Digital Commons Network^™

A Numerical Assessment Of Ocean Alkalinity Enhancement Efficiency On A River-Dominated Continental Shelf—A Case Study In The Northern Gulf Of Mexico, Yanda Ou, Z. George Xue, Xinping Hu

Faculty Publications

A robust high-resolution coupled hydrodynamic-biogeochemical model was applied to the northern Gulf of Mexico to assess the efficiency of river- and ocean-sourced ocean alkalinity enhancement (OAE). Sensitivity tests indicate that the effectiveness of OAE-induced CO2 uptake is primarily influenced by the amount of alkalinity introduced and local wind-driven mixing, with the former determining the overall uptake and the latter affecting short-term variability. Compared to ocean-sourced OAE (direct ocean release), river-sourced OAE (elevated river alkalinity) is more effective and sustainable. River-sourced OAE has higher CO2 uptake efficiency with reduced spatial and temporal uncertainty and greater overall CO2 uptake. For river-sourced OAE, …

Empowering Citizens Through The Development And Deployment Of A Community-Based Environmental Health Reporting Tool, Willow Sauermilch, Jennifer Irving, Margaret Reams, Chuqi Guo, Stephania Cormier, Jennifer Richmond-Bryant

Division of Basic Science Faculty Publications

Community-based participatory research provides communities with an avenue to actively collaborate with environmental researchers. The research aims to gain insight into critical problems of concern to community members while maintaining community autonomy over the research and its outcomes. This article describes the development and implementation of an environmental health communication tool designed to meet the needs of residents of Colfax, Louisiana, a rural community with limited technological access, which is engaging in advocacy with federal and state regulatory agencies to prohibit open burning and open detonation of military and Superfund wastes at a nearby thermal treatment site. We discuss how …

Threat Perceptions, Defensive Behaviors, And The Perceived Suicide Prevention Value Of Specific Firearm Storage Practices, Michael D. Anestis, Craig J. Bryan, Anna Belle O. Bryan, Daniel W. Capron

Faculty Publications

Introduction: Secure firearm storage has been proposed as a suicide prevention method within the military; however, secure storage practices are uncommon. Service members may perceive limited value in secure storage as a suicide prevention tool and threat-related factors may influence such perceptions. Method: A nationally representative sample of firearm-owning military service members (n = 719) was recruited between December 3, 2021 and January 4, 2022 to complete a self-report survey by Ipsos using their KnowledgePanel calibration approach to optimize representativeness. Results: Threat sensitivity was associated with less perceived suicide prevention value across all within-home storage practices as well as out-of-home …

Interactive Effects Of Co2, Temperature, And Nitrate Limitation On The Growth And Physiology Of Strain Ccmp 1334 Of The Marine Cyanobacterium Synechococcus (Cyanophyceae), Alyssa K. Sharbaugh, Edward A. Laws

Faculty Publications

The marine cyanobacterium Synecococcus sp. (CCMP 1334) was grown in a continuous culture system on a 12:12 h light:dark cycle at all combinations of low and high pCO2 (400 and 1000 ppmv, respectively), nutrient availability (nitrate-limited and nutrient-replete conditions), and temperatures of 21, 24, 28, 32, and 35°C. The maximum nutrient-replete growth rate was ~1.15 day⁻¹ at 32–35°C. Median nutrient-replete growth rates were higher at 1000 ppmv than at 400 ppmv pCO2 at all temperatures. Carbon:nitrogen ratios were independent of pCO2 at a fixed relative growth rate (i.e., growth rate ÷ nutrient-replete growth rate) but decreased with increasing temperature. …

Extragalactic Magnetar Giant Flare Grb 231115a: Insights From Fermi /Gbm Observations, Aaron C. Trigg, Rachael Stewart, Alex Van Kooten, Eric Burns, Matthew G. Baring, Dmitry D. Frederiks, Daniela Huppenkothen, Brendan O-Connor, Oliver J. Roberts, Zorawar Wadiasingh, George Younes, Narayana Bhat, Michael S. Briggs, Malte Busmann, Adam Goldstein, Daniel Gruen, Lei Hu, Chryssa Kouveliotou, Michela Negro, Antonella Palmese, Arno Riffeser, Lorenzo Scotton, Dmitry S. Svinkin, Peter Veres, Raphael Zöller

Faculty Publications

Magnetar giant flares (MGFs) are the extremely short, energetic transients originating from highly magnetized neutron stars. When observed in nearby galaxies, these rare events are nearly indistinguishable from cosmological short gamma-ray bursts. We present the analysis of GRB 231115A, a candidate extragalactic MGF observed by Fermi/GBM and localized by INTEGRAL to the starburst galaxy M82. This burst exhibits distinctive temporal and spectral characteristics, including a short duration and a high peak energy, consistent with known MGFs. Time-resolved analysis reveals rapid spectral evolution and a clear correlation between luminosity and spectral hardness, providing robust evidence of relativistic outflows. Archival Chandra data …

Earliest Ancient Maya Salt Production In Southern Belize: Excavations At Jay-Yi Nah, Heather Mckillop, E. Cory Sills

