Digital Commons Network^™

Value Creation In A Pedagogically-Focused Faculty Online Learning Community, Fred Goldberg, Edward Price, Mo Basir, Lawrence Escalada, Steve Maier, Steven Sahyun, Tamara D. Snyder, Liang Zeng

Faculty Publications

Faculty online learning communities (FOLCs) can help faculty effectively adopt and persist in using research-based curricula. This paper documents faculty perspectives on the value they gained from participating in a multi-year FOLC designed to help them implement an inquiry-based physical science curriculum. Personal value narratives were collected from 11 volunteer FOLC participants. In the narratives, participants responded to prompts regarding their initial reasons for participation, activities they engaged in, and values they gained, as well as how participation impacted their profession, social connections, professional practice, and ability to influence their world as teachers. Qualitative analysis shows that the values faculty …

Ion-Mediated Structural Discontinuities In Phospholipid Vesicles, Judith U. De Mel, Stefanie Klisch, Sudipta Gupta, Gerald J. Schneider

Faculty Publications

Despite intense research, methods for controlling soft matter’s spontaneous self-assembly into well-defined layers remain a significant challenge. We observed ion-induced structural discontinuities of phospholipid vesicles that can be exploited for controlled self-assembly of soft materials, using DOPC and NaCl as a model system. The observations were made for the 0.25 wt % lipid concentration. We used dynamic light scattering, zeta-potential measurement, cryo-electron microscopy, small-angle X-ray, and small-angle neutron scattering to understand the reason for the discontinuities. For salt concentrations below 8 mM, we observed a decrease in the liposome diameter with increased NaCl concentration. Above 8 mM, we measured a …

Effect Of Local Chain Stiffness On Oligomer Crystallization From A Melt, Pierre Kawak, Christopher Akiki, Douglas R. Tree

Faculty Publications

While the process by which a polymer crystal nucleates from the melt has been extensively studied via molecular simulation, differences in polymer models and simulated crystallization conditions have led to seemingly contradictory results. We make steps to resolve this controversy by computing low-temperature phase diagrams of oligomer melts using Wang-Landau Monte Carlo simulations. Two qualitatively different crystallization mechanisms are possible depending on the local bending stiffness potential. Polymers with a discrete bending potential crystallize via a single-step mechanism, whereas polymers with a continuous bending potential can crystallize via a two-step mechanism that includes an intermediate nematic phase. Other model differences …

On The Asymptotics Of Cubic Fields Ordered By General Invariants, Arul Shankar, Frank Thorne

Faculty Publications

In this article, we introduce a class of invariants of cubic fields termed “generalized discriminants”. We then obtain asymptotics for the families of cubic fields ordered by these invariants. In addition, we determine which of these families satisfy the Malle–Bhargava heuristic.

The Radiative And Geometric Properties Of Melting First-Year Landfast Sea Ice In The Arctic, Nathan J. M. Laxague, Christopher J. Zappa, Andrew R. Mahoney, John Goodwin, Cyrus Harris, Robert E. Schaeffer, Roswell Schaeffer, Sarah Betcher, Donna D W Hauser, Carson R. Witte, Jessica M. Lindsay, Ajit Subramaniam, Kate E. Turner, Alex Whiting

Faculty Publications

In polar regions, sea ice is a crucial mediator of the interaction between Earth's atmosphere and oceans. Its formation and breakup is intimately connected with large-scale climatic processes, local weather patterns, and the use of sea ice in coastal Arctic regions by Indigenous people. In order to investigate the physical phenomena at the heart of this process, a set of targeted, intensive observations were made over spring sea ice melt and breakup in Kotzebue Sound, Alaska. These observations were planned and executed through a collaborative effort in which an Indigenous Elder advisory council from Kotzebue and scientists participated in co-production …

Entanglement From Rotating Black Holes In Thermal Baths, Ivan Agullo, Anthony J. Brady, Adrià Delhom, Dimitrios Kranas

Faculty Publications

We extend previous efforts to quantify the entanglement generated in Hawking's evaporation process by including rotation and thermal environments (e.g. the cosmic microwave background). Both extensions are needed to describe real black holes in our Universe. Leveraging techniques from Gaussian quantum information, we find that the black hole's ergoregion is an active source of quantum entanglement and that thermal environments drastically degrade entanglement generation. Our predictions are suitable to be tested in the lab using analog platforms and also provide tools to assess the fate of quantum information for black holes in more generic settings.

