Physical Sciences and Mathematics Commons^™

Life On The Edge: The Cambrian Marine Realm And Oxygenation, Sara Pruss, Benjamin C. Gill

Geosciences: Faculty Publications

The beginning of the Phanerozoic saw two biological events that set the stage for all life that was to come: (a) the Cambrian Explosion (the appearance of most marine invertebrate phyla) and (b) the Great Ordovician Biodiversification Event (GOBE), the subsequent substantial accumulation of marine biodiversity. Here, we examine the current state of understanding of marine environments and ecosystems from the late Ediacaran through the Early Ordovician, which spans this biologically important interval. Through a compilation and review of the existing geochemical, mineralogical, sedimentological, and fossil records, we argue that this interval was one of sustained low and variable marine …

Extreme Ungrading: Rewilding The Classroom Through Human-Centered Design, Johanna Brewer

Computer Science: Faculty Publications

Assessment in computer science education has grown reliant on rigid rubrics and intensive exams, a practice that yields capable yet compliant coders. In this article, I explore how we might use human-centered design to reexamine contemporary pedagogy and redesign our classrooms to cultivate a different type of programmer, one with a more critically engaged eye. Inspired by the ethos of agile development, I offer an alternative evaluation paradigm: Extreme Ungrading. Exploring results of a two-year case study applying this method to a software engineering class, this article distills actionable guidelines for enhancing learning outcomes through inclusive course development, and seeks …

Wide Range Thin-Film Ceramic Metal-Alloy Thermometers With Low Magnetoresistance, Nathanael Fortune, Joyce E. Palmer-Fortune, A. Trainer, A. Bangura, N. Kondedan, A. Rydh

Physics: Faculty Publications

Many thermal measurements in high magnetic fields require thermometers that are sensitive over a wide temperature range, are low mass, have a rapid thermal response, and have a minimal, easily correctable magnetoresistance. Here we report the development of a new granular-metal oxide ceramic composite (cermet) for this purpose formed by co-sputtering of the metallic alloy nichrome Ni0.8Cr0.2 and the insulator silcon dioxide SiO2. The resulting thin films are sensitive enough to be used from room temperature down to below 100 mK in magnetic fields up to at least 35 tesla.

Humans Against Large Language Models On Hard Paraphrase Detection Tasks, Jamie C. Macbeth, Ella Chang, Jingyu Gin Chen, Yining Hua, Sandra Grandic, Winnie X. Zheng

Computer Science: Faculty Publications

The ability to recognize that pairs or sets of language expressions “mean the same thing” is a cognitive task for which meaning representation is clearly a central issue. This paper uses the task of paraphrasing to study meaning representation in a cognitive system. The main claim is that a consequential part of the meaning representation for a natural language expression is a set of language-free structures that are not part of the expression in question. To support this claim, we construct a corpus of paraphrase pairs using a system that has a non-linguistic meaning represen- tation decoupled from the linguistic …

Ungrading For Cartographic Education: Reflections From Small Undergraduate Classes, Heather Rosenfeld

Environmental Science and Policy: Faculty Publications

No abstract provided.

The Giant Accreting Protoplanet Survey (Gaplanets)—Results From A 6 Yr Campaign To Image Accreting Protoplanets, Katherine B. Follette, Laird M. Close, Jared R. Males, Kimberly Ward-Duong, William O. Balmer, Jéa Adams Redai, Julio Morales, Catherine Sarosi, Beck Dacus, Robert J. De Rosa, Fernando Garcia Toro, Clare Leonard, Bruce Macintosh, Katie M. Morzinski, Wyatt Mullen, Joseph Palmo, Raymond Nzaba Saitoti, Elijah Spiro, Helena Treiber, Kevin Wagner, Jason Wang, David Wang, Alex Watson, Alycia J. Weinberger

