Digital Commons Network^™

Size Fractionation Informs Microbial Community Composition And Interactions In The Eastern Tropical North Pacific Ocean, Madeleine A. Thompson, David L. Valentine, Xuefeng Peng

Faculty Publications

Marine microorganisms are drivers of biogeochemical cycles in the world’s oceans, including oxygen minimum zones (OMZs). Using a metabarcoding survey of the 16S rRNA gene, we investigated prokaryotic communities, as well as their potential interactions with fungi, at the coastal, offshore, and peripheral OMZ of the eastern tropical North Pacific. Water samples were collected along a vertical oxygen gradient, and large volumes were filtered through three size fractions, 0.22, 2, and 22 µm. The changes in community composition along the oxygen gradient were driven by Planctomycetota, Bacteroidota, Verrucomicrobiota, and Gammaproteobacteria; most are known degraders of marine polysaccharides and usually associated …

Acclaimed Children's Literature As Global Resources, Sunah Chung, Melanie D. Koss, Kathleen A. Paciga

Faculty Publications

Acclaimed children's books in the United States (U.S.) may be utilized as resources to instruct global issues. As children’s literature reflects social context and values, acclaimed books may provide curricular materials for those within the U.S. and to international audiences. Stakeholders, including librarians, teachers, national industry experts, and parents, are among those who review and award prizes to children’s literature. This work has resulted in booklists teachers, families, and librarians use to guide their book purchasing and sharing practices. We investigate the histories, composition, and criteria for 22 award and acclaimed U.S. children’s book lists containing 4,244 titles. Fewer than …

A Panel Data Regression Model For Defense Merger And Acquisition Activity, Corey D. Mack, Clay Koschnick, Michael Brown, Jonathan D. Ritschel, Brandon M. Lucas

Faculty Publications

Excerpt: This paper examines the relationship between a prime contractor's financial health and its mergers and acquisitions (M&A) spending in the defense industry. It aims to provide models that give the United States Department of Defense (DoD) indications of future M&A activity, informing decision-makers and contributing to ensuring competitive markets that benefit the consumer.

The results show a significant relationship between efficiency and M&A spending, indicating that companies with lower efficiency tend to spend more on M&As. However, there was no significant relationship between M&A spending and a company's profitability or solvency. These results were consistent with previous research and …

The Past And Future Of The Fisheries And Marine Ecosystem Model Intercomparison Project, Camilla Novaglio, Andrea Bryndum-Buchholz, Derek P. Tittensor, Tyler D. Eddy, Heike K. Lotze, Cheryl S. Harrison, Ryan F. Heneghan, Olivier Maury, Kelly Ortega-Cisneros, Colleen M. Petrik, Kelsey E. Roberts, Julia L. Blanchard

Faculty Publications

Climate change is increasingly affecting the world's ocean ecosystems, necessitating urgent guidance on adaptation strategies to limit or prevent catastrophic impacts. The Fisheries and Marine Ecosystem Model Intercomparison Project (FishMIP) is a network and framework that provides standardised ensemble projections of the impacts of climate change and fisheries on ocean life and the benefits that it provides to people. Since its official launch in 2013 as a small, self-organized project within the larger Inter-Sectoral Impact Model Intercomparison Project, the FishMIP community has grown substantially and contributed to key international policy processes, such as the Intergovernmental Panel on Climate Change Assessment …

Far From Their Origins: A Transcriptomic Investigation On How 2,4-Di-Tert-Butyl-6-(5-Chloro-2h-Benzotriazol-2-Yl) Phenol Affects Rainbow Trout Alevins, Andreas N.M. Eriksson, Justin Dubiel, Alper James Alcaraz, Jon A. Doering, Steve Wiseman

Faculty Publications

Benzotriazole ultraviolet stabilizers (BUVSs) are a group of widely used chemicals added to a variety of consumer (e.g., plastics) and industrial (e.g., metal coating) goods. Although detected globally as an environmentally persistent pollutant, BUVSs have received relatively little toxicological attention and only recently have been acknowledged to affect development and the endocrine system in vivo. In our previous study, altered behavior, indicative of potential neurotoxicity, was observed among rainbow trout alevins (day 14 posthatching) that were microinjected as embryos with a single environmentally relevant dose of 2,4-di-tert-butyl–6-(5-chloro-2H-benzotriazol-2-yl) phenol (UV-327). In the present follow-up study, we performed whole-transcriptome profiling (RNA sequencing) …

