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Active and stable PtPd diesel oxidation catalysts under industry-defined test protocols
No full textNanoparticle-supported Pt and Pd catalysts are employed industrially to convert CO and hydrocarbon residue from incomplete diesel fuel combustion. However, these catalysts deactivate over time due to sintering, especially for Pt nanoparticles which readily generate volatile species under high operating temperatures. Here, we turned the detrimental vapor-mediated sintering of Pt into an advantage by using a physical mixture of Pt and Pd catalysts prepared using a raspberry-colloid-templating (RCT) method. The RCT method produced Pt/Al2O3 and Pd/Al2O3 catalysts with partially embedded NPs to inhibit surface-mediated sintering pathways. As validated using an industry-defined emission control test protocol, aging a physical mixture of Pt/Al2O3 and Pd/Al2O3 at high temperature produced an alloyed PtPd/Al2O3 catalyst that outperformed the fresh catalyst mixture and both individual catalysts for hydrocarbon conversion, while exhibiting high catalytic stability and resistance to sintering and to SO2 poisoning. X-ray photoelectron spectroscopy revealed that in the aged catalyst mixture, half of the Pd content existed in their more active metallic state, compared to the less active oxide forms in the fresh mixture and both individual catalysts, explaining the unusual activity enhancement. Our results represent a practical approach to producing active and stable PtPd/Al2O3 diesel oxidation catalysts for emission control applications.Chemistry and Chemical BiologyAccepted Manuscrip
From the Patriarch's Hall Collection: The Legend and Recorded Conversations of Yàoshān Wéiyǎn
No full textThis project presents an excerpted translation of the biography and recorded sayings of Y√†oshƒÅn W√©iy«én from the Z«ît√°ng jí (Á•ñ†ÇÈõÜ, Record of the Patriarchs' Hall), a tenth-century Chan Buddhist lamp record. The translation is accompanied by a theoretically informed introduction that frames the work through a literary and heuristic methodology, emphasizing what Paul Ric≈ìur calls a ‚Äúpost-critical, second naivet√©.‚Äù Rather than reducing the text's value to questions of historical veracity or sectarian propaganda, the project reinterprets Chan lineage discourse as a symbolic and pedagogical practice grounded in relationality and dialogical immediacy. By deploying reading strategies such as protreptic dilemmas, performative contradiction, and conversational implicature, the translator aims to reorient readers toward an ‚Äúintimate reading‚Äù of encounter dialogues‚Äîone that respects the form's rhetorical subtlety and soteriological function. In doing so, this project contributes to contemporary conversations about historicity, hermeneutics, and religious pedagogy in classical Chan, and offers new ways to listen deeply to the tradition's enduring conversations.Author's Origina
Topographies of Grief
No full textTopographies of Grief is a collection of lyric essays that explore the relationship between grief, ethics, and the natural world. In conversation with scholars, writers, and artists such as Judith Butler, Virginia Woolf, and Nancy Holt, these writings are rooted in a conviction that grief attunes us to our fundamental interdependence.Author's Origina
Radical Trust: Access Services and Archives Engaged in Carceral Collecting
No full textAccess services policies at academic archives in the United States are, in many ways, informed by carceral logics. This essay explores the ethical implications of upholding such policies for academic archives engaged in the growing realm of carceral collecting. Drawing from sources in trauma theory, abolitionist and Black feminism, and critical race theory, the possibility of providing equal access in an unequal society is questioned. Opportunities for further work to increase inclusivity at archives engaged in carceral collecting are offered. These suggestions are aligned with the goal of making archives documenting the history of incarceration and abolitionist thought and action accessible to the individuals for whom the material is most urgently needed to expedite their liberation.Accepted Manuscrip
Critical quantum liquids and the cuprate high temperature superconductors
No full textPhysicsAuthor's Origina
Bioengineering Morphogenesis and Differentiation in Human Brain Organoids
