University of Colorado Boulder

Distance-spectral classification of twelve-point kissing shells in three dimensions

Let D={1,2,8/3,3,11/3,4}, the set of squared distances realised between two points of one twelve-neighbour shell of a Barlow (close-packed) structure. Call a twelve-point subset of the unit sphere distance-spectral if all of its pairwise squared distances lie in D. We prove that...

Distance-spectral classification of twelve-point kissing shells in three dimensions

Let D={1,2,8/3,3,11/3,4}, the set of squared distances realised between two points of one twelve-neighbour shell of a Barlow (close-packed) structure. Call a twelve-point subset of the unit sphere distance-spectral if all of its pairwise squared distances lie in D. We prove that...

Streamlining analysis and design of two-dimensional electronic spectroscopy using machine learning

Two-dimensional electronic spectroscopy (2DES) offers unique insights into the coupling between electronic and nuclear motion and dynamics, making it a key technique in diverse fields, including materials science and biology. Obtaining 2DES data requires a series of measurements...

Exploring divergent long-term stratospheric aerosol injection scenarios with the G2-SAI and ARISE-hybrid experiments

Abstract. Stratospheric aerosol injection (SAI) simulations are often short relative to climatic timescales and conducted against a background that evolves due to changes in anthropogenic greenhouse gas emissions and other forcings. This can cause challenges in assessing certain...

What Should We Listen for in Social Studies Discussions?

Built around four social studies-specific dimensions—content, source scrutiny, empathic imagination, and ethical action—the Social Studies Discourse Instrument gives teachers a fresh, nonevaluative lens on classroom discussion.

???Setting the Conversation on Fire???: What Youth Want from Social Studies Discussions

Feedback from more than 100 high school students reveals what makes classroom discussions work—from crafting open-ended questions to balancing teacher participation.

Gravity Wave Energy Baselines (∼30–110 km) Established From Lidar Observations at McMurdo (77.84°S, 166.67°E), Antarctica: Energy Dissipation and Constituent Diffusion

Abstract Lidar observations above McMurdo, Antarctica from 2011 to 2024 are used to characterize gravity wave (GWs) potential energies () in the mesosphere and lower thermosphere (MLT). Alongside characterizations in the middle atmosphere (30–70 km), the GW baselines show dissipa...

A Clifford algebra approach to bosonic strings with fermionic boundaries

Abstract The Brauer–Weyl theorem (Brauer, Weyl. 1935 Am. J. Maths. 57, 425–449. (doi:10.2307/2371218)) states that the algebra of tensor products of spinors is isomorphic to the Clifford (geometric) algebra, in any number of space–time dimensions. The algebraic relation between f...

Vibrational Spectraof Anionic Polycyclic AromaticHydrocarbons in the CH Stretching Region: Anthracene, Pyrene, Perylene,and Fluoranthene

Abstract The CH stretching region of the infrared spectra of polycyclic aromatic hydrocarbon radical anions (2700–3100 cm–1) is characterized by complicated band patterns that defy straightforward assignments from harmonic calculations. We compare experimental infrared photodisso...

From Posts to Perceptions: How Reddit Users Feel About Phalloplasty and Metoidioplasty

Abstract Gender-affirming surgery, including phalloplasty and metoidioplasty, has demonstrated efficacy in alleviating gender dysphoria in appropriately selected patients. This study aims to better describe the needs and priorities of patients undergoing these procedures by using...

Understandingthe Electronic Structure of RutheniumOxides during Redox Cycling with High Energy Resolution X-rayAbsorption Spectroscopy

Abstract Ruthenium oxides are essential catalysts and charge storage materials whose performance across reactions, from the oxygen evolution reaction to the chlor-alkali process, depends critically on reversible Ru redox cycling and the associated electronic structure changes. Al...

Middle atmosphere chemical and dynamical effects in the CCMI-2022 stratospheric aerosol injection scenario

Abstract. Stratospheric aerosol injection (SAI) could slow surface warming, however, potential side effects include changes in stratospheric ozone and changes in regional surface temperatures and precipitation resulting from tropical lower stratospheric warming. Previous multi-mo...

Longitudinal changes in gut microbiota across reproductive states in wild baboons

Background: In humans and other mammals, female reproduction is linked to extensive changes in physiology, immunity, hormones, and behavior. These changes likely shape, and may be shaped by, the composition of gut microbial communities. Characterizing the dynamics of gut microbia...

Total Ozone Reactivity Measurements Reveal Knowledge Gap in Volatile Organic Compound Emissions and Their Reactions

Abstract Total ozone (O 3 ) reactivity monitors (TORMs) were used to investigate biogenic volatile organic compound (BVOC) emissions from several ecosystems. Measurements were conducted in temperate deciduous North American forests, during the CABINEX and SOAS campaigns, on tundr...

Technical note: Design, construction, automation, and first-principles calibration of a low volume He measurement line

Abstract. A noble-gas analysis line capable of accurate and precise measurements of small absolute amounts of 4He released from crystals is a key analytical step in the production of (U-Th)/He chronologic data. He analysis lines that are custom-built in-house can be optimized for...

Regional FireworksPollution over East and SoutheastAsia from Airborne Observations around the Spring Festival Period

Abstract Fireworks are spectacular, but they also pollute the atmosphere. While fireworks are known to rapidly increase local pollution levels, the regional influences and nanosized appearance of fireworks-related particles are poorly understood. This study collected aerosol part...

Trions as Fundamental Species in Chemically Doped Polymer Semiconductors

Doping is a cornerstone strategy for enhancing charge transport in semiconducting polymers, important for their application in, for example, semi-transparent electrode materials, thermoelectric devices, and antistatic coatings. Both chemical and electrochemical doping have, for t...

How AI induces professional identity threats: A survey study with public relations professionals

The transformative force of AI is largely redefining how public relations professionals approach their work, understand their responsibilities, and make sense of the meaning and value associated with being a PR practitioner. While research in other disciplines have increasingly r...

The Fertility Reduction Effects of the Colorado Family Planning Initiative by Age and Parity

ABSTRACT We use restricted‐access birth records from the National Vital Statistics System (NVSS) to document the full age and parity fertility effects of the Colorado Family Planning Initiative (CFPI). The CFPI provided access to every FDA approved method of contraception for fre...

A trace pairing and Elliott invariant for groupoid homology

Abstract For an étale groupoid, we define a pairing between the Crainic–Moerdijk groupoid homology and the simplex of invariant Borel probability measures on the base space. The main novelty here is that the groupoid need not have totally disconnected base space, and thus the pai...