Digital Commons Network^™

Nonnative Species Richness And Dominance Reveal Differing Support For Invasion Theory At A Continental Extent, Lily M. Thompson, William K. Annis, Stephen R. Midway, Julian D. Olden, Brandon K. Peoples

Faculty Publications

Aim: Empirical tests of conceptual hypotheses describing species invasions often differ depending on the spatial scale (spatial resolution and extent of study area) at which they were conducted. Some of this disparity may arise from tradeoffs in data quality necessitating the use of different indices of community invadedness among scales. Local-scale studies typically use fine-resolution, descriptive measures of community invadedness (‘dominance’, the proportion nonnative individuals) at limited spatial extents, while macroscale studies often aggregate datasets to cover large spatial extents but use coarser spatial resolution and less descriptive indices (nonnative species richness). We investigated the consequences of using different indices …

Reef Fish Movement And Community Assemblages Associated With A Newly Deployed Artificial Reef, Jade M. Carver, Brett J. Falterman, Stephen R. Midway, Christian Walker, Creed C. Branham, Michael A. Dance

Faculty Publications

Artificial reefs provide critical habitat for fish in areas lacking benthic structure, yet our understanding of how artificial reefs function and develop is limited. Here, changes in fish community assemblages were monitored using baited remote underwater video (BRUV) surveys before and after a new artificial reef was deployed in the northern Gulf of Mexico. Movement of red snapper (Lutjanus campechanus) and gray snapper (Lutjanus griseus) between nearby oil and gas platforms (n = 3) and the new artificial reef was examined using acoustic telemetry, and residency was calculated for fish associated with both structure types. Fish community development at the …

Decoupling Of Bacterial Production And Respiration In The Surface Water Of The North Pacific Subtropical Gyre, Yuchen Zhang, Yibin Huang, Feipeng Xu, Shujie Cai, Yao Liu, Chao Xu, Lizhen Lin, Jixin Chen, Edward Allen Laws, Xin Liu, Bangqin Huang

Faculty Publications

Heterotrophic bacterial production and respiration, two important contributors to carbon cycling, play an important role in global biogeochemical cycles. However, recent research suggests that these two processes may be decoupled, and the underlying changes in community structure and their interactions remain unclear. In this study, two research expeditions to the North Pacific Subtropical Gyre (NPSG) during the summer and winter of 2020–2021 revealed seasonal shifts in bacterial metabolism and community structure in response to environmental factors. The findings indicated notable seasonal fluctuations in bacterial abundance and production in the surface waters. Both peaked in winter compared to summer. Alterations in …

On 2-Superirreducible Polynomials Over Finite Fields, J. W. Bober, L. Du, D. Fretwell, G. S. Kopp, T. D. Wooley

Faculty Publications

We investigate k-superirreducible polynomials, by which we mean irreducible polynomials that remain irreducible under any polynomial substitution of positive degree at most k. Let F be a finite field of characteristic p. We show that no 2-superirreducible polynomials exist in F[t] when p=2 and that no such polynomials of odd degree exist when p is odd. We address the remaining case in which p is odd and the polynomials have even degree by giving an explicit formula for the number of monic 2-superirreducible polynomials having even degree d. This formula is analogous to that given by Gauss for the number …

Direct Evidence For R-Process Nucleosynthesis In Delayed Mev Emission From The Sgr 1806-20 Magnetar Giant Flare, Anirudh Patel, Brian D. Metzger, Jakub Cehula, Eric Burns, Jared A. Goldberg, Todd A. Thompson

Faculty Publications

The origin of heavy elements synthesized through the rapid neutron capture process (r-process) has been an enduring mystery for over half a century. J. Cehula et al. recently showed that magnetar giant flares, among the brightest transients ever observed, can shock heat and eject neutron star crustal material at high velocity, achieving the requisite conditions for an r-process. A. Patel et al. confirmed an r-process in these ejecta using detailed nucleosynthesis calculations. Radioactive decay of the freshly synthesized nuclei releases a forest of gamma-ray lines, Doppler broadened by the high ejecta velocities v ≳ 0.1c into a quasi-continuous spectrum peaking …

