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Global impact of anthropogenic NH<sub>3</sub> emissions on upper tropospheric aerosol formation
No full textAnthropogenic ammonia (NH 3 ) emissions have significantly increased in recent decades due to enhanced agricultural activities, contributing to global air pollution. While the effects of NH 3 on surface air quality are well documented, its influence on particle dynamics in the upper troposphere-lower stratosphere (UTLS) and related aerosol impacts remain unquantified. NH 3 reaches the UTLS through convective transport and can enhance new particle formation (NPF). This modeling study evaluates the global impact of anthropogenic NH 3 on UTLS particle formation and quantifies its effects on aerosol loading and cloud condensation nuclei (CCN) abundance. We use the EMAC Earth system model, incorporating multicomponent NPF parameterizations from the CERN CLOUD experiment. Our simulations reveal that convective transport increases NH 3 -driven NPF in the UTLS by one to three orders of magnitude compared to a baseline scenario without anthropogenic NH 3 , causing a doubling of aerosol numbers over high-emission regions. These aerosol changes induce a 2.5-fold increase in upper tropospheric CCN concentrations. Anthropogenic NH 3 emissions increase the relative contribution of water-soluble inorganic ions to the UTLS aerosol optical depth (AOD) by 20% and increase total column AOD by up to 80%. In simulations without anthropogenic NH 3 , UTLS aerosol composition is dominated by sulfate and organic species, with a marked reduction in ammonium nitrate and aerosol water content. This results in a decline of aerosol mass concentration by up to 50%. These findings underscore the profound global influence of anthropogenic NH 3 emissions on UTLS particle formation, AOD, and CCN production, with important implications for cloud formation and climate. </p
Mapping Chicagoland: A Collaborative Model for Digitizing Chicago’s Historical Maps
No full textMapping Chicagoland is a National Endowment for the Humanities (NEH)-funded project to make openly available over 5,000 georeferenced historical maps of Chicago from three institutions: The Chicago History Museum, the Newberry Library, and the University of Chicago Library. Mapping Chicagoland strategically deployed collaboration at phases that benefited most – such as map selection, staffing, metadata creation, and user engagement – while leveraging centralized coordination for digital workflows. This paper presents the processes and decision points shaped by partnership, explores where collaboration enabled broader coverage and continuity, and discusses lessons learned in choosing when to collaborate and when to streamline. This model of collaboration resulted in a more diverse digital collection, deeper institutional memory, and an increased public impact. The resulting open-access, georeferenced map images enable scholars worldwide to pursue broad research goals and incorporate maps and spatial data into their teaching
Mapping persistence and change in psychological problems during the transition to adolescence: Adding, subtracting, shifting, and persisting
Get PDFBackground: Recent developmental models posited that general tendencies to exhibit psychological problems are relatively stable, but specific problems change frequently. We need comprehensive descriptions of persistence and change in psychological problems before advancing such theories, however. Methods: Data from four annual assessments of 9806 children (ages 9–10 years at baseline) in the Adolescent Behavior Cognitive Development Study™ were used to quantify persistence and change in each of 10 parent-rated specific psychological problems. Results: Novel pairwise analyses revealed that the persistence of psychological problems over 1–3 years was common, but behavior change in the sense that problem x1 at baseline desisted and was replaced by a new problem y2 at follow-up was uncommon. The only relatively common changes in behavior over time involved adding a new problem (i.e., x1 at baseline followed by x2 + y2 at follow-up) or subtracting a problem (i.e., x1 + y1 at baseline followed by only y2 at follow-up). Conclusions: If confirmed across other measures and developmental epochs, these findings challenge a key postulate of current theories that the developmental course of psychological problems involves frequent replacement of one problem by another.</p
Methamphetamine-induced adaptation of learning rate dynamics depend on baseline performance
Get PDFThe ability to calibrate learning according to new information is a fundamental component of an organism’s ability to adapt to changing conditions. Yet, the exact neural mechanisms guiding dynamic learning rate adjustments remain unclear. Catecholamines appear to play a critical role in adjusting the degree to which we use new information over time, but individuals vary widely in the manner in which they adjust to changes. Here, we studied the effects of a low dose of methamphetamine (MA), and individual differences in these effects, on probabilistic reversal learning dynamics in a within-subject, double-blind, randomized design. Participants first completed a reversal learning task during a drug-free baseline session to provide a measure of baseline performance. Then they completed the task during two sessions, one with MA (20 mg oral) and one with placebo (PL). First, we showed that, relative to PL, MA modulates the ability to dynamically adjust learning from prediction errors. Second, this effect was more pronounced in participants who performed moderately low at baseline. These results present novel evidence for the involvement of catecholaminergic transmission on learning flexibility and highlights that baseline performance modulates the effect of the drug
Bipartite Fluctuations of Critical Fermi Surfaces