No full textThe developmental processes that give rise to the distinctive human cerebral cortex are ex- perimentally inaccessible, and only partially recapitulated in animal models. Brain organoids derived from human stem cells offer a unique window into these events at the cellular level. However, organoids deviate from the single-lumen morphology and polarized tissue archi- tecture of the embryonic cortex, which orchestrate cell-cell interactions critical for normal development in vivo. Here, I develop techniques for culturing 3D in vitro human organoid mod- els of the cerebral cortex that maintain a single ventricle-like structure and display biomimetic polarization of the cortical neuroepithelium. I apply these models to investigate the role of tissue-level mechanical forces in balancing between proliferation and differentiation of neural stem cells. I find that manually inflating organoids by injection of biocompatible fluids to increase intraluminal pressure promotes the maintenance and expansion of endogenous-like tissue architecture. This injection protocol prolongs the survival of apicobasally polarized architecture from the previously reported maximum of 22 days in culture to at least 49 days, maintains this architecture as organoids grow to over a millimeter in diameter, and can preserve the overall single-lumen structure for up to three months. Leveraging the ability of this model to experimentally vary mechanical strain on human neuroepithelium-like tissue, I demonstrate that inflation of ventricular structures in organoids delays neurogenesis, favoring proliferative divisions of neural progenitors at the expense of differentiation. Conversely, pressure release is rapidly followed by an increase in neuronal differentiation. This finding suggests that mechani- cal forces naturally present in the early brain could play a key role in regulating the timing and extent of stem cell proliferation relative to differentiation, serving as a previously unrecognized driver of final cortex size and cellular composition. As a step towards future models that could enable experimental exposure of biomimetic human neuroepithelia to realistic polarized biochemical signals, I also completed the design and pilot experiments for a microfluidically perfused neural tube model. Together, my results show that organoid-derived neural stem cells retain the ability to form large-scale tissues with high fidelity to in vivo histology when provided with appropriate mechanical cues, and illustrate the potential for bioengineered brain models to investigate fundamental questions in developmental neurobiology.Biological and Biomedical Science
Dynamic subtype- and context-specific subcellular RNA regulation in growth cones of developing neurons of the cerebral cortex
No full textNeurons of distinct subtypes compartmentalize subtype-specific function in part by differentially localizing and translating specific RNAs, but underlying mechanisms are not understood. Here we investigate messenger RNA localization and stability within subtype-specific growth cones (GCs), leading tips of growing axons, of long-range projection neurons (PNs) of the developing cerebral cortex. Comparison of GC-localized transcriptomes between two subtypes of PNs (interhemispheric-callosal and corticothalamic) across developmental stages identified both distinct and shared subcellular machinery involved in distinct phases of growth, target innervation and synaptogenesis, and enrichment of genes associated with neurodevelopmental and neuropsychiatric disorders. Further, we investigated sequence elements in dynamically GC-localized mRNAs, identifying GC-enriched motifs in 3' untranslated regions. For example, we identified that CPEB4, a translational regulator, regulates axonal branching and that RBMS1 functions dynamically in callosal circuit formation. This work offers generalizable insights for subcellular specialization in other polarized cells, toward elucidating neurodevelopmental and behavioral-cognitive disorders.Stem Cell and Regenerative BiologyCenter for Brain ScienceAccepted Manuscrip
Optimal Illiquidity
No full textWe study the socially optimal level of illiquidity in an economy populated by households with taste shocks and present bias with naive beliefs. The government chooses mandatory contributions to accounts, each with a different pre-retirement withdrawal penalty. Collected penalties are rebated lump sum. When households have homogeneous present bias, β, the social optimum is well approximated by a single account with an early-withdrawal penalty of 1 − β. When households have heterogeneous present bias, the social optimum is well approximated by a two-account system: (i) an account that is completely liquid and (ii) an account that is completely illiquid until retirement.Author's Origina
A Report from core creative ideas in technical services interest group for 2025
No full textCreative Ideas in Technical Services Interest Group (CITSIG) is an interest group under the auspices of the American Library Association’s (ALA) CORE division, a nonprofit library organization. The group seeks to engage its membership through a variety of in-person and virtual mechanisms to identify new and creative approaches to technical services work. Interest Group Week, in March, is a virtual event. The ALA roundtable meetings have remained in-person events. Over the past year, CITSIG has sought to engage its members in a variety of ways.Version of Recor