Digital Commons Network^™

Heavy-Element Production In A Compact Object Merger Observed By Jwst, Andrew J. Levan, Benjamin P. Gompertz, Om Sharan Salafia, Mattia Bulla, Eric Burns, Kenta Hotokezaka, Luca Izzo, Gavin P. Lamb, Daniele B. Malesani, Samantha R. Oates, Maria Edvige Ravasio, Alicia Rouco Escorial, Benjamin Schneider, Nikhil Sarin, Steve Schulze, Nial R. Tanvir, Kendall Ackley, Gemma Anderson, Gabriel B. Brammer, Lise Christensen, Vikram S. Dhillon, Phil A. Evans, Michael Fausnaugh, Wen Fai Fong, Andrew S. Fruchter, Chris Fryer, Johan P.U. Fynbo, Nicola Gaspari, Kasper E. Heintz, Jens Hjorth, Jamie A. Kennea, Mark R. Kennedy, Tanmoy Laskar

Faculty Publications

The mergers of binary compact objects such as neutron stars and black holes are of central interest to several areas of astrophysics, including as the progenitors of gamma-ray bursts (GRBs)¹, sources of high-frequency gravitational waves (GWs)² and likely production sites for heavy-element nucleosynthesis by means of rapid neutron capture (the r-process)³. Here we present observations of the exceptionally bright GRB 230307A. We show that GRB 230307A belongs to the class of long-duration GRBs associated with compact object mergers^4–6 and contains a kilonova similar to AT2017gfo, associated with the GW merger GW170817 (refs. ^7–12). …

59th Student Senate Week 4 Meeting Minutes, Zoe Joubert

Student Senate Meeting Minutes

No abstract provided.

59th Student Senate Week 1 Meeting Minutes, Zoe Joubert

Student Senate Meeting Minutes

No abstract provided.

The Impact Of American Kitchen Time-Use On Urban Design And Planning: A Case Study Of Baton Rouge, Louisiana, Farshid Torabian

LSU Doctoral Dissertations

Over the past century, the global environment has undergone significant changes, characterized by rising temperatures and a sharp increase in greenhouse gas emissions. Parallel to these environmental shifts, the U.S. has witnessed a tripling in energy demands, underscoring the pivotal role of household consumption in the nation's carbon footprint. Within this context, the kitchen, an integral component of the American home, becomes a focal point. Given that Americans predominantly spend their time indoors, it is imperative to understand the dynamics of kitchen usage and its broader implications on energy consumption and environmental impact. To delve into this complex interplay, this …

Distinguishing Molecular Mechanical Action From Photothermal And Photodynamic Behavior, Jacob L. Beckham, Thomas S. Bradford, Ciceron Ayala-Orozco, Ana L. Santos, Dallin Arnold, Alexis R. Van Venrooy, Víctor García-López, Robert Pal, James M. Tour

Faculty Publications

Molecular motors (MM) are molecular machines, or nanomachines, that rotate unidirectionally upon photostimulation and perform mechanical work on their environment. In the last several years, it has been shown that the photomechanical action of MM can be used to permeabilize lipid bilayers, thereby killing cancer cells and pathogenic microorganisms and controlling cell signaling. The work contributes to a growing acknowledgement that the molecular actuation characteristic of these systems is useful for various applications in biology. However, the mechanical effects of molecular motion on biological materials are difficult to disentangle from photodynamic and photothermal action, which are also present when a …

59th Student Senate Week 3 Meeting Minutes, Zoe Joubert

Student Senate Meeting Minutes

No abstract provided.