Faculty Publications

Salt works along the Yucatan coasts of Mexico and Belize provide a record of salt production for inland trade during the height of Late Classic Maya civilisation (AD 550-800). At the Paynes Creek Salt Works in Belize, production focused on the creation of salt cakes by boiling brine in pots supported over fires in dedicated salt kitchens. Underwater excavations at the Early Classic (AD 250-550) site of Jay-yi Nah now indicate there was a longer and evolving tradition of salt making in the area, one that initially employed large, incurved bowls to meet local or down-the-line trade needs before inland …

Using Teacher Prompts To Increase Leadership Skills In Preschool Children, Cynthia F. Dicarlo, Margaret Mary Sulentic Dowell, Michelle Fazio-Brunson, Sarah W. Gauthreaux

Faculty Publications

Background: Early childhood leadership leads to positive outcomes for young children, including social competence. Objective: The purpose of the present study was to examine the leadership behavior exhibited by three preschool aged children and to determine if teacher prompting could increase the frequency of leadership behaviors exhibited by preschool children. Methods: A single case research design was utilized; specifically, we employed a multiple baseline design across preschool children to measure child leadership behaviors and teacher prompting. Results: Baseline observations revealed that children engaged in Parten’s original 1933 framework of both directing and following, reciprocally directing or sharing leadership, and directing …

Assessing Water Quantity And Quality In The Mississippi River Valley Alluvial Aquifer And Coastal Louisiana Through Integrated Airborne Electromagnetic And Borehole Data, Michael George Henin Attia Khalil

LSU Doctoral Dissertations

Numerical modeling has contributed significantly to the understanding of groundwater systems. Many challenges are associated with constructing groundwater models which include an accurate understanding of the geology and aquifer parameters estimation. Traditionally boreholes are a successful way to capture geological features, however, boreholes often have sparse data. Airborne electromagnetic (AEM) data allows for efficient and cost-effective surveying of large areas, providing valuable information about the subsurface electrical resistivity. By bridging the gap between boreholes, AEM data offers a broader view of the aquifer system's structure and heterogeneity. However, interpreting geophysical AEM data has uncertainties. Developing a framework to apply the …

Supplemental Data For "Strong-Field Ionization With Few-Cycle, Mid-Infrared Laser Pulses Induces A Localized Ionization Followed By Long-Lasting Charge Migration In Halogenated Organic Molecules", Kyle A. Hamer, Mette B. Gaarde, François Mauger

Physics & Astronomy Datasets

Supplemental data for Hamer et al. (2024), which includes the time-dependent density-functional theory simulation data and Python scripts used to produce the figures in the paper.

This work was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Award No. DE-SC0012462. Portions of this research were conducted with high performance computational resources provided by Louisiana State University (http://www.hpc.lsu.edu) and the Louisiana Optical Network Infrastructure (http://www/loni.org).

The Full Range Leadership Model (Frlm): Department Head Perceptions Of Leadership Style And Development, Stephanie Elaine Heroman

LSU Doctoral Dissertations

The purpose of this study is to discover the perceived leadership styles of department heads as categorized by the Full Range Leadership Model (FRLM), developed by Avolio and Bass (1991). The FRLM categorizes leadership style along a continuum, from laissez-faire leadership, to transactional leadership, and ultimately transformational leadership. Even though department heads occupy a pivotal leadership role, many do not have formal leadership training, and instead rise to power through disciplinary expertise. This study will collect data on the experiences contributing to the development of leadership style in department heads. Understanding the leadership styles and experiences of department heads will …

Thermal Noise Measurement Below The Standard Quantum Limit, Ronald Pagano

LSU Doctoral Dissertations

Quantum mechanics places sensitivity restrictions on physical measurements. These limitations manifest themselves in interferometric force and displacement measurements as uncertainty both in the photon number measured at a photodetector (shot noise), and in the quantum radiation pressure applied to the interferometer (quantum back action noise manifested as quantum radiation pressure noise). The balance between shot noise and quantum radiation pressure noise imposes the Standard Quantum Limit (SQL). A large body of work has been dedicated to measuring these quantum effects and mitigating them. Owing to the inherently small scale at which quantum effects are visible, classical effects must be subverted …

Studying The Low-Lying Structure Of 9b Via The 10b(3he,A)9b Reaction, Rachel M. Shaffer

LSU Doctoral Dissertations

The unstable nature of ⁹B makes it a challenging isotope to study. The first-excited state of ⁹B has been particularly difficult to characterize. Since the first experimental observation of this state in 1955, many experimental and theoretical nuclear structure studies have sought to classify it, but with large discrepancies in the energy and width values from these results, the properties of the state remain inconclusive.