Shielding Resources For Four Common Radiopharmaceuticals Utilized For Imaging And Therapy: Tc-99m, F-18, I-131, And Lu-177, Michael Oumano, Richard Wendt, James Botti, Nathan Busse, David Hintenlang, Stephanie Leon, Kevin Little, Melissa Martin, Richard Massoth, Kenneth Matthews, Rameshwar Prasad, Sharon White, Jessica Clements

Faculty Publications

Introduction: The use of radioactive materials in the United States has been tightly regulated by the Nuclear Regulatory Commission and other entities for many decades. In 2015, however, the Joint Commission began to require hospital-based nuclear medicine departments to conduct shielding designs and evaluations for radioactive material areas, mirroring established x-ray practices. NCRP Report No. 147 guides diagnostic medical x-ray shielding, but obviously cannot be used alone for nuclear medicine applications. The rising demand for theranostic nuclear medicine shielding evaluations particularly necessitates updated focused guidance, the aim of this report. Methods: Monte Carlo simulations were conducted using GATE software to …

Enhancing Compton Telescope Imaging With Maximum A Posteriori Estimation A Modified Richardson–Lucy Algorithm For The Compton Spectrometer And Imager, H. Yoneda, T. Siegert, I. Martinez-Castellanos, S. Gallego, C. Karwin, H. Bates, S. E. Boggs, C. Y. Huang, A. Joens, S. Matsumoto, S. Mittal, E. Neights, M. Negro, U. Oberlack, K. Okuma, S. Pike, J. Roberts, F. Rogers, Y. Sheng, T. Takahashi, A. Valluvan, Y. Watanabe, D. Hartmann, C. Kierans, J. Tomsick, A. Zoglauer

Faculty Publications

We present a modified Richardson-Lucy (RL) algorithm tailored for image reconstruction in MeV gamma-ray observations, focusing on its application to the upcoming Compton Spectrometer and Imager (COSI) mission. Our method addresses key challenges in MeV gamma-ray astronomy by incorporating Bayesian priors for sparseness and smoothness while optimizing background components simultaneously. We introduce a novel sparsity term suitable for Poisson-sampled data in addition to a smoothness prior, allowing for flexible reconstruction of both point sources and extended emission. The performance of the algorithm is evaluated using simulated three-month COSI observations of gamma-ray lines of ⁴⁴Ti (1.157 MeV), ²⁶Al (1.809 …

Algebraic Description Of The Triaxially To Axially Rotational Shape Phase Transition, Yu Zhang, Yu Xin Liu, Feng Pan, J. P. Draayer

Faculty Publications

Within the framework of the interacting boson model, we propose a novel algebraic scheme to describe spin-dependent structural evolutions in triaxial nuclei. Our analysis demonstrates that a triaxially to axially rotational shape phase transition can be induced by the high-order correction which is microscopically motivated by the pairing interaction on the γ-unstable rotation. This prescription is further applied to describe the structural evolutions along the yrast sequences of Ba132 and Xe130, providing an exemplary case for demonstrating a unified explanation of both low-energy collective structures and high-spin phenomena in O(6)-like nuclei.

The Frequency Shift And Q Of Disordered Superconducting Rf Cavities, Hikaru Ueki, Mehdi Zarea, J. A. Sauls

Faculty Publications

Niobium superconducting radio-frequency (SRF) cavities for high-energy accelerator applications have been greatly improved in terms of the quality factor Q by techniques such as Nitrogen doping. However, the mechanisms leading to improvement in Q are still not fully understood. Quite recently the SRF group at Fermilab measured anomalies in the frequency shift of N-doped SRF Niobium cavities near the transition temperature. Here we report our theoretical analysis of these results based on the microscopic theory of superconductivity that incorporates anisotropy of the superconducting gap and inhomogeneous disorder in the screening region of the SRF cavities. We are able to account …

Editorial Introduction: Bridging Policy Theory And Practice In Uncertain Times, Geoboo Song, Saba Siddiki, Holly L. Peterson, Melissa K. Merry, Ben Galloway, Camille Gilmore, Travis Wagher, Annette Nyoni

Faculty Publications

No abstract provided.