Exploring The Role Of Disciplinary Knowledge In Students' Covariational Reasoning During Graphical Interpretation, Nigar Altindis, Kathleen A. Bowe, Brock Couch, Christopher F. Bauer, Melissa L. Aikens

Faculty Publications

Background: This study investigates undergraduate STEM students’ interpretation of quantities and quantitative relationships on graphical representations in biology (population growth) and chemistry (titration) contexts. Interviews (n = 15) were conducted to explore the interplay between students’ covariational reasoning skills and their use of disciplinary knowledge to form mental images during graphical interpretation.

Results: Our findings suggest that disciplinary knowledge plays an important role in students’ ability to interpret scientific graphs. Interviews revealed that using disciplinary knowledge to form mental images of represented quantities may enhance students’ covariational reasoning abilities, while lacking it may hinder more sophisticated covariational reasoning. Detailed descriptions …

Culturally Relevant Music Remedies For At-Risk Students, José Valentino Ruiz-Resto, Chris Shelton

Faculty Publications

This article presents a comprehensive review of the existing literature on the impact of social media on mental health. With the rapid growth and widespread adoption of social media platforms, concerns regarding their potential influence on individuals' psychological well-being have emerged. Drawing from a diverse range of studies, this review explores the various dimensions through which social media can affect mental health, including self-esteem, body image, loneliness, depression, anxiety, and addictive behaviors. The findings reveal both positive and negative outcomes, highlighting the complex relationship between social media use and mental health. Additionally, this article discusses the underlying mechanisms and potential …

Childhood Sexual Abuse And Compulsive Sexual Behavior Among Men Who Have Sex With Men Newly Diagnosed With Hiv, Monique J. Brown, Medinat Omobola Osinubi, Daniel Amoatika, Mohammad Rifat Haider, Sally Kirklewski, Patrick Wilson, Nathan B. Hansen

Faculty Publications

Childhood sexual abuse (CSA) continues to be a public health challenge. The prevalence of experiencing CSA is higher among men who have sex with men (MSM) than the general population. CSA has been linked to compulsive sexual behavior (CSB) among varying populations but has not been examined among MSM who were newly diagnosed with HIV. Therefore, the aims of this study were to assess the direct association between CSA and CSB among newly diagnosed MSM living with HIV, and to identify the potential mediating roles of depressive symptoms and emotion regulation in the association between CSA and CSB. The study …

Mdf-Dta: A Multi-Dimensional Fusion Approach For Drug-Target Binding Affinity Prediction, Amit Ranjan, Adam Bess, Chris Alvin, Supratik Mukhopadhyay

Faculty Publications

Drug-target affinity (DTA) prediction is an important task in the early stages of drug discovery. Traditional biological approaches are time-consuming, effort-consuming, and resource-consuming due to the large size of genomic and chemical spaces. Computational approaches using machine learning have emerged to narrow down the drug candidate search space. However, most of these prediction models focus on single feature encoding of drugs and targets, ignoring the importance of integrating different dimensions of these features. We propose a deep learning-based approach called Multi-Dimensional Fusion for Drug Target Affinity Prediction (MDF-DTA) incorporating different dimensional features. Our model fuses 1D, 2D, and 3D representations …

Strength Measurement Of The E_Α^Lab = 830 Kev Resonance In The Ne 22 ( Α , N ) Mg 25 Reaction Using A Stilbene Detector, Shahina S., R. J. Deboer, J. Gorres, R. Fang, Michael T. Febbraro, R. Kelmar, M. Matney, K. Manukyan, J. T. Nattress, E. Robles, T. J. Rutland, T. T. King, A. Sanchez, R. S. Sidhu, E. Stech, M. Wiescher