Astronomy: Faculty Publications

Accreting protoplanets are windows into planet formation processes, and high-contrast differential imaging is an effective way to identify them. We report results from the Giant Accreting Protoplanet Survey (GAPlanetS), which collected Hα differential imagery of 14 transitional disk host stars with the Magellan Adaptive Optics System. To address the twin challenges of morphological complexity and point-spread function instability, GAPlanetS required novel approaches for frame selection and optimization of the Karhounen-Loéve Image Processing algorithm pyKLIP. We detect one new candidate, CS Cha “c,” at a separation of 68 mas and a modest Δmag of 2.3. We recover the HD 142527 B …

Population Modeling With Machine Learning Can Enhance Measures Of Mental Health - Open-Data Replication, Ty Easley, Ruiqi Chen, Kayla Hannon, Rosie Dutt, Janine Bijsterbosch

Statistical and Data Sciences: Faculty Publications

Efforts to predict trait phenotypes based on functional MRI data from large cohorts have been hampered by low prediction accuracy and/or small effect sizes. Although these findings are highly replicable, the small effect sizes are somewhat surprising given the presumed brain basis of phenotypic traits such as neuroticism and fluid intelligence. We aim to replicate previous work and additionally test multiple data manipulations that may improve prediction accuracy by addressing data pollution challenges. Specifically, we added additional fMRI features, averaged the target phenotype across multiple measurements to obtain more accurate estimates of the underlying trait, balanced the target phenotype's distribution …

Decomposition Of Beatty And Complementary Sequences, Geremías Polanco

Mathematics Sciences: Faculty Publications

In this paper we express the difference of two complementary Beatty sequences, as the sum of two Beatty sequences closely related to them. In the process we introduce a new Algorithm that generalizes the well known Minimum Excluded algorithm and provides a method to generate combinatorially any pair of complementary Beatty sequences.

Testing The Interaction Between A Substellar Companion And A Debris Disk In The Hr 2562 System, Stella Yimiao Zhang, Gaspard Duchêne, Robert J. De Rosa, Megan Ansdell, Quinn Konopacky, Thomas Esposito, Eugene Chiang, Malena Rice, Brenda Matthews, Paul Kalas, Bruce Macintosh, Franck Marchis, Stan Metchev, Jenny Patience, Julien Rameau, Kimberly Ward-Duong, Schuyler Wolff, Michael P. Fitzgerald, Vanessa P. Bailey, Travis S. Barman, Joanna Bulger, Christine H. Chen, Jeffrey K. Chilcotte, Tara Cotten, René Doyon, Katherine B. Follette, Benjamin L. Gerard, Stephen Goodsell, James R. Graham, Alexandra Z. Greenbaum, Pascale Hibon, Li Wei Hung

Astronomy: Faculty Publications

The HR 2562 system is a rare case where a brown dwarf companion resides in a cleared inner hole of a debris disk, offering invaluable opportunities to study the dynamical interaction between a substellar companion and a dusty disk. We present the first ALMA observation of the system as well as the continued Gemini Planet Imager monitoring of the companion's orbit with six new epochs from 2016 to 2018. We update the orbital fit, and in combination with absolute astrometry from GAIA, place a 3σ upper limit of 18.5 M J on the companion's mass. To interpret the ALMA observations, …

Climate Change And Labor Reallocation: Evidence From Six Decades Of The Indian Census, Maggie Liu, Yogita Shamdasani, Vis Taraz

Environmental Science and Policy: Faculty Publications

No abstract provided.

Repytah: An Open-Source Python Package For Building Aligned Hierarchies For Sequential Data, Chenhui Jia, Lizette Carpenter, Thu Tran, Amanda Y. Liu, Sasha Yeutseyva, Mariun Tapal, Yingke Wang, Zoie Kexin Zhou, Jordan Moody, Denise Nava, Eleanor Donaher, Lillian Yusha Jiang, Ben Bruncati, Katherine M. Kinnaird

Computer Science: Faculty Publications

We introduce repytah, a Python package that constructs the aligned hierarchies representation that contains all possible structure-based hierarchical decompositions for a finite length piece of sequential data aligned on a common time axis. In particular, this representation–introduced by Kinnaird (2016) with music-based data (like musical recordings or scores) as the primary motivation–is intended for sequential data where repetitions have particular meaning (such as a verse, chorus, motif, or theme). Although the original motivation for the aligned hierarchies representation was finding structure for music-based data streams, there is nothing inherent in the construction of these representations that limits repytah to only …