On The Injectivity Of The Shifted Funk–Radon Transform And Related Harmonic Analysis, Boris Rubin

Faculty Publications

Necessary and sufficient conditions are obtained for injectivity of the shifted Funk–Radon transform associated with k-dimensional totally geodesic submanifolds of the unit sphere Sⁿ in ℝⁿ⁺¹. This result generalizes the well known statement for the spherical means on Sⁿ and is formulated in terms of zeros of Jacobi polynomials. The relevant harmonic analysis is developed, including a new concept of induced Stiefel (or Grassmannian) harmonics, the Funk–Hecke type theorems, addition formula, and multipliers. Some perspectives and conjectures are discussed.

Ixpe Observation Of Pks 2155'304 Reveals The Most Highly Polarized Blazar, Pouya M. Kouch, Ioannis Liodakis, Riccardo Middei, Dawoon E. Kim, Fabrizio Tavecchio, Alan P. Marscher, Herman L. Marshall, Steven R. Ehlert, Laura Di Gesu, Svetlana G. Jorstad, Iván Agudo, Grzegorz M. Madejski, Roger W. Romani, Manel Errando, Elina Lindfors, Kari Nilsson, Ella Toppari, Stephen B. Potter, Ryo Imazawa, Mahito Sasada, Yasushi Fukazawa, Koji S. Kawabata, Makoto Uemura, Tsunefumi Mizuno, Tatsuya Nakaoka, Hiroshi Akitaya, Callum Mccall, Helen E. Jermak, Iain A. Steele, Ioannis Myserlis, Mark Gurwell, Garrett K. Keating, Ramprasad Rao

Faculty Publications

We report the X-ray polarization properties of the high-synchrotron-peaked (HSP) blazar PKS 2155'304 based on observations with the Imaging X-ray Polarimetry Explorer (IXPE). We observed the source between Oct 27 and Nov 7, 2023. We also conducted an extensive contemporaneous multiwavelength (MW) campaign. We find that during the first half (T1) of the IXPE pointing, the source exhibited the highest X-ray polarization degree detected for an HSP blazar thus far, (30.7 ± 2.0)%; this dropped to (15.3 ± 2.1)% during the second half (T2). The X-ray polarization angle remained stable during the IXPE pointing at 129.4 '±1.8 and 125.4 '±3.9 …

Reconstructive Evolutionary Morphology: Tracing The Historical Process Of Modifications Of Complex Systems Driven By Natural Selection Through Changing Ecological Conditions, Dominique G. Homberger

Faculty Publications

There is general consensus among evolutionary biologists that natural selection drives phenotypic modifications within populations over generational time. How to reconstruct this historical process, however, has been discussed mostly in theoretical terms, and recommendations and explanations on how to translate such theoretical insights into practice are needed. The present study aims at providing a theory-supported practical guide on how to reconstruct historical evolutionary processes by applying a morphology-centered approach through a series of interdependent steps of descriptive morphology, functional analysis, ecological observation, integration of paleoecological data, and evolutionary synthesis. Special attention is given to the development of tests regarding the …

The K-Profile Parameterization Augmented By Deep Neural Networks (Kpp_Dnn) In The General Ocean Turbulence Model (Gotm), Jianguo Yuan, Jun Hong Liang, Eric P. Chassignet, Olmo Zavala-Romero, Xiaoliang Wan, Meghan F. Cronin

Faculty Publications

This study utilizes Deep Neural Networks (DNN) to improve the K-Profile Parameterization (KPP) for the vertical mixing effects in the ocean's surface boundary layer turbulence. The deep neural networks were trained using 11-year turbulence-resolving solutions, obtained by running a large eddy simulation model for Ocean Station Papa, to predict the turbulence velocity scale coefficient and unresolved shear coefficient in the KPP. The DNN-augmented KPP schemes (KPP_DNN) have been implemented in the General Ocean Turbulence Model (GOTM). The KPP_DNN is stable for long-term integration and more efficient than existing variants of KPP schemes with wave effects. Three different KPP_DNN schemes, each …