Block-Based Programming For Two-Armed Robots: A Comparative Study, Felipe Fronchetti, Chandler Barfield, Nico Ritschel, Gabriella Chang, Logan Schorr, Rodrigo Spinola, Reid Holmes, David C. Shepherd

Faculty Publications

Programming industrial robots is difficult and expensive. Although recent work has made substantial progress in making it accessible to a wider range of users, it is often limited to simple programs and its usability remains untested in practice. In this article, we introduce Duplo, a block-based programming environment that allows end-users to program two-armed robots and solve tasks that require coordination. Duplo positions the program for each arm side-by-side, using the spatial relationship between blocks from each program to represent parallelism in a way that end-users can easily understand. This design was proposed by previous work, but not implemented or …

Seasonal, Spatial, And Water Level Predictors Of Angler Catch And Effort Within Texas Black Bass Reservoir Fisheries, David R. Smith, J. Warren Schlechte, Randall A. Myers, Michael A. Dance, Jacob D. Norman, Mitchell T. Nisbet

Faculty Publications

Objective: We sought to identify seasonal, spatial, and water level predictors of black bass angler catch rates and effort densities (i.e., angler-hours/ha) within Texas reservoirs. Methods: We tested for predictors of effort density and catch rate while building generalized additive models with responses derived from a long-term creel data set and explanatory variables derived from the season of the creel survey, geoposition of the reservoir, and water level data obtained from the Texas Water Development Board. Result: Season significantly affected models, with strong positive effects on catch rates during the spring and fall and strong positive effects on effort densities …

Effector-Triggered Susceptibility By The Rice Blast Fungus Magnaporthe Oryzae, Ely Oliveira-Garcia, Xia Yan, Miriam Oses-Ruiz, Samuel De Paula, Nicholas J. Talbot

Faculty Publications

Rice blast, the most destructive disease of cultivated rice world-wide, is caused by the filamentous fungus Magnaporthe oryzae. To cause disease in plants, M. oryzae secretes a diverse range of effector proteins to suppress plant defense responses, modulate cellular processes, and support pathogen growth. Some effectors can be secreted by appressoria even before host penetration, while others accumulate in the apoplast, or enter living plant cells where they target specific plant subcellular compartments. During plant infection, the blast fungus induces the formation of a specialized plant structure known as the biotrophic interfacial complex (BIC), which appears to be crucial for …

Residual-Based Error Corrector Operator To Enhance Accuracy And Reliability Of Neural Operator Surrogates Of Nonlinear Variational Boundary-Value Problems, Prashant K. Jha

Faculty Publications

This work focuses on developing methods for approximating the solution operators of a class of parametric partial differential equations via neural operators. Neural operators have several challenges, including the issue of generating appropriate training data, cost-accuracy trade-offs, and nontrivial hyperparameter tuning. The unpredictability of the accuracy of neural operators impacts their applications in downstream problems of inference, optimization, and control. A framework based on the linear variational problem that gives the correction to the prediction furnished by neural operators is considered based on earlier work in JCP 486 (2023) 112104. The operator, called Residual-based Error Corrector Operator or simply Corrector …

Embryonic Exposure To The Benzotriazole Ultraviolet Stabilizer 2-(2h-Benzotriazol-2-Yl)-4-Methylphenol Decreases Fertility Of Adult Zebrafish (Danio Rerio), Yamin Raza, Emily Mertens, Lauren Zink, Zhe Lu, Jon A. Doering, Steve Wiseman