Interspecies Differences In Food Sources For The Tropical Callichirid Shrimp Neocallichirus Spp. On San Salvador Island, Bahamas, Koji Seike, H. Allen Curran

Geosciences: Faculty Publications

At least 4 species of callichirid shrimp coexist in the shallow marine settings of San Salvador Island, an isolated, small platform of the all-carbonates Bahama Archipelago, implying that interspecific competition or trophic niche segregation occurs between these shrimp species. Carbon and nitrogen stable isotope analyses were conducted on soft tissues of 3 callichirid species, Neocallichirus cacahuate, N. grandimana, and N. maryae, to determine the food sources for each species. These analyses revealed that the isotopic trophic niches for these 3 species do not overlap. The most important food source for all 3 species was manatee grass Syringodium filiforme …

A Diffusion Network Event History Estimator, Jeffrey J. Harden, Bruce A. Desmarais, Mark Brockway, Frederick J. Boehmke, Scott J. Lacombe, Fridolin Linder, Hanna Wallach

Government: Faculty Publications

Research on the diffusion of political decisions across jurisdictions typically accounts for units’ influence over each other with (1) observable measures or (2) by inferring latent network ties from past decisions. The former approach assumes that interdependence is static and perfectly captured by the data. The latter mitigates these issues but requires analytical tools that are separate from the main empirical methods for studying diffusion. As a solution, we introduce network event history analysis (NEHA), which incorporates latent network inference into conventional discrete-time event history models. We demonstrate NEHA’s unique methodological and substantive benefits in applications to policy adoption in …

Iron-Catalyzed Oxidative Α-Amination Of Ketones With Primary And Secondary Sulfonamides, Fubin Song, So Hyun Park, Christine Wu, Alexandra E. Strom

Chemistry: Faculty Publications

We report the iron-catalyzed α-amination of ketones with sulfonamides. Using an oxidative coupling approach, ketones can be directly coupled with free sulfonamides, without the need for prefunctionalization of either substrate. Primary and secondary sulfonamides are both competent coupling partners, with yields from 55% to 88% for deoxybenzoin-derived substrates.

Institutional Design And Policy Responsiveness In Us States, Scott J. Lacombe

Government: Faculty Publications

There is significant disagreement on the moderating role of institutions on policy responsive- ness, yet overwhelmingly research in state politics has focused on single institutions. This project leverages a new aggregate scale of state institutions to evaluate if the collective insti- tutional context moderates the influence of public opinion on policy. I use a recently released latent scale of institutional context and find that high levels of accountability pressure strongly strengthen public opinion’s influence on policy for both economic and social policy, while the strength of a state’s checks and balance system is largely unrelated to policy responsiveness. These results …

Aggregate Effects Of Proliferating Low-Earth-Orbit Objects And Implications For Astronomical Data Lost In The Noise, John C. Barentine, Aparna Venkatesan, Jessica Heim, James Lowenthal, Miroslav Kocifaj, Salvador Bará

Astronomy: Faculty Publications

The rising population of artificial satellites and associated debris in low-altitude orbits is increasing the overall brightness of the night sky, threatening ground-based astronomy as well as a diversity of stakeholders and ecosystems reliant on dark skies. We present calculations of the potentially large rise in global sky brightness from space objects in low Earth orbit, including qualitative and quantitative assessments of how professional astronomy may be affected. Debris proliferation is of special concern: we calculate that all log-decades in debris size contribute approximately the same amount of night sky radiance, so debris-generating events are expected to lead to a …

Correlating Changes In Spot Filling Factors With Stellar Rotation: The Case Of Lkca 4, Facundo Pérez Paolino, Jeffrey S. Bary, Michael S. Petersen, Kimberly Ward-Duong, Benjamin M. Tofflemire, Katherine B. Follette, Heidi Mach