An experiment using the ¹⁰B(³He,α)⁹B reaction was performed at the John D. Fox Superconducting Linear Accelerator Laboratory at Florida State University in an effort to populate and characterize …

Synthesis And Characterization Of Bimetallic Plasmonic Nanoparticles Using Linear And Nonlinear Spectroscopy, Daniel Babayode

LSU Doctoral Dissertations

Recent exploration in the field of nanomaterials has led to the investigation of noble metal nanoparticles for various nanomedical applications. The spectroscopy of these nanoparticles is studied using both linear and nonlinear optical processes such as second harmonic generation (SHG), two-photon fluorescence (TPF), and extinction spectroscopy. Details pertaining to the growth dynamics of silver-gold core-shell (Ag@Au CS) nanoparticles (NPs) and gold-silver-gold core-shell-shell (Au@Ag@Au CSS) nanoparticles (NPs) are currently being investigated in order to obtain better control and optimization of the nanoparticle size and surface morphology. Transmission electron microscopy (TEM) images show that the nanoparticles have tunable core and shell sizes …

Johann Georg Hamann And The Liberal Project, Jesse D. Ansley

LSU Doctoral Dissertations

This dissertation examines the political thought of Johann Georg Hamann, his relationship to liberalism, and the importance to modern concerns for consensus formation and intercultural dialogue. This contributes to the line of literature sparked by Isaiah Berlin debating the political legacy of Hamann and its relation to the development of modern politics. Berlin labels Hamann an anti-rationalist whose current developed into the ideology of the Nazi party. My work supports the countervailing arguments that Hamann’s work is importantly different from the Romantics he inspired and even more so from the Nazis. By examining two complete works and a number of …

The Impact Of Outdoor Youth Education: An Examination Of The Social, Personal, And Environmental Developmental Outcomes Experienced By Youth At A Residential 4-H Summer Camp, Adam M. O'Malley

LSU Doctoral Dissertations

One of the most innovative ways that 4-H has fostered agricultural innovation and hands-on, experiential education has been through the development of youth outdoor education programs, more commonly known as 4-H Camp. State 4-H Camps and national camping events, including the inaugural National 4-H Conference, emerged following the establishment of localized county club camps. Three years after establishing the first 4-H Camp, more than 1,700 had emerged across the U.S., with early attendance exceeding 100,000 youth participants.

As a direct result of these early successes, the 4-H Camping movement has become celebrated as a novel technique to motivate youth to …

The Importance Of Fauna-Mediated Sediment O2 Consumption In The Ngom Hypoxic Zone, Hannah Beck, Kanchan Maiti

Faculty Publications

The northern Gulf of Mexico (NGOM) coastal shelf adjacent to the Mississippi and Atchafalaya rivers system experiences strong seasonal hypoxia in the late summer and coupled physical-biological models suggest that hypoxia formation in the NGOM is sensitive to benthic biogeochemical processes. However, the processes driving sediment oxygen consumption and their relationship to bottom oxygen concentration remain enigmatic. This study for the first time concurrently measured in situ total oxygen uptake (TOU) and diffusive oxygen uptake (DOU) during two different hypoxia seasons. The relatively large DOU: TOU ratio of 0.33 ± 0.07 observed during this study suggests more significant benthic infauna …

Flood Risk And Mitigation Calculator Tool To Support Decision-Making For Enhancing Community Resilience: A Case Study Of The U.S.A. Gulf Coastal Region, Rubayet Bin Mostafiz, Ayat Al Assi, Arash Taghinezhad, Carol J. Friedland, Robert V. Rohli, Md Adilur Rahim, Christopher T. Emrich, Melanie Gall, Eric Johnson

Faculty Publications

Real-estate websites make it easy to find and access information about a home. Information on property value, square footage, number of rooms, quality of schools, crime rates, and more is readily available. Some of these platforms have begun integrating climate-related risks in generic ways. However, this information provides limited if any actionable value and is unlikely to guide people’s decision-making on buying or renting a home, deciding where to vacation, or investing in a property. Making residents aware of the natural hazard risks to which their homes may be exposed is an important component of making communities more resilient. Both …

Trajectory Of Coastal Wetland Soil Physical And Microbial Properties 6+ Years After Thin Layer Placement Sediment Amendment, Jacob Z. Cheng, Jacob F. Berkowitz, John R. White

Faculty Publications

The intentional thin layer placement (TLP) of dredged sediment is an increasingly popular approach to maintaining marsh elevation and restoring degraded marshes, which can improve conditions for vegetation establishment. Prior TLP restoration projects, assessed shortly after construction, evaluated soil, hydrology, plant, and faunal responses. However, few long-term studies (>3 yrs) investigate TLP-induced shifts in soil properties and especially properties related to biogeochemical cycling. In response, this study revisited a salt marsh 6+ years after TLP restoration and determined both soil physiochemical and microbial properties related to plant growth (nitrogen (N) mineralization) and water quality improvement (denitrification). Data were compared …

The Impact Of Seasonal Hydrological Disturbances On The Presence And Formation Of Toxic Cyanobacteria Blooms In Coastal Louisiana, Courtney Nicole Hammond, Sibel Bargu, Caitlin R.R. Turner, Matthew Hiatt, John R. White

Faculty Publications

Estuaries in the Gulf, especially Lake Pontchartrain Estuary in southeastern Louisiana, USA, are experiencing significant changes due to climate change and coastal restoration efforts. Lake Pontchartrain Estuary receives nutrient-rich Mississippi River water through a controlled diversion called Bonnet Carré Spillway (BCS), which has been associated with toxic cyanobacterial