Faculty Publications

Benzotriazole ultraviolet stabilizers (BUVSs) are emerging contaminants of concern. They are added to a variety of products, including building materials, personal care products, paints, and plastics, to prevent degradation caused by ultraviolet (UV) light. Despite widespread occurrence in aquatic environments, little is known regarding the effects of BUVSs on aquatic organisms. The aim of the present study was to characterize the effects of exposure to 2-(2H-benzotriazol-2-yl)-4-methylphenol (UV-P) on the reproductive success of zebrafish (Danio rerio) following embryonic exposure. Embryos were exposed, by use of microinjection, to UV-P at < 1.5 (control), 2.77, and 24.25 ng/g egg, and reared until sexual maturity, when reproductive performance was assessed, following which molecular and biochemical endpoints were analyzed. Exposure to UV-P did not have a significant effect on fecundity. However, there was a significant effect on fertilization success. Using UV-P-exposed males and females, fertility was decreased by 8.75% in the low treatment group and by 15.02% in the high treatment group relative to control. In a reproduction assay with UV-P-exposed males and control females, fertility was decreased by 11.47% in the high treatment group relative to the control. Embryonic exposure to UV-P might have perturbed male sex steroid synthesis as indicated by small changes in blood plasma concentrations of 17β-estradiol and 11-ketotestosterone, and small statistically nonsignificant decreases in mRNA abundances of cyp19a1a, cyp11c1, and hsd17b3. In addition, decreased transcript abundances of genes involved in spermatogenesis, such as nanos2 and dazl, were observed. Decreases in later stages of sperm development were observed, suggesting that embryonic exposure to UV-P impaired spematogenesis, resulting in decreased sperm quantity. The present study is the first to demonstrate latent effects of BUVSs, specifically on fish reproduction. Environ Toxicol Chem 2024;43:385–397. © 2023 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

Short-Term Sediment Dispersal On A Large Retreating Coastal River Delta Via 234th And 7be Sediment Geochronology: The Mississippi River Delta Front, Andrew Courtois, Samuel Bentley, Jillian Maloney, Kehui Xu, Jason Chaytor, Ioannis Y. Georgiou, Michael D. Miner, Jeffrey Obelcz, Navid H. Jafari, Melanie Damour

Faculty Publications

Many Mississippi River Delta studies have shown recent declines in fluvial sediment load from the river and associated land loss. In contrast, recent sedimentary processes on the subaqueous delta are less documented. To help address this knowledge gap, multicores were collected offshore from the three main river outlets at water depths of 25–280 m in June 2017 just after the peak river discharge period, with locations selected based on 2017 U.S. Geological Survey seabed mapping. The coring locations included the undisturbed upper foreset, mudflow lobes, gullies, and the undisturbed prodelta. Nine multicores were analyzed for Beryllium-7 activity, and four cores …

Engineering A Non-Hermitian Second-Order Topological Insulator State In Quasicrystals, Chakradhar Rangi, Ka Ming Tam, Juana Moreno

Faculty Publications

Non-Hermitian topological phases have gained immense attention due to their potential to unlock novel features beyond Hermitian bounds. PT-symmetric (parity time-reversal symmetric) non-Hermitian models have been studied extensively over the past decade. In recent years, the topological properties of general non-Hermitian models, regardless of the balance between gains and losses, have also attracted vast attention. Here, we propose a non-Hermitian second-order topological (SOT) insulator that hosts gapless corner states on a two-dimensional quasicrystalline lattice (QL). We first construct a non-Hermitian extension of the Bernevig-Hughes-Zhang model on a QL generated by the Amman-Beenker tiling. This model has real spectra and supports …

Approaching 25 Years Of Progress Towards Fusarium Head Blight Resistance In Southern Soft Red Winter Wheat (Triticum Aestivum L.), Richard E. Boyles, Carolina Ballén-Taborda, Gina Brown-Guedira, Jose Costa, Christina Cowger, Noah Dewitt, Carl A. Griffey, Stephen A. Harrison, Amir Ibrahim, Jerry Johnson, Jeanette Lyerly, David S. Marshall, R. Esten Mason, Mohamed Mergoum, J. Paul Murphy, Nicholas Santantonio, Gautam Saripalli, Russell Sutton, Vijay Tiwari, David Van Sanford, Zachary J. Winn

Faculty Publications

Tremendous progress has been made in variety development and host plant resistance to mitigate the impact of Fusarium head blight (FHB) since the disease manifested in the southeastern United States in the early 2000s. Much of this improvement was made possible through the establishment of and recurring support from the US Wheat & Barley Scab Initiative (USWBSI). Since its inception in 1997, the USWBSI has enabled land-grant institutions to make advances in reducing the annual threat of devastating FHB epidemics. A coordinated field phenotyping effort for annual germplasm screening has become a staple tool for selection in public and private …