Get PDFFluctuations of conserved quantities within a subsystem are nonlocal observables that provide unique insights into quantum many-body systems. In this paper, we study bipartite charge (and spin) fluctuations across interaction-driven “metal-insulator transitions” out of Landau Fermi liquids. The “charge insulators” include a class of non-Fermi-liquid states of fractionalized degrees of freedom, such as compressible composite Fermi liquids (for spinless electrons) and incompressible spin-liquid Mott insulators (for spin-1/2 electrons). We find that charge fluctuations ℱ exhibit distinct leading-order scalings across the transition: ℱ ∼log() in Landau Fermi liquids and ℱ ∼ in charge insulators, where is the linear size of the subsystem. In composite Fermi liquids, under certain conditions, we also identify a universal constant term −f()||/(2) when the subsystem geometry contains a sharp corner, where f() denotes a function of the corner angle and is the Hall conductivity. At the critical point, provided the transition is continuous, the leading scaling ℱ ∼ is accompanied by a subleading universal corner contribution −log()f()/2 with the same angle dependence f(), and the universal coefficient is directly related to the predicted universal jumps in longitudinal and Hall resistivities. These results establish fluctuation-transport relations, paving the way for numerical and experimental studies of unconventional quantum criticalities in metals
Bridging the pyridine-pyridazine synthesis gap by skeletal editing
No full textPairs of heterocycles differing by a single constitutive ring atom can exhibit stark differences in the retrosynthetic disconnections available for their preparation. Such a synthesis gap is exemplified by pyridine and pyridazine. Pyridine (a six-membered C5N ring) has risen to prominence in discovery chemistry, its ease of assembly spurring further synthetic development. Despite a host of favorable properties, pyridazine (an analogous C4N2 ring) has comparatively lagged behind—a discrepancy attributable to its often-challenging preparation, which arises from an electronically dissonant heteroatom arrangement. In this work, we achieve a single-atom skeletal edit that produces pyridazines from pyridines by direct carbon-to-nitrogen atom replacement: Azide introduction at the ortho position enables a photoinitiated rearrangement of N-amino-2-azidopyridinium cations. This transformation links the two heterocycles such that the richness of pyridine retrosynthesis becomes available to pyridazines
Algorithmic Persuasion: Exploring the Role of Sentiment and "Quotation" in AI‐Generated Review Summaries
No full textThe rapid rise of AI-generated summaries (AIGS) is transforming how consumers navigate online review environments. While prior work has highlighted platform-level outcomes, little is known about its persuasive effects. To address this gap, we investigate how sentiment orientation and the presence of quotation marks in AI-generated review summaries influence consumer evaluation and behavioral intentions. Across four preregistered experiments (N > 3,000), we find that AI-generated summaries that emphasize positive sentiment inflate predicted ratings and narrow perceived differences between high- and low-rated restaurants, while quotation marks enhance evaluations but reduce review exploration, particularly when other evaluative cues (e.g., star ratings or access to individual reviews) are unavailable. Together, these findings demonstrate that the linguistic and stylistic cues in AIGS can meaningfully influence consumer judgment and decision-making
The New AI Powered Classroom: Implications for Students, Teachers, and Equity
No full textFollowing President Trump’s Executive Order on Advancing Artificial Intelligence Education for American Youth in April 2025, a new national vision of AI emerged in classrooms meant to meet job market demands and keep up with international competition. The new AI-powered classroom is envisioned as a world where AI becomes an educator. AI provides instructional material, analyzes student performance in real time, and adapts to student needs at unprecedented speeds. While many AI enthusiasts may call this an opportunity to bridge the achievement gap, I propose that AI instruction is likely to exacerbate current structural inequalities pertaining to unequal funding, infrastructure, and support. In this paper, I will utilize California as a case study due to its proximity to Silicon Valley and its elevated levels of income inequality to investigate the implications AI has on students, teachers, and equity. Through an integrated study of (1) interviews with professors at the University of Chicago and primary school teachers in California and (2) a quantitative exploratory data analysis of student outcomes, I outline current barriers to equity and the effects of AI on education
The Development of Socioeconomic Cognition in Childhood
No full text Economic inequality is a pressing social issue affecting children's development. Children are not simply passive recipients of outcomes associated with their family's socioeconomic status; rather, children begin to build a map of socioeconomic concepts early in life—reasoning about what money is, its role in their own and others’ lives, and why some people have more of it than others. This article draws from disparate social science disciplines to articulate a cognitive development framework for understanding children's socioeconomic reasoning across four domains ranging from concrete to abstract: ( a ) reasoning about money as currency, ( b ) reasoning about money as wealth held by people, ( c ) reasoning about wealth as an aspect of a person's identity, and ( d ) reasoning about wealth as a source of societal-level inequality. Across domains, we synthesize existing research, summarize common themes across fields, and highlight pressing questions to provide a roadmap for the continued study of children's socioeconomic cognition. </p
Loneliness is not associated with attention interference of negative social information: Evidence from four studies
Get PDFExtended experiences of loneliness, defined as perceived social isolation, are associated with lasting impacts on health outcomes. One proposed mechanism through which loneliness contributes to health risk is heightened vigilance to cues of social threat resulting in extended activation of stress responses systems. This heightened vigilance is thought to be driven by loneliness-related shifts in a variety of cognitive and affective processes, though the differential effects of loneliness on specific stages of processing remain unclear. The present study examined four datasets using individual participant data meta-analytical techniques to test the link between loneliness and attention interference to social threat cues in an Emotional Stroop task. Despite existing theoretical frameworks predicting heightened attentional interference for negative social information in lonely individuals, we found no support for this effect across the four samples. These findings highlight the need for further work delving into the complex interplay between distinct perceptual processes associated with loneliness and how they contribute to the maintenance of loneliness states over time.</p