Faculty Publications

The interplay between the ²²Ne (��,��)²⁶Mg reaction and the competing ²²Ne(��,��)²⁵Mg reaction determines the efficiency of the latter as a neutron source at the temperatures of stellar helium burning. In both cases, the rates are dominated by the ��-cluster resonance at 830 keV. This resonance plays a particularly important role in determining the strength of the neutron flux for both the weak and main �� process as well as the �� process. Recent experimental studies based on transfer reactions suggest that the neutron and ��-ray strengths for this resonance are approximately equal. In this …

Hd-Tdcs Over Left Supplementary Motor Area Differentially Modulated Neural Correlates Of Motor Planning For Speech Vs. Limb Movement, Fatemeh Tabari, Celeste Patron, Hope Cryer, Karim Johari

Faculty Publications

The supplementary motor area (SMA) is implicated in planning, execution, and control of speech production and limb movement. The SMA is among putative generators of pre-movement EEG activity which is thought to be neural markers of motor planning. In neurological conditions such as Parkinson's disease, abnormal pre-movement neural activity within the SMA has been reported during speech production and limb movement. Therefore, this region can be a potential target for non-invasive brain stimulation for both speech and limb movement. The present study took an initial step in examining the application of high-definition transcranial direct current stimulation (HD-tDCS) over the left …

Application Of Near-Infrared Spectroscopy For Hay Evaluation At Different Degrees Of Sample Preparation, Eun Chan Jeong, Kun Jun Han, Farhad Ahmadi, Yan Fen Li, Li Li Wang, Young Sang Yu, Jong Geun Kim

Faculty Publications

Objective: A study was conducted to quantify the performance differences of the near-infrared spectroscopy (NIRS) calibration models developed with different degrees of hay sample preparations. Methods: A total of 227 imported alfalfa (Medicago sativa L.) and another 360 imported timothy (Phleum pratense L.) hay samples were used to develop calibration models for nutrient value parameters such as moisture, neutral detergent fiber, acid detergent fiber, crude protein, and in vitro dry matter digestibility. Spectral data of hay samples prepared by milling into 1-mm particle size or unground were separately regressed against the wet chemistry results of the abovementioned parameters. Results: The …

Secondary Production And Biomass In Mussel Assemblages Relate To Species Richness And Stream Size But Not Life History, Jonathan W. Lopez, Carla L. Atkinson, Angela K. Burrow, Garrett W. Hopper, Wendell R. Haag

Faculty Publications

Increases in species richness with habitat area (species–area relationship, or SAR) and increases in ecosystem function with species richness (biodiversity–ecosystem functioning, or BEF) are widely studied ecological patterns. Incorporating functional trait analysis into assemblage datasets may help clarify interpretations of SAR and BEF relationships in natural ecological systems. For example, life history theory can be used to make predictions about what species are most important in generating ecosystem function given a certain set of environmental conditions. We used quantitative assemblage data for freshwater mussels at nine sites in western Alabama, USA, to test for SAR and BEF relationships. At each …

Grb 180128a: A Second Magnetar Giant Flare Candidate From The Sculptor Galaxy, Aaron C. Trigg, Eric Burns, Oliver J. Roberts, Michela Negro, Dmitry S. Svinkin, Matthew G. Baring, Zorawar Wadiasingh, Nelson L. Christensen, Igor Andreoni, Michael S. Briggs, Niccolò Di Lalla, Dmitry D. Frederiks, Vladimir M. Lipunov, Nicola Omodei, Anna V. Ridnaia, Peter Veres, Alexandra L. Lysenko

Faculty Publications

Magnetars are slowly rotating neutron stars that possess the strongest magnetic fields known in the cosmos (10¹⁴-10¹⁵ G). They display a range of transient high-energy electromagnetic activity. The brightest and most energetic of these events are the gamma-ray bursts (GRBs) known as magnetar giant flares (MGFs), with isotropic energies Eiso10⁴⁴10⁴⁶ erg. Only seven MGF detections have been made to date: three unambiguous events occurred in our Galaxy and the Magellanic Clouds, and the other four MGF candidates are associated with nearby star-forming galaxies. As all seven identified MGFs are bright at Earth, additional weaker …