Irrigation Of Sand-Based Creeping Bentgrass Putting Greens With Nanobubble-Oxygenated Water, Eric J. Deboer, Michael D. Richardson, John H. Mccalla

Faculty Publications

Cultural and environmental factors can place creeping bentgrass (Agrostis stolonifera) under extreme stress during the summer months. This stress, coupled with the growth adaptation of creeping bentgrass, can result in shallow, poorly rooted stands of turf. To enhance root zone oxygen and rooting of creeping bentgrass, golf courses use methods such as core and solid-tine aerification, and sand topdressing. An additional method of delivering oxygen to the soil could be irrigation with nanobubble-oxygenated water. The properties of nanobubbles (NBs) allow for high gas dissolution rates in water. Irrigating with NB-oxygenated water sources may promote increased rooting of creeping bentgrass putting …

Hamiltonian Formulation And Symplectic Split-Operator Schemes For Time-Dependent Density-Functional-Theory Equations Of Electron Dynamics In Molecules, François Mauger, Cristel Chandre, Mette B. Gaarde, Kenneth Lopata, Kenneth J. Schafer

Faculty Publications

We revisit Kohn–Sham time-dependent density-functional theory (TDDFT) equations and show that they derive from a canonical Hamiltonian formalism. We use this geometric description of the TDDFT dynamics to define families of symplectic split-operator schemes that accurately and efficiently simulate the time propagation for certain classes of DFT functionals. We illustrate these with numerical simulations of the far-from-equilibrium electronic dynamics of a one-dimensional carbon chain. In these examples, we find that an optimized 4th order scheme provides a good compromise between the numerical complexity of each time step and the accuracy of the scheme. We also discuss how the Hamiltonian structure …

Sedimentary Processes And Instability On The Mississippi River Delta Front Near The Shipwreck Of The Ss Virginia, Nathan Figueredo, Samuel J. Bentley, Jason D. Chaytor, Kehui Xu, Navid Jafari, Ioannis Y. Georgiou, Melanie Damour, Jeffrey Duxbury, Jeffrey Obelcz, Jillian Maloney

Faculty Publications

Sediment cores were collected from a mudflow lobe (80 m water depth) offshore of the Mississippi River’s Southwest Pass in 2017 to better understand the sedimentology near the lobe entraining the SS Virginia shipwreck (sunk by a German U-boat in 1942) and surrounding Mississippi River delta front. Core analyses included ²¹⁰Pb/¹³⁷Cs geochronology, granulometry, and X-radiography. Sediment accumulation rates (SAR) calculated from excess ²¹⁰Pb activity in multicores are 0.22–0.29 cm/y at seabed depths less than 20 cm and 0.29–0.51 cm/y at depths greater than 20 cm. Accumulation rates for ¹³⁷Cs have been ~0.15 to ~0.37 cm/y …

Simultaneous Detection And Quantification Of Multiple Pathogen Targets In Wastewater, Gouthami Rao, Drew Capone, Kevin Zhu, Abigail Knoble, Yarrow Linden, Ryan Clark, Amanda Lai, Juhee Kim, Ching Hua Huang, Aaron Bivins, Joe Brown

Faculty Publications

Wastewater-based epidemiology has emerged as a critical tool for public health surveillance, building on decades of environmental surveillance work for pathogens such as poliovirus. Work to date has been limited to monitoring a single pathogen or small numbers of pathogens in targeted studies; however, few studies consider simultaneous quantitative analysis of a wide variety of pathogens, which could greatly increase the utility of wastewater surveillance. We developed a novel quantitative multi-pathogen surveillance approach (35 pathogen targets including bacteria, viruses, protozoa, and helminths) using TaqMan Array Cards (TAC) and applied the method on concentrated wastewater samples collected at four wastewater treatment …

Energy And Spectrum Efficient Federated Learning Via High-Precision Over-The-Air Computation, Liang Li, Chenpei Huang, Dian Shi, Hao Wang, Xiangwei Zhou, Minglei Shu, Miao Pan