First-Order Comprehensive Adjoint Sensitivity Analysis Methodology For Neural Ordinary Differential Equations: Mathematical Framework And Illustrative Application To The Nordheim–Fuchs Reactor Safety Model, Dan Gabriel Cacuci

Faculty Publications

This work introduces the mathematical framework of the novel “First-Order Comprehensive Adjoint Sensitivity Analysis Methodology for Neural Ordinary Differential Equations” (1st-CASAM-NODE) which yields exact expressions for the first-order sensitivities of NODE decoder responses to the NODE parameters, including encoder initial conditions, while enabling the most efficient computation of these sensitivities. The application of the 1st-CASAM-NODE is illustrated by using the Nordheim–Fuchs reactor dynamics/safety phenomenological model, which is representative of physical systems that would be modeled by NODE while admitting exact analytical solutions for all quantities of interest (hidden states, decoder outputs, sensitivities with respect to all parameters and initial conditions, …

Fake Base Station Detection And Link Routing Defense, Sourav Purification, Jinoh Kim, Jonghyun Kim, Sang-Yoon Chang

Faculty Publications

Fake base stations comprise a critical security issue in mobile networking. A fake base station exploits vulnerabilities in the broadcast message announcing a base station’s presence, which is called SIB1 in 4G LTE and 5G NR, to get user equipment to connect to the fake base station. Once connected, the fake base station can deprive the user of connectivity and access to the Internet/cloud. We discovered that a fake base station can disable the victim user equipment’s connectivity for an indefinite period of time, which we validated using our threat prototype against current 4G/5G practices. We designed and built a …

Application Of Surge Arrester In Limiting Voltage Stress At Direct Current Breaker, Mohammadamin Moghbeli, Shahab Mehraeen, Sudipta Sen

Faculty Publications

Hybrid DC circuit breakers combine mechanical switches with a redirecting current path, typically controlled by power electronic devices, to prevent arcing during switch contact separation. The authors’ past work includes a bipolar hybrid DC circuit breaker that effectively redirects the fault current and returns it to the source. This reduces arcing between the mechanical breaker’s contacts and prevents large voltage overshoots across them. However, the breaker’s performance declines as the upstream line inductance increases, causing overvoltage. This work introduces a modification to the originally proposed hybrid DC breaker to make it suitable to use anywhere along DC grid lines. By …

Shifting Baselines: Visualizing Climate Change In America’S National Parks, Lee Lines

Faculty Publications

No abstract provided.

Twisted Spatiotemporal Optical Vortex Beams In Dispersive Media, Milo W. Hyde Iv

Faculty Publications

We derive a closed-form expression for the mutual coherence function (MCF) of a twisted spatiotemporal optical vortex (STOV) beam after propagating a distance in a linear dispersive medium. A twisted STOV beam is a partially coherent optical field that possesses a coherent STOV and a stochastic twist coupling its space and time dimensions. These beams belong to a special class of space–time-coupled light fields that carry transverse (to the direction of propagation) orbital angular momentum, making them potentially useful in numerous applications including quantum optics, optical manipulation, and optical communications. After presenting the derivation, we validate our new general MCF …

Improvement Of Single-Crystal Structures Of Very Heavy Element Compounds By Refining Anomalous Dispersion Parameters, Florian Meurer, Gregory Morrison, Birgit Hischa, Hans Conrad Zur Loye, Christoph Hennig, Michael Bodensteiner

Faculty Publications

Refining the anomalous dispersion parameters of the four uranium compounds NaUF5, NaU2F9, Cs2(UO2)TiO4, and Cs2(UO2)Ti2O6 gave insights into the crystallographic model improvement of very heavy atoms. We found that the values for the dispersive and absorptive parts, f′ and f″, closely followed the X-ray absorption spectra on their L3, L2, and L1 edges. The obtained values are sensitive to the chemical environment at each crystallographically independent position. An incorrect treatment of the anomalous dispersion correction can lead to a wrong crystallographic model. The above-mentioned, already published structures were improved by this process. General guidelines were given for the crystal structure …

Open-Loop Wavefront Sensing In The Presence Of Speckle And Weak Scintillation, Derek J. Burrell, Mark F. Spencer, Ronald G. Driggers

Faculty Publications

In this paper, we show that speckle averaging helps to reduce the measurement error associated with a Shack–Hartmann wavefront sensor (SHWFS); however, this reduction is rendered ineffective with increasing beacon anisoplanatism. We do so operating in a weak-scintillation regime, where the SHWFS offers robust performance, and using in-plane translation of the illuminated rough surface to accomplish frame-to-frame speckle diversity. Understanding these trade-space limitations is critical when performing wavefront sensing with noncooperative, extended-source beacons.