Astronomy: Faculty Publications

We present a multi-epoch spectroscopic study of LkCa 4, a heavily spotted non-accreting T Tauri star. Using SpeX at NASA’s Infrared Telescope Facility (IRTF), 12 spectra were collected over five consecutive nights, spanning ≈1.5 stellar rotations. Using the IRTF SpeX Spectral Library, we constructed empirical composite models of spotted stars by combining a warmer (photosphere) standard star spectrum with a cooler (spot) standard weighted by the spot filling factor, f spot. The best-fit models spanned two photospheric component temperatures, T phot = 4100 K (K7V) and 4400 K (K5V), and one spot component temperature, T spot = 3060 K (M5V) …

Direct Discovery Of The Inner Exoplanet In The Hd 206893 System: Evidence For Deuterium Burning In A Planetary-Mass Companion, S. Hinkley, S. Lacour, G. D. Marleau, A. M. Lagrange, J. J. Wang, J. Kammerer, A. Cumming, M. Nowak, L. Rodet, T. Stolker, W. O. Balmer, S. Ray, M. Bonnefoy, P. Mollière, C. Lazzoni, G. Kennedy, C. Mordasini, R. Abuter, S. Aigrain, A. Amorim, R. Asensio-Torres, C. Babusiaux, M. Benisty, J. P. Berger, H. Beust, S. Blunt, A. Boccaletti, Kimberly Ward-Huong, Et Al

Astronomy: Faculty Publications

Aims. HD 206893 is a nearby debris disk star that hosts a previously identified brown dwarf companion with an orbital separation of ~ 10 au. Long-Term precise radial velocity (RV) monitoring, as well as anomalies in the system proper motion, has suggested the presence of an additional, inner companion in the system. Methods. Using information from ongoing precision RV measurements with the HARPS spectrograph, as well as Gaia host star astrometry, we have undertaken a multi-epoch search for the purported additional planet using the VLTI/GRAVITY instrument. Results. We report a high-significance detection over three epochs of the companion HD 206893c, …

The Jwst Early-Release Science Program For Direct Observations Of Exoplanetary Systems Ii: A 1 To 20 Μm Spectrum Of The Planetary-Mass Companion Vhs 1256-1257 B, Brittany E. Miles, Beth A. Biller, Polychronis Patapis, Kadin Worthen, Emily Rickman, Kielan K.W. Hoch, Andrew Skemer, Marshall D. Perrin, Niall Whiteford, Christine H. Chen, B. Sargent, Sagnick Mukherjee, Caroline V. Morley, Sarah E. Moran, Mickael Bonnefoy, Simon Petrus, Aarynn L. Carter, Elodie Choquet, Sasha Hinkley, Kimberly Ward-Duong, Jarron M. Leisenring, Maxwell A. Millar-Blanchaer, Laurent Pueyo, Shrishmoy Ray, Steph Sallum, Karl R. Stapelfeldt, Jordan M. Stone, Jason J. Wang, Olivier Absil, William O. Balmer, Anthony Boccaletti, Mariangela Bonavita

Astronomy: Faculty Publications

We present the highest fidelity spectrum to date of a planetary-mass object. VHS 1256 b is a (∼8″, a = 150 au), young, planetary-mass companion that shares photometric colors and spectroscopic features with the directly imaged exoplanets HR 8799c, d, and e. As an L-to-T transition object, VHS 1256 b exists along the region of the color-magnitude diagram where substellar atmospheres transition from cloudy to clear. We observed VHS 1256 b with JWST's NIRSpec IFU and MIRI MRS modes for coverage from 1 to 20 μm at resolutions of ∼1000-3700. Water, methane, carbon monoxide, carbon dioxide, sodium, and potassium are …

Coral Gardens Reef, Belize: An Acropora Spp. Refugium Under Threat In A Warming World, Lisa Greer, H. Allen Curran, Karl Wirth, Robert Humston, Ginny Johnson, Lauren Mcmanus, Candice Stefanic, Tara Clark, Halard Lescinsky, Kirah Forman-Castillo