Faculty Publications

Federated learning (FL) enables mobile devices to collaboratively learn a shared prediction model while keeping data locally. However, there are two major research challenges to practically deploy FL over mobile devices: (i) frequent wireless updates of huge size gradients v.s. limited spectrum resources, and (ii) energy-hungry FL communication and local computing during training v.s. battery-constrained mobile devices. To address those challenges, in this paper, we propose a novel multi-bit over-the-air computation (M-AirComp) approach for spectrum-efficient aggregation of local model updates in FL and further present an energy-efficient FL design for mobile devices. Specifically, a high-precision digital modulation scheme is designed …

59th Student Senate Week 2 Meeting Minutes, Zoe Joubert

Student Senate Meeting Minutes

No abstract provided.

Improving Long-Term Flexible Pavement Performance In Louisiana: Effect Of Balanced Asphalt Mixture Design Method And Construction Techniques, Shasank Pant

LSU Master's Theses

Achieving long-term durability and sustainability in flexible pavement is a significant concern in highway infrastructure construction. State highway agencies (SHAs) have implemented various enhanced asphalt mixture design methods and construction practices to address this concern. With advancements in improved asphalt mixture design and construction practices, it is imperative to evaluate the long-term field performance of pavements. Therefore, this study assessed the long-term field performance of flexible pavements in Louisiana, considering enhanced asphalt mixture design methods and construction techniques.

The study consisted of two main sections. In the first section, the field performance of two projects was evaluated: asphalt mixture pavement …

Power Grid Resiliency Enhancement Against Flood-Induced Hazards, Mohadese Movahednia

LSU Doctoral Dissertations

Natural disasters, such as floods, may damage power system assets and lead to widespread and long outages. The impact of flood can be alleviated by preventive actions such as installing tiger dams around power substations before the flood. In this regard, it is imperative that critical substations are identified in terms of the connected load and imposed costs to the system. This study presents a resource allocation approach for protecting power substations against flood events a day ahead of the event. First, the required information for the model is extracted. Flood probability distribution functions are used to generate several flood …

Application Of Learning Processes For Improving Last-Mile Logistics Optimization At Scale, Seyedeh Shaghayegh Rabbanian

LSU Doctoral Dissertations

The escalating demands of omnichannel retailing, rapid urbanization and shifting customer behaviors have propelled last-mile vehicle routing logistics to the forefront of research. This last-mile phase, recognized as a significant contributor to costs and pollution in the supply chain, necessitates efficient route optimization to minimize expenses and environmental impact. This research delves into machine learning based techniques for solving large-scale Vehicle Routing Problem (VRP), a fundamental concern in last-mile logistics, aiming to optimize delivery vehicle routing amidst diverse customer nodes and operational constraints. Three primary research subproblems are analyzed: utilizing machine learning for constructive solutions, Variable Neighborhood Search (VNS) metaheuristic, …

Women At Work: Pathways From Gender Stereotypes To Gender Bias And Discrimination, Madeline E. Heilman, Suzette Caleo, Francesca Manzi

Faculty Publications

Despite important advances, gender-based discrimination continues to hin-der women’s career progress. This review examines the role that gender stereotypes play in promoting gender bias and discrimination. After review- ing what is known about the content of gender stereotypes and examining both their descriptive and prescriptive aspects, we discuss two pathways through which stereotypes result in discrepant work outcomes for women and men. First, we consider how the characterization of women as com- munal but not agentic conflicts with the perceived demands of many male gender-typed jobs and fields, thus promoting perceptions of women’s lack of competence in those areas. Second, …

If You Build It, Will They Come? Assessing Habitat Quality For Marsh Birds At Created Marshes In Southeastern Louisiana, Katherine Aylett Lipford