Instructional Technology Tetrahedron And Network Visualization: Conceptualizing Online Teaching Through A Lens Of Reflective Noticing, Jinqing Liu, Orly Buchbinder

Faculty Publications

Online learning and teaching, accelerated by the global pandemic and rapid advancement of digital technology, require novel conceptual and analytical tools to understand better the evolving nature of online teaching. Drawing on the classical model of the instructional triangle and previous attempts to extend it, we propose the Instructional Technology Tetrahedron (ITT)—a conceptual framework that integrates technology into the instructional triangle to represent the role of technology, as a learning tool and a mediator between teachers, students, and content. Combining the ITT framework with network visualization strategies allowed for representing the intensity of interactions within the tetrahedron. We illustrate the …

Instructional Technology Tetrahedron And Network Visualization: Conceptualizing Online Teaching Through A Lens Of Reflective Noticing, Jinqing Liu, Orly Buchbinder

Faculty Publications

Online learning and teaching, accelerated by the global pandemic and rapid advancement of digital technology, require novel conceptual and analytical tools to understand better the evolving nature of online teaching. Drawing on the classical model of the instructional triangle and previous attempts to extend it, we propose the Instructional Technology Tetrahedron (ITT)—a conceptual framework that integrates technology into the instructional triangle to represent the role of technology, as a learning tool and a mediator between teachers, students, and content. Combining the ITT framework with network visualization strategies allowed for representing the intensity of interactions within the tetrahedron. We illustrate the …

Syntheses, Characterizations And Reactions Of Acene-2,3-Dicarbaldehydes, Glen Miller, Qian Liu

Faculty Publications

Here, we report improved syntheses, detailed characterizations and reactions of a series of acene-2,3- dicarbaldehydes including tetracene-2,3-dicarbaldehyde. DFT calculations corroborate and complement the experimental results. Tetracene-2,3-dicarbaldehyde and the benchmark organic semiconductor pentacene have isoelectronic p-systems and similar HOMO–LUMO gaps. Tetracene-2,3-dicarbaldehyde is soluble in a host of organic solvents (e.g., DMF, toluene, THF, chloroform, dichloromethane) and shows excellent photooxidative resistance in solution phases exposed to light and air. Further, it is readily sublimed from the solid-state without decomposition, and can be functionalized using different chemistries. We have demonstrated the utility of acene-2,3-dicarbaldehydes as reactants in the syntheses of novel diaryl-2,3-acenedimethanols and …

Effects Of Fluid Slip On Heat Transfer In The Thin Film Region In A Microchannel, Rama S. R. Gorla, John Brewer, Abdeel Roman

Faculty Publications

A theoretical study was undertaken to investigate the influence of interfacial slip on evaporation of a thin liquid film in a microfluidic channel. The disjoining pressure and the capillary force which drive the liquid flow at the liquid-vapor interface in thin film region are adopted. The evaporating thin film region is an extended meniscus beyond the apparent contact line at a liquid/solid interface. Thin film evaporation plays a key role in a highly efficient heat pipe. Slip length was found to affect the heat transfer in the microchannel by altering the thin film geometry.

Key Uncertainties And Modeling Needs For Managing Living Marine Resources In The Future Arctic Ocean, Julia G. Mason, Andrea Bryndum-Buchholz, Juliano Palacios-Abrantes, Renuka Badhe, Isabella Morgante, Daniele Bianchi, Julia L. Blanchard, Jason D. Everett, Cheryl S. Harrison, Ryan F. Heneghan, Camilla Novaglio, Colleen M. Petrik

Faculty Publications

Emerging fishing activity due to melting ice and poleward species distribution shifts in the rapidly-warming Arctic Ocean challenges transboundary management and requires proactive governance. A 2021 moratorium on commercial fishing in the Arctic high seas provides a 16-year runway for improved scientific understanding. Given substantial knowledge gaps, characterizing areas of highest uncertainty is a key first step. Marine ecosystem model ensembles that project future fish distributions could inform management of future Arctic fisheries, but Arctic-specific variation has not yet been examined for global ensembles. We use the Fisheries and Marine Ecosystem Intercomparison Project ensemble driven by two Earth System Models …

An Adaptive Nonlinear Least-Squares Finite Element Method For A Pucci Equation In Two Dimensions, Susanne C. Brenner, Li Yeng Sung, Zhiyu Tan

Faculty Publications

We present an adaptive nonlinear least-squares finite element method for a two dimensional Pucci equation. The efficiency of the method is demonstrated by a numerical experiment.