Modeling Interactions Of Planting Date And Phenology In Louisiana Rice Under Current And Future Climate Conditions, Sajad Jamshidi, Teresa Murgia, Ana G. Morales-Ona, Tommaso Cerioli, Adam N. Famoso, Davide Cammarano, Diane R. Wang

Faculty Publications

The performance of novel genetic combinations under untested environmental scenarios and management practices can be virtually examined using process-based crop models. Indeed, there has been a long-standing interest in the crop modeling community to expand the utility of process-based models to broader germplasm panels (e.g., breeding lines or diversity panels). Yet, there is often a misalignment between data needed to parameterize process-based crop models and data routinely collected by breeding programs. To address this gap, we leverage a dataset from a long-term trial on advanced experimental lines and released varieties from the Louisiana rice breeding program to calibrate and evaluate …

Snapshots Of Coastal Ecology Using Multiproxy Analysis Reveals Insights Into The Preservation Of Swamp And Marsh Environments Since The Late Pleistocene, Kendall Fontenot, Kristine L. Delong, Brian A. Schubert, Sophie Warny, Davin J. Wallace, Carrie M. Miller, Erin Culver-Miller, Michael J. Polito, Carl A. Reese, Kathryn Garretson, Kehui Xu, Grant L. Harley, Jeffrey Obelcz, Kelli L. Moran, Julian Traphagan, Douglas Jones, Alicia Caporaso

Faculty Publications

The southeastern United States Coastal Plain ecosystem contains baldcypress (Taxodium distichum) swamps and grass-dominated marshes. These ecosystems also occurred on the exposed continental shelf during lower sea levels but are rarely preserved due to the mechanically erosive nature of transgression and regression. Two presently marine sites on the northeastern Gulf of Mexico's continental shelf contain well-preserved woody terrestrial sediments that were the subject of previous studies. This study continues the investigation using geochemical (δ13C, δ15N, δ34S) and palynological characteristics of these formerly terrestrial sediments to determine if swamps and/or marshes existed at the time of deposition. The first site is …

A Simple Approach To Dealing With Partial Contestation, Ali Kagalwala, Thiago M.Q. Moreira, Guy D. Whitten

Faculty Publications

Objective: We propose a simple approach to dealing with partial contestation in models of multiparty elections. Methods: Our proposed approach is to add a tiny value to the vote share of parties that do not contest a district and then to include dummy variables identifying those districts in which parties do not compete. We can then estimate a single system of equations using a seemingly unrelated regression (SUR) approach and Aitchison's log-ratio transformation. In our SUR system, we interact the dummy variable for a party that partially contested districts with other predictors in the equation that uses the share of …

The Expression Of Mantle Seismic Anisotropy In The Global Seismic Wavefield, Jonathan Wolf, Maureen D. Long, Daniel A. Frost, Tarje Nissen-Meyer

Faculty Publications

The dependence of seismic wave speeds on propagation or polarization direction, called seismic anisotropy, is a relatively direct indicator of mantle deformation and flow. Mantle seismic anisotropy is often inferred from measurements of shear-wave splitting. A number of standard techniques to measure shear-wave splitting have been applied globally; for example, *KS splitting is often used to measure upper mantle anisotropy. In order to obtain robust constraints on anisotropic geometry, it is necessary to sample seismic anisotropy from different directions, ideally using different seismic phases with different incidence angles. However, many standard analysis techniques can only be applied for certain epicentral …

Persistent Behavior In Solar Energetic Particle Time Series, N V. Sarlis, G Livadiotis, D J. Mccomas, M E. Cuesta, L Y. Khoo, C M S Cohen, D G. Mitchell, Nathan A. Schwadron

Faculty Publications

We investigate the long-term persistence of solar energetic particle (SEP) time series by means of four different methods: Hurst rescaled range R/S analysis, detrended fluctuation analysis, centered moving average analysis, and the fluctuation of natural time under the time reversal method. For these analyses, we use data sets from the Integrated Science Investigation of the Sun instrument suite on board NASA's Parker Solar Probe. Background systematic noise is modeled using cross-correlation analysis between different SEP energy channels and subtracted from the original data. The use of these four methods for deriving the time-series persistence allows us to (i) differentiate between …

Functional Multivariable Logistic Regression With An Application To Hiv Viral Suppression Prediction, Siyuan Guo, Jiajia Zhang Ph.D., Yichao Wu, Alexander C. Mclain Ph.D., James W. Hardin, Bankole Olatosi Ph.D., Xiaoming Li Ph.D.