Evaluation Of Novel Jointless Engineered Cementitious Composite Ultrathin Whitetopping (Ecc-Utw) Overlay, Hassan Noorvand, Marwa Hassan, Tyson Rupnow, Ricardo Hungria

Publications

The present work corresponds to the development and the application of a cost-effective Engineered Cementitious Composites (ECC) mix design with the name M3-1.5%. Once the material was developed it was applied in the construction of a novel engineered cementitious composites ultrathin whitetopping (ECC-UTW) overlay. The overlay was constructed in May 2019 at the Pavement Research Facility (PRF) in Port Allen, Louisiana. The project was built on top of a distressed asphalt pavement corresponding to a previous project. During the construction, samples were gathered and subjected to testing after 28 days through means of compressive, uniaxial tension and flexural strength tests. …

Testing For Normality In Regression Models: Mistakes Abound (But May Not Matter), Stephen Midway, J. Wilson White

Faculty Publications

This study examines the misuse of normality tests in linear regression within ecology and biology, focusing on common misconceptions. A bibliometric review found that over 70% of ecology papers and 90% of biology papers incorrectly applied normality tests to raw data instead of model residuals. To assess the impact of this error, we simulated datasets with normal, interval, and skewed distributions across various sample and effect sizes. We compared statistical power between two approaches: testing the whole dataset for normality (incorrect) versus testing model residuals (correct) to determine whether to use a parametric (t-test) or nonparametric (Mann-Whitney U test) method. …

Advanced Manufacturing Of Multifunctional Shape Memory Polymer Composites And Self-Healing Systems, John B. Konlan

LSU Doctoral Dissertations

The need for multifunctional light weight structures for engineering applications is on the rise. Multifunctional composites are desired because of their ability to combine multiple functionalities into one structure. The advantages of a high strength-to-weight ratio of multifunctional composites make them desirable and suitable for use in energy-efficient applications. Shape-memory polymers (SMPs) have attracted interest over the past several decades because of their multifunctional nature. They have found use in many applications such as aerospace, satellites, automobiles, textiles, and biomedical devices, where lightweight and multifunctionality are key. The self-healing nature of most SMPs makes them suitable for use in lightweight …

Fishing For Solutions: Compensation For Bycatch Reduction In The Gulf Of Mexico Shrimp Fishery, Daniel W. Harris

LSU Master's Theses

Bycatch, unintentionally caught non-target species, harms the profitability of commercial fishing operations and leads to death and injury of hundreds of thousands of marine animals per year. In the Gulf of Mexico, commercial shrimpers are required to use a bycatch reduction device (BRD). Better BRDs are being tested to further reduce bycatch. Because their use will not be mandatory, it is important to measure shrimper willingness to voluntarily adopt this conservation technology to predict potential fleet participation. This study uses contingent valuation to elicit commercial shrimpers’ willingness to accept compensation for using these new devices.

We employ an incentivized payment …

Proteomic Comparison Of Canine Gallbladder Versus Hepatic Neuroendocrine Neoplasms, Nadia Richmond

LSU Master's Theses

Hepatobiliary neuroendocrine neoplasms (HBNENs) are uncommon tumors in people and dogs, and the limited understanding of their biologic behavior often poses a diagnostic and prognostic challenge in the clinical setting. Though only a low number of cases have been described in dogs, there is evidence to indicate that primary gallbladder NENs may carry a more favorable prognosis compared to primary hepatic NENs. The emergence of liquid chromatography-mass spectrometry (LC-MS) in proteomic analysis has permitted large-scale analysis of neoplastic proteomes, allowing for better understanding of tumor pathophysiology while simultaneously enabling the rapid identification of protein biomarkers. Previous work in our laboratory …