Geosciences: Faculty Publications

Live coral cover has declined precipitously on Caribbean reefs in recent decades. Acropora cervicornis coral has been particularly decimated, and few Western Atlantic Acropora spp. refugia remain. Coral Gardens, Belize, was identified in 2020 as a long-term refugium for this species. This study assesses changes in live A. cervicornis coral abundance over time at Coral Gardens to monitor the stability of A. cervicornis corals, and to explore potential threats to this important refugium. Live coral cover was documented annually from 2012– 2019 along five permanent transects. In situ sea-surface temperature data were collected at Coral Gardens throughout the study period …

The Giant Accreting Protoplanet Survey (Gaplanets): Optimization Techniques For Robust Detections Of Protoplanets, Jéa I. Adams Redai, Katherine B. Follette, Jason Wang, Clare Leonard, William Balmer, Laird M. Close, Beck Dacus, Jared R. Males, Katie M. Morzinski, Joseph Palmo, Laurent Pueyo, Elijah Spiro, Helena Treiber, Kimberly Ward-Duong, Alex Watson

Astronomy: Faculty Publications

High-contrast imaging has afforded astronomers the opportunity to study light directly emitted by adolescent (tens of megayears) and “proto” (<10 >Myr) planets still undergoing formation. Direct detection of these planets is enabled by empirical point-spread function (PSF) modeling and removal algorithms. The computational intensity of such algorithms, as well as their multiplicity of tunable input parameters, has led to the prevalence of ad hoc optimization approaches to high-contrast imaging results. In this work, we present a new, systematic approach to optimization vetted using data of the high-contrast stellar companion HD 142527 B from the Magellan Adaptive Optics Giant Accreting Protoplanet …

Fossil Fuel Divestment In U.S. Higher Education: Endowment Dependence And Temporal Dynamics, Alexander R. Barron, Rachel C. Venator, Ella V.H. Carlson, Jane K. Andrews, Junwen Ding, David Deswert

Environmental Science and Policy: Faculty Publications

Since 2012, students and others have pushed U.S. Higher Education Institutions (HEIs) to divest their endowments from fossil fuel producing industries. In the past decade, fossil fuel divestment has become the fastest growing divestment movement in history, with over 140 U.S. HEIs announcing divestment commitments. We conduct a quantitative analysis of the three phases of U.S. 4-year HEI divestment announcements (as well as rejections of divestment) to better understand the dynamics. Announcements began (2012-2017) with a number of schools divesting, followed by a second phase where new divestment announcements slowed. The current phase, which began around 2019, shows a renewed …

Modules And Representations Up To Homotopy Of Lie N-Algebroids, M. Jotz, Rajan Amit Mehta, T. Papantonis

Mathematics Sciences: Faculty Publications

This paper studies differential graded modules and representations up to homotopy of Lie n-algebroids, for general n ∈ N. The adjoint and coadjoint modules are described, and the corresponding split versions of the adjoint and coadjoint representations up to homotopy are explained. In particular, the case of Lie 2-algebroids is analysed in detail. The compatibility of a Poisson bracket with the homological vector field of a Lie n-algebroid is shown to be equivalent to a morphism from the coadjoint module to the adjoint module, leading to an alternative characterisation of non-degeneracy of higher Poisson structures.Moreover, theWeil algebra of a …

Bringing Stakeholders Along For The Ride: Towards Supporting Intentional Decisions In Software Evolution: Supplemental Material, Alicia M. Grubb, Paola Spoletini

Data

Supplemental material for the research paper entitled, "Bringing Stakeholders Along for the Ride: Towards Supporting Intentional Decisions in Software Evolution". This paper presents an initial literature review to define intentionality, disambiguate it from its use in literature, and position it in relation to similar concepts. This supplement contains the literature review data file.