Faculty Publications

Motivated by improving the prediction of the human immunodeficiency virus (HIV) suppression status using electronic health records (EHR) data, we propose a functional multivariable logistic regression model, which accounts for the longitudinal binary process and continuous process simultaneously. Specifically, the longitudinal measurements for either binary or continuous variables are modeled by functional principal components analysis, and their corresponding functional principal component scores are used to build a logistic regression model for prediction. The longitudinal binary data are linked to underlying Gaussian processes. The estimation is done using penalized spline for the longitudinal continuous and binary data. Group-lasso is used to …

Persistent Behavior In Solar Energetic Particle Time Series, N V. Sarlis, G Livadiotis, D J. Mccomas, M E. Cuesta, L Y. Khoo, C M S Cohen, D G. Mitchell, Nathan A. Schwadron

Faculty Publications

We investigate the long-term persistence of solar energetic particle (SEP) time series by means of four different methods: Hurst rescaled range R/S analysis, detrended fluctuation analysis, centered moving average analysis, and the fluctuation of natural time under the time reversal method. For these analyses, we use data sets from the Integrated Science Investigation of the Sun instrument suite on board NASA's Parker Solar Probe. Background systematic noise is modeled using cross-correlation analysis between different SEP energy channels and subtracted from the original data. The use of these four methods for deriving the time-series persistence allows us to (i) differentiate between …

Characteristics Of Pyrolysis Products Of California Chaparral And Their Potential Effect On Wildland Fires, Mahsa Alizadeh, David R. Weise, Thomas H. Fletcher

Faculty Publications

The aim of this study was to investigate the pyrolysis of selected California foliage and estimate the energy content of the released volatiles to show the significance of the pyrolysis of foliage and its role during wildland fires. While the majority of the volatiles released during the pyrolysis of foliage later combust and promote fire propagation, studies on the energy released from combustion of these compounds are scarce. Samples of chamise (Adenostoma fasciculatum), Eastwood’s manzanita (Arctostaphylos glandulosa), scrub oak (Quercus berberidifolia), hoaryleaf ceanothus (Ceanothus crassifolius), all native to southern California, and sparkleberry …

Derivative Propagation Through Vortex Particle Method Simulation, Eric Green, Andrew Ning

Faculty Publications

Automatic differentiation (AD) is a powerful tool for evaluating numerical derivatives. In particular, reverse-mode AD provides numerical gradients in a way that is insensitive to the number of input variables. This makes reverse-mode AD well-suited for solving large optimization problems. However, reverse-mode AD has a particularly large associated memory cost because most intermediate values in operations need to be cached. This is problematic for large problems such as aerodynamics simulations, though, since the memory requirements can quickly become impractical. The solution implemented in this work is to provide analytic pullback expressions for functions for which many of the intermediate values …

Trajectory Optimization Of Evtol And Conventional Aircraft: A Comparative Analysis Of Vortex Particle Method And Vortex Lattice + Blade Element Momentum Theory, Andrew Tagg, Ryan Anderson, Cibin Joseph, Andrew Ning

Faculty Publications

Trajectory optimization of aircraft transition maneuvers can significantly influence the design of these systems, particularly when making decisions about aircraft geometry, propulsion sizing, and control system design. This paper presents the trajectory optimization of air vehicles including electric vertical takeoff and landing (eVTOL) as well as conventional aircraft. The study evaluates the influence of fidelity in trajectory design by comparing the use of two aerodynamic methods in the context of trajectory optimization. The mid-fidelity method utilizes a vortex lattice method (VLM) to model lifting surfaces while employing blade element momentum theory (BEMT) to model rudimentary rotor-wing interactions. The high-fidelity approach …