Promoting Social Inclusion Through Sport: A Case Study Of Uyghur Youth In China, Hongxin Li, Yunchao Bai, John Nauright

Faculty Publications

This study examines the role of sports as a means of promoting social inclusion among Uyghur youth in China, drawing upon social inclusion theory. Utilizing a qualitative case study methodology, we explored the perspectives of Uyghur youth athletes to gain insight into the challenges they face in achieving social inclusion without feeling “othered” or excluded. Data analysis followed an inductive grounded theory approach, identifying first‐order concepts, second‐order themes, and aggregate theoretical dimensions. Our findings reveal that social inclusion of Uyghur youth through sports participation is influenced by multiple factors, including language barriers, stereotypes, cultural differences, high expectations, and government policies. …

Unveiling The Interfacial Reconstruction Mechanism Enabling Stable Growth Of The Delafossite Pdcoo2 On Al2o3 And Laalo3, Anna Scheid, Tobias Heil, Y. Eren Suyolcu, Qi Song, Niklas Enderlein, Arnaud P. Nono Tchiomo, Prosper Ngabonziza, Philipp Hansmann, Darrell G. Schlom, Peter A. Van Aken

Faculty Publications

Delafossites, composed of noble metal (A⁺) and strongly correlated sublayers (BO2^-), form natural superlattices with highly anisotropic properties. These properties hold significant promise for various applications, but their exploitation hinges on the successful growth of high-quality thin films on suitable substrates. Unfortunately, the unique lattice geometry of delafossites presents a significant challenge to thin-film fabrication. Different delafossites grow differently, even when deposited on the same substrate, ranging from successful epitaxy to complete growth suppression. These variations often lack a clear correlation to obvious causes like lattice mismatch. Unidentified stabilization mechanisms appear to enable growth in certain …

Through The Looking Glass : Diversity Through The Eyes Of A Dress Form, Amara Copeland

LSU Master's Theses

This article aims to look into educational institutions and how they address diversity using curatorial displays. Does fashion and costume curation add to the seclusion of luxury? Looking into this correlation, this study aims to answer these next couple of questions. How does museum curation add to fashion social norms? Is it a subconscious or conscious decision when deciding on a mannequin or dress form? How do museum and fashion curations add to the exclusion of minorities in the world of luxury? What is costume luxury, and who do we say can obtain it?

This research aims to understand the …

Functional And Comparative Genomics Of The C.Sojina- Soybean Interaction, Alejandra Maria Vargas Oyuela

LSU Master's Theses

Frogeye leaf spot (FLS), caused by Cercospora sojina, is a significant foliar disease of soybean (Glycine max) and is responsible for substantial yield losses worldwide. While management strategies rely on host resistance and fungicide applications, the emergence of new virulent races and fungicide-resistant isolates necessitates a deeper understanding of C. sojina host interactions and genomic variability. Here, we employed comparative and functional genomic approaches to decipher the molecular mechanisms underlying the C. sojina-soybean interaction. A dual RNA sequencing approach was used to identify transcriptomic changes in G. max cultivars Blackhawk (susceptible) and Davis (resistant) across multiple …

A Natural Short Sleep Mutation Promotes Longevity Through Mitochondrial Respiration In Drosophila, Pritika Pandey

LSU Doctoral Dissertations

Aging is an irreversible process characterized by progressive physiological decline and an increased risk of metabolic disorders, cognitive impairment, cardiovascular diseases, and neurodegeneration. Disruptions to the circadian clock—whether due to genetic mutations or behavioral factors—accelerate aging and age-related pathologies, highlighting a strong link between circadian regulation and longevity. However, certain individuals harbor a dec2^P384R mutation, which enables natural short sleep without the detrimental effects of chronic sleep deprivation. This suggests that these individuals have evolved adaptations that activate pro-health pathways, allowing them to function optimally with reduced sleep. To investigate the genetic mechanisms underlying these changes, we developed a …