Anderson Localization For The Unitary Almost Mathieu Operator, Fan Yang

Faculty Publications

We prove Anderson localization for all Diophantine frequencies and all non-resonant phases for a model that arises from a 2D quantum walk model subject to an external magnetic field, also known as the unitary almost Mathieu operator. Our work provides the first localization results for all Diophantine frequencies in quasi-periodic quantum walk and CMV matrix setting. We also obtain sharp asymptotics of the localized eigenfunctions.

Review Of Fourth-Order Predictive Modeling And Illustrative Application To A Nuclear Reactor Benchmark. I. Typical High-Order Sensitivity And Uncertainty Analysis, Dan Gabriel Cacuci, Ruixian Fang

Faculty Publications

This work (in two parts) will review the recently developed predictive modeling methodology called “4th-BERRU-PM” and its applicability to nuclear energy systems as exemplified by an illustrative application to the Polyethylene-Reflected Plutonium (acronym: PERP) OECD/NEA reactor physics benchmark. The acronym 4th-BERRU-PM designates the “Fourth-Order Best-Estimate Results with Reduced Uncertainties Predictive Modeling” methodology, which uses the Maximum Entropy (MaxEnt) principle to incorporate fourth-order experimental and computational information, including fourth (and higher) order sensitivities of computed model responses to model parameters, while yielding best-estimate results with reduced uncertainties for the first fourth-order moments (mean values, covariance, skewness, and kurtosis) of the optimally …

Comparing Gas Composition From Fast Pyrolysis Of Live Foliage Measured In Bench-Scale And Fire-Scale Experiments, David R. Weise, Thomas H. Fletcher, Timothy J. Johnson, Wei Min Hao, Mark Dietenberger, Marko Princevac, Bret W. Butler, Sara S. Mcallister, Joseph J. O'Brien, E Louise Loudermilk, Roger D. Ottmar, Andrew T. Hudak, Akira Kato, Babak Shotorban, Shankar Mahalingham, Tanya L. Myers, Javier Palarea-Albaladejo, Stephen P. Baker

Faculty Publications

Background. Fire models have used pyrolysis data from oxidising and non-oxidising environments for flaming combustion. In wildland fires pyrolysis, flaming and smouldering combustion typically occur in an oxidising environment (the atmosphere). Aims. Using compositional data analysis methods, determine if the composition of pyrolysis gases measured in non-oxidising and ambient (oxidising) atmospheric conditions were similar. Methods. Permanent gases and tars were measured in a fuel-rich (non-oxidising) environment in a flat flame burner (FFB). Permanent and light hydrocarbon gases were measured for the same fuels heated by a fire flame in ambient atmospheric conditions (oxidising environment). Log-ratio balances of the measured gases …

A Generalization Of The Graham-Pollak Tree Theorem To Even-Order Steiner Distance, Joshua N. Cooper, Gabrielle Tauscheck

Faculty Publications

Graham and Pollak showed in 1971 that the determinant of a tree’s distance matrix depends only on its number of vertices, and, in particular, it is always nonzero. The Steiner distance of a collection of 𝑘 vertices in a graph is the fewest number of edges in any connected subgraph containing those vertices; for 𝑘 =2 , this reduces to the ordinary definition of graphical distance. Here we show that the hyperdeterminant of the 𝑘 th order Steiner distance hypermatrix is always nonzero if 𝑘 is even, extending their result beyond 𝑘 =2 . Previously, the authors showed that the …

Learning Nonlinear Dynamics In Synchronization Of Knowledge-Based Leader-Following Networks, Shimin Wang, Xiangyu Meng, Hongwei Zhang, Frank L. Lewis