An Integrated Space Test Lexicon: A Taxonomy For The Integrated Test And Evaluation Of Space Systems, Stephen K. Tullino, Andrew S. Keys, Robert A. Bettinger, Amy M. Cox, David R. Jacques

Faculty Publications

The proposed Integrated Space Test Lexicon is intended to amalgamate the numerous definitions of integrated (IT or IT&E), development test (DT or DT&E), and operational test (OT or OT&E) into unified, service-wide definitions, aligned with the Space Test Enterprise Vision. Refining such definitions will help distill the core characteristics of these fundamental test types to first identify space system activities composing what is traditionally known as DT and OT, then to provide a means of how these activities fit into the IT paradigm and support space system development. In forging a common understanding of how DT and OT support space …

Solving Unsteady Potential Flow Problems In O(N) Time, Ryan Anderson, Andrew Ning

Faculty Publications

Design of vertical takeoff and landing aircraft is challenging in part due to significant aerodynamic interactions between rotors and wings. Computational models can aid in their design, but are computationally expensive. 3-D panel methods coupled with vortex particle wakes offer an attractive solution, but solving for the panel strengths scales poorly for large problems. Multigrid methods, such as Krylov subspace methods in conjunction with the fast multipole method (FMM), have been demonstrated to reduce the scaling to O(𝑁). We explore the performance and limitations of the Krylov-FMM method, traditional matrix-powered GMRES, LU decomposition, and a novel O(𝑁) multigrid approach to …

Children’S Reading Of Visuals In Informational Picturebooks And Biographies, Sunah Chung

Faculty Publications

Visuals in picturebooks play an important role in supporting children’s reading comprehension and literacy development. This qualitative case study analyzes three American families’ shared reading practices at home by analyzing their online surveys for family literacy environments, reading logs for a month, mother interviews, and video observation of their shared reading at home. The analysis of the collected data categorizes children’s responses to visuals into three major themes: reflecting personal preferences and thoughts on visuals, interpreting visuals based on prior knowledge, and misreading visuals that interfere with understanding content. The discussion focuses on the roles of visuals in informational picturebooks …

The Fate Of Fixed Nitrogen In Santa Barbara Basin Sediments During Seasonal Anoxia, Xuefeng Peng, David J. Yousavich, Annie Bourbonnais, Frank Wenzhöfer, Felix Janssen, Tina Treude, David L. Valentine

Faculty Publications

Despite long-standing interest in the biogeochemistry of the Santa Barbara Basin (SBB), there are no direct rate measurements of different nitrogen transformation processes. We investigated benthic nitrogen cycling using in situ incubations with ¹⁵NO ₃̅  addition and quantified the rates of total nitrate (NO ₃̅) uptake, denitrification, anaerobic ammonia oxidation (anammox), N₂O production, and dissimilatory nitrate reduction to ammonia (DNRA). Denitrification was the dominant NO ₃̅ reduction process, while anammox contributed 0 %–27 % to total NO ₃̅ reduction. DNRA accounted for less than half of NO ₃̅ reduction except at the …

Incorporating Oxygen Isotopes Of Oxidized Reactive Nitrogen In The Regional Atmospheric Chemistry Mechanism, Version 2 (Icoin-Racm2), Wendell W. Walter, Masayuki Takeuchi, Nga L. Ng, Meredith G. Hastings

Faculty Publications

The oxygen isotope anomaly (Δ¹⁷O = δ¹⁷O − 0.52 × δ¹⁸O > 0) has proven to be a robust tool for probing photochemical cycling and atmospheric formation pathways of oxidized reactive nitrogen (NO_y). Several studies have developed modeling techniques to implicitly model Δ¹⁷O of NO_y molecules based on numerous assumptions that may not always be valid. Thus, these models may be oversimplified and limit our ability to compare model Δ¹⁷O values of NO_y with observations. In this work, we introduce a novel method for explicitly tracking Δ …