Evaluating Crop Response From Quizalofop And Fluridone Application In Louisiana Rice (Oryza Sativa L.), Wesley Carr

LSU Master's Theses

A field study was conducted at the H. Rouse Caffey Rice Research Station (RRS) in 2023 and 2024 to evaluate crop safety when quizalofop applications were made on ‘PVL03’ before and after overcast growing conditions. Factor A (main plot) consisted of no shade, shade for a period of 7 days prior to quizalofop application, or shade for a period of 7 days after quizalofop application. Factor B (sub plot) consisted of shade coverage representing simulated overcast weather at 0, 30, 60, or 90%. Factor C (sub-sub plot) consisted of no quizalofop, quizalofop at 120 g ha^-1, or quizalofop …

Effects Of Nitro-Substitution On The Spectroscopic And Self-Assembly Properties Of Bodipy Dyes, Caroline Gwaro, Caroline Ndung’U, Petia Bobadova-Parvanova, Dylan Goliber, Quynh Do, Ashley R. Walker, Evan Murders, Daniel Lamaster, Frank R. Fronczek, Jayne Garno, Maria Da Graça H. Vicente

Faculty Publications

A series of boron dipyrromethene (BODIPY) dyes were nitrated in high yields using nitronium tetrafluoroborate at positions 2, 3, and 2,6 of the BODIPY core. This method allows for the regioselective nitration of the pyrrolic positions under milder conditions than previously reported methods. The photophysical properties and electronic transitions of these BODIPYs were investigated by using UV-vis spectroscopy, fluorescence spectroscopy, and density-functional theory (DFT) calculations. The introduction of one nitro group dramatically increases the dipole moment of the molecule, induces marked blue shifts in the absorption and emission bands, decreases the molar absorptivity, and increases the Stokes shifts of the …

Impacts Of Climate Change On Cannibalism And Disease Transmission In The Fall Armyworm, Kale Rougeau

LSU Master's Theses

Climate change may alter host-pathogen dynamics in terrestrial ecosystems due to rising global temperatures and carbon dioxide levels. Here, we examined cannibalism and disease transmission using the fall armyworm (Spodoptera frugiperda), an invasive agricultural pest, and its species-specific lethal baculovirus, Spodoptera frugiperda multiple nucleopolyhedrovirus (SfMNPV), under various potential challenges of climate change. We used three temperature treatments (cooler, optimal, warmer) based on the fall armyworm’s thermal performance curve to simulate a changing climate and four artificial diets with various protein-to-carbohydrate ratios (low, equal, high, standard) to manipulate resource quality from altered carbon dioxide levels. We found that higher …

Advancing Aerial Survey Techniques For Non-Breeding Waterfowl Populations: A Comprehensive Review And Application In Northeastern Louisiana, Victoria L. Drake

LSU Master's Theses

Aerial surveys play a crucial role in monitoring North America's waterfowl populations and habitat conditions, and consistency across geographies and years allows biologists to track trends through time. The goal of this project was to redesign the northeastern portion of the Louisiana wintering waterfowl survey to align with statistically robust transect surveys conducted in neighboring states within the Mississippi Alluvial Valley. To identify the optimal sampling method, we evaluated three transect weighting schemes: stratified random (unweighted), stratified by watershed, and stratified by expert opinion. Approximately 10% of the total sampling area was randomly selected for each survey period, adhering to …

Global Ocean Bottom Temperature Observation Design: Observing System Simulation Experiments For Strategic Deployment Of Smart Subsea Cables, Karen E. Renninger-Rojas

LSU Master's Theses

Deep-ocean observations below 2000 meters remain limited, restricting our ability to model global ocean processes critical to climate prediction. This thesis evaluates the potential of SMART (Science Monitoring and Reliable Telecommunications) subsea cables to address these observational gaps by conducting Observing System Simulation Experiments (OSSEs) and adjoint sensitivity analyses using the MITgcm ocean model and ECCO outputs.