LSU Master's Theses

Wetland loss occurs at an alarming pace globally, with extremely high rates along the northern Gulf of Mexico. Louisiana loses a football field of wetland every 100 minutes: that is 77,000 m² of wetland bird habitat lost daily. In Louisiana, marsh creation projects combat wetland loss, and while wildlife habitat is often used as a justification for restoration, wildlife receives little to no consideration during and after construction. Habitat characteristics such as site-specific hydrology, vegetation composition, and habitat structure affect the abundance of wetland birds and understanding these features is crucial to creating habitat that will benefit birds. My …

Incubating Education: The Lived Experiences Of Louisiana Elementary And Middle School Teachers When Piloting A 4-H Stem School Enrichment Curriculum, Crystal Rose Ahrens

LSU Doctoral Dissertations

This study addressed a deficiency in the agricultural literacy of the U.S. population by focusing on the challenges that core subject teachers face when integrating agriculture into their curriculum. Using a phenomenological research approach, this investigation explored the lived experiences of Louisiana teachers who piloted a 4-H STEM curriculum, focusing on the growth in agricultural literacy of the teachers while instructing third and eighth-grade students on the agricultural-based and STEM-focused topic of embryology. Employing a transcendental phenomenological approach, I acknowledged my biases through reflexivity and adhered to ethical considerations, including informed consent and confidentiality. Key findings emerged through four themes …

Structural Information On Supramolecular Copper(Ii) Β-Diketonate Complexes From Atomic Force Microscopy And Analytical Ultracentrifugation, Jonathan S. Casey, Ashley R. Walker, Xianglin Zhai, Jayne C. Garno, Paul S. Russo, Andrew W. Maverick

Faculty Publications

Supramolecular Cu(II) complexes were prepared from two trifunctional β-diketone ligands. The ligands (CH3Si(phacH)3 and CH3Si(phprH)3, represented by LH3) contain three aryl-β-diketone moieties joined by an organosilicon group. The complexes have the empirical formula Cu3L2, as expected for combinations of Cu²⁺ and L^3-. Several metal-organic polyhedra (MOPs) [Cu3L2]n are possible (n = 1-10); a dodecahedron (Cu30L20; n = 10; estimated diameter of ca. 5 nm) should be the most stable because its internal bond angles would come closest to ideal values. Atomic force microscopy (AFM), performed on samples deposited from solution onto mica substrates, revealed a distribution of …

Nonlinear Filtering Of Classical And Quantum Spin Systems, Sivaguru S. Sritharan, Saba Mudaliar

Journal of Stochastic Analysis

No abstract provided.

Investigating Environmentally Persistent Free Radicals (Epfrs) Emissions Of 3d Printing Process, Farhana Hasan, Phillip M. Potter, Souhail R. Al-Abed, Joanna Matheson, Slawomir M. Lomnicki

Faculty Publications

In recent years, the emission of particles and gaseous pollutants from 3D printing has attracted much attention due to potential health risks. This study investigated the generation of environmentally persistent free radicals (EPFRs, organic free radicals stabilized on or inside particles) in total particulate matter (TPM) released during the 3D printing process. Commercially available 3D printer filaments, made of acrylonitrile–butadiene–styrene (ABS) in two different colors and metal content, ABS-blue (19.66 µg/g Cu) and ABS-black (3.69 µg/g Fe), were used for printing. We hypothesized that the metal content/composition of the filaments contributes not only to the type and number of EPFRs …

Machine-Learning-Assisted Leak Detection Using Distributed Temperature And Acoustic Sensors, Hayden Gemeinhardt, Jyotsna Sharma

Faculty Publications

Small leaks, many of which often go undetected using conventional gauges, remain an urgent problem for an aging pipeline infrastructure. This article proposes a method that allows for an automated and robust leak detection and localization system by fusing distributed acoustic sensor (DAS) and distributed temperature sensor (DTS) data for machine learning. Distributed fiber-optic sensing creates an advantage over conventional gauges by providing real-time continuous measurements along the entire length of the fiber-instrumented pipeline at a high spatiotemporal resolution and sensitivity that can detect small leaks, as well as the leak location. High sensitivity, however, can create noisy data. Thus, …