Spatially Resolved Imaging Of The Inner Fomalhaut Disk Using Jwst/Miri, András Gáspár, Schuyler Grace Wolff, George H. Rieke, Jarron M. Leisenring, Jane Morrison, Kate Y.L. Su, Kimberly Ward-Duong, Jonathan Aguilar, Marie Ygouf, Charles Beichman, Jorge Llop-Sayson, Geoffrey Bryden

Astronomy: Faculty Publications

Planetary debris disks around other stars are analogous to the asteroid and Kuiper belts in the Solar System. Their structure reveals the configuration of small bodies and provides hints for the presence of planets. The nearby star Fomalhaut hosts one of the most prominent debris disks, resolved by the Hubble Space Telescope, Spitzer, Herschel and the Atacama Large Millimeter Array. Images of this system at mid-infrared wavelengths using JWST/MIRI not only show the narrow Kuiper belt-analogue outer ring, but also that (1) what was thought from indirect evidence to be an asteroid-analogue structure is instead broad, extending outward into the …

Cylindrical Mega-Voids In Quaternary Aeolianites, Little Exuma Island, The Bahamas: Georadar Response, Ilya Val Buynevich, H. Allen Curran, Bosiljka Glumac, Michael Savarese, Lisa Park Boush

Geosciences: Faculty Publications

In addition to karst features, tropical carbonates contain a wide range of smaller cylindrical voids (“pipes”) attributed to bioturbation, tree molds, or dissolution, among others. During geophysical investigation of the Little Exuma Island, The Bahamas, several sites with enigmatic voids were investigated using a high-frequency ground-penetrating radar (GPR) imaging.

The aim of the paper is to assess the feasibility of GPR to detect voids within lithified Holocene calcarenites of the Hannah Bay Member

Public Works Programmes And Agricultural Risk: Evidence From India, Vis Taraz

Environmental Science and Policy: Faculty Publications

The agricultural sectors in many low-and middle-income countries remain highly vulnerable to weather risk, a vulnerability that will only intensify under climate change. The globally trending public works programmes have the potential to impact weather-related agricultural risk. I explore the impact of India's National Rural Employment Guarantee Act (NREGA) on weather-related agricultural risk. My empirical strategy explores the staggered roll-out of NREGA and random weather fluctuations. Using a nationwide panel of data, I find that NREGA makes crop yields more sensitive to low rainfall shocks. I posit that these results are consistent with a labour market channel, by which NREGA …

The Impact Of Weather Shocks On Employment Outcomes: Evidence From South Africa, Harriet Margaret Brookes Gray, Vis Taraz, Simon Halliday

Environmental Science and Policy: Faculty Publications

Climate change is increasing the frequency of extreme weather events, such as drought and heat waves. In this paper, we assess the impact of drought and high temperatures on the employment outcomes of working-age individuals in South Africa between 2008 and 2017. We merge high-resolution weather data with detailed individual-level survey data on labor market outcomes, and estimate causal impacts using a fixed effects framework. We find that increases in the occurrence of drought reduce overall employment. These effects are concentrated in the tertiary sector, amongst informal workers, and in provinces with a higher reliance on tourism. Taken together, our …

Neoichnological Framework Of Coastal Habitat Shifts Represented By Bahamian Decapod Burrows, Ilya Val Buynevich, Karen Kopcznski, Christopher Sparacio, H. Allen Curran

Geosciences: Faculty Publications

In coastal settings, the cumulative spatial and temporal impacts of burrowing, ichnofabric formation, and biodeposition by large crustaceans have been largely neglected at zoogeomorphic scales. These traces also serve as important (paleo-)environmental and (paleo)hydrologic indicators, both vertical (tidal or groundwater level) and lateral (areal wetland or basin extent). To date, 354 only few studies have addressed the comparative value of decapod ichnites generated by land crabs in carbonate settings. The aim of this paper is to introduce a general conceptual framework for burrows created by three crab species in the Bahama Archipelago, using examples from San Salvador Island.

An Experiment On The Effects Of Using Color To Visualize Requirements Analysis Tasks: Supplemental Material, Yesugen Baatartogtokh, Irene Foster, Alicia M. Grubb

Computer Science: Faculty Publications

Supplemental material for the paper: "An Experiment on the Effects of using Color to Visualize Requirements Analysis Tasks".
This paper is a scientific evaluation of the effectiveness and usability of EVO. We conduct an experiment to measure any effect of using colors to represent evidence pairs.