or Triage? Controlled Experimental Evidence from the COVID-19 Pandemic on Public Preferences for Allocation of Scarce Medical Resources
Get PDFBackground: Bioethicists have advocated lotteries to distribute scarce health care resources, highlighting the benefits that make them attractive amid growing health care challenges. During the COVID-19 pandemic, lotteries were used to distribute vaccines within priority groups in some settings, notably in the United States. Nonetheless, limited evidence exists on public attitudes toward lotteries. Methods: To assess public support for vaccine allocation by lottery versus expert committee, we conducted a survey-based experiment during the pandemic. Between November 2020 and May 2021, data were collected from 15,380 respondents across 14 diverse countries. Respondents were randomly allocated (1:1) to 1 of 2 hypothetical scenarios involving COVID-19 vaccine allocation among nurses: 1) by lottery and 2) prioritization by a committee of expert physicians. The outcome was agreement on the appropriateness of the allocation mechanism on a scale ranging from 0 (strongly disagree) to 100 (strongly agree), with differences stratified by a range of covariates. Two-sided t tests were used to test for overall differences in mean agreement between lottery and expert committee. Findings: Mean agreement with lottery allocation was 37.25 (95% confidence interval [CI] 34.86–39.65), ranging from 21.1 (95% CI 15.07–27.13) in Chile to 62.33 (95% CI 54.45–70.21) in India. In every country, expert committee allocation received higher support, with mean agreement of 61.19 (95% CI: 60.04–62.35), varying from 51.25 in Chile to 69.77 in India. Greater agreement with lotteries was observed among males, higher-income individuals, those with lower education, and those identifying as politically right leaning. Conclusions: Despite arguments for lottery-based allocation of medical resources, we found low overall public support, albeit with substantial variation across countries. Successful implementation of lottery allocation will require targeted public engagement and clear communication of potential benefits. Highlights • This study surveyed 15,380 respondents from 14 diverse countries during the COVID-19 pandemic, analyzing international agreement with the appropriateness of using lottery allocation for scarce health care resources. • There was universal preference for allocating vaccines by expert committee rather than by lotteries, but there was significant variation in agreement between countries, indicating the need for region-specific policy approaches. • Successful implementation of lottery allocation requires targeted public engagement and communication of their benefits, especially with groups less supportive of lotteries.</p