Vertical decorrelation analysis showed that temperature and salinity in key regions decouple from the upper ocean beyond 2000 m. Over 60% of the proposed SMART cable sites exhibited decorrelation depths exceeding Argo’s maximum sampling depth, highlighting their strategic value for deployment.

A comparison …

Animal-Assisted Therapy With Children In Hospitals And Schools: A Systematized Review, Tantine Kendig

LSU Master's Theses

It has been demonstrated that animals can offer humans significant health benefits. Animal-assisted therapy (AAT) is a growing form of therapy used in various settings to enhance the health of children, encompassing both physical and mental wellness. The challenges of hospitalization and the school environment have been shown to pose different challenges for children, such as an increase in anxiety, stress, depression, and others that have the potential to affect their mental, physical, emotional, and social well-being. This study aimed to assess the effectiveness of animal-assisted therapy, specifically dog-assisted therapy, on children in hospital and school settings by conducting a …

Multiparticle Quantum Plasmonics: Fundamentals And Applications, Mingyuan Hong

LSU Doctoral Dissertations

Quantum plasmonics explores the interaction between light and collective charge oscillations at metal-dielectric interfaces, enabling strong light confinement and enhanced quantum effects at the nanoscale. While traditional quantum optics has primarily focused on single-photon systems, an intermediate regime exists between classical and single-photon optics - multiparticle (or multiphoton) quantum optics. In this regime, classical light sources, when analyzed through techniques such as photon-number-resolving (PNR) detection and projective measurement, can reveal nontrivial quantum correlations. This thesis investigates how multiparticle quantum plasmonics harnesses these correlations to control quantum statistical properties, enhance coherence, and enable novel applications in quantum technologies.

In this thesis, …

Impacts Of Extreme Weather Conditions On Coastal Fisheries Near Bayou Teche, Louisiana From 2019–2023, Georgia C. Davis

LSU Master's Theses

The region of Southcentral Louisiana, particularly around Bayou Teche, thrives on its commercial and recreational fisheries. These fisheries are occasionally subject to events like extreme weather that cause sudden and unexpected losses (NOAA Fisheries, 2024a). Between 2019 and 2023, a series of extreme weather events impacted southcentral Louisiana near Bayou Teche. This series of extreme events includes Hurricane Barry (2019), Hurricane Laura (2020), Hurricane Delta (2020), Hurricane Zeta (2020), Hurricane Ida (2021), and a United States Drought Monitor (USDM) D4 drought (2023). This study analyzes the impacts of the extreme weather series on coastal fish observed species richness (SR) in …

Decadal To Millennial-Scale Morphodynamic Evolution Of Microtidal Marshes, Samuel Mason Zapp

LSU Doctoral Dissertations

Tidal marshes are susceptible to rapidly converting to open water due to their low elevations within the tidal frame. A continuous supply of externally supplied mineral sediment and in situ organic material production is necessary to offset elevation losses from relative sea level rise and erosion. Complex feedbacks between hydrodynamics, the erosion, transport, and deposition of sediment, and physical modification of the landscape by the establishment of intertidal vegetation govern the spatial and temporal patterns of elevation response. This dissertation focuses on modeling how these dynamics drive marsh landscape evolution in the past, present, and into the future under changing …

Neuronal Cftr: A Study Of Subcellular Localization And Interactions With Implications For A Role In Synaptic Transmission, Brandon J. Leviskas

LSU Doctoral Dissertations

Protein-protein interactions vary among cell types and the localization of these interactions help to define protein function. The function of cystic fibrosis transmembrane conductance regulator (CFTR) is well established in the context of epithelial tissue due to the debilitating effects of its mutations that cause the disease cystic fibrosis. While in neurons a role has been established in our lab for CFTR in the regulation of cytosolic Cl- in retinal amacrine cells (ACs). This research sets out to learn if CFTR has a synaptic role. Exploring this potential role, localization of CFTR was examined using fluorescent and immunogold labeled transmission …