Faculty Publications

Knowledge-based leader-following synchronization of heterogeneous nonlinear multi-agent systems is a challenging problem since the leader's dynamic information is unknown to any follower node. This paper proposes a learning-based fully distributed observer for a class of nonlinear leader systems, which can simultaneously learn the leader's dynamics and states. This class of leader dynamics is rather general and does not require a bounded Jacobian matrix. Based on this learning-based distributed observer, we further synthesize an adaptive distributed control law for solving the leader-following synchronization problem of multiple Euler–Lagrange systems subject to an uncertain nonlinear leader system. The results are illustrated by a …

Interpregnancy Interval And Adverse Perinatal Outcomes: A Within-Individual Comparative Method, Maria Sevoyan, Marco Geraci, Edward A. Frongillo, Jihong Liu, Nansi S. Boghossian

Faculty Publications

Background and Aim: Previously observed associations between interpregnancy interval (IPI) and perinatal outcomes using a between-individual method may be confounded by unmeasured maternal factors. This study aims to examine the association between IPI and adverse perinatal outcomes using within-individual comparative analyses. Methods: We studied 10,647 individuals from the National Institute of Child Health and Human Development Consecutive Pregnancies Study in Utah with ≥3 liveborn singleton pregnancies. We matched two IPIs per individual and used conditional logistic regression to examine the association between IPI and adverse perinatal outcomes, including preterm birth (PTB, < 37 weeks’ gestation), small-for-gestational-age (SGA, < 10th percentile of sex-specific birthweight for gestational age), low birthweight (LBW, < 2,500 g), and neonatal intensive care unit (NICU) admission. Point and 95% confidence interval (CI) estimates were adjusted for factors that vary across pregnancies within individuals. Results: CIs did not unequivocally support either an increase or a decrease in the odds of PTB (adjusted odds ratio [aOR]: 1.31, 95% CI: 0.87, 1.96), SGA (aOR: 0.81, 95% CI: 0.51, 1.28), LBW (aOR: 1.59, 95% CI: 0.90, 2.80), or NICU admission (aOR: 0.96, 95% CI: 0.66, 1.40) for an IPI < 6 months compared to 18–23-months IPI (reference), and neither did the CIs for the aOR of IPIs of 6–11 and 12–18 months compared to the reference. In contrast, an IPI ≥24 months was associated with increased odds of LBW (aOR: 1.66, 95% CI: 1.03, 2.66 for 24–29 months; aOR: 2.27, 95% CI: 1.21, 4.29 for 30–35 months; and aOR: 2.09, 95% CI: 1.17, 3.72 for ≥36 months). Conclusions: Using a within-individual comparative method, we did not find evidence that a short IPI compared to the recommended IPI of 18–23 months was associated with increased odds of PTB, SGA, LBW, and NICU admission. IPI ≥ 24 months was associated with increased odds of delivering an LBW infant.

Magnetic Sensor Compensation Utilizing Factor Graph Estimation, Frederic W. Lathrop, Clark N. Taylor, Aaron Nielsen

Faculty Publications

Recently, there has been significant interest in the ability to navigate without GPS using the magnetic anomaly field of the Earth (magnav). One of the key technical bottlenecks to achieving magnav is obtaining an accurate magnetic sensor calibration, taking into account own-ship and sensor effects. The Tolles-Lawson magnetic calibration method continues to be the industry standard and was developed when airborne magnetic survey aircraft were first employed over 70 years ago. In this paper, we present a magnetic calibration algorithm based on a factor graph optimization using inertial measurements as well as inputs from both a vector and scalar magnetometer. …

Impact Of Aureobasidium Species Strain Improvement On The Production Of The Polysaccharide Pullulan, Thomas P. West

Faculty Publications

This review explores the production of the fungal polysaccharide pullulan by mutants and natural isolates of Aureobasidium species using strain improvement. Pullulan is a neutral polysaccharide gum whose structure is a maltotriose-containing glucan. This polysaccharide gum has applications in the fields of food, pharmaceuticals, biomedical and wastewater treatment. The strain improvement of Aureobasidium species has focused on the pullulan production process, including the isolation of strains exhibiting reduced pigmentation, polysaccharide overproduction, the production of pullulan with variable molecular weight, and increased osmotolerant strains promoting pullulan production at high carbon source concentrations and pullulan production on hemicellulosic substrates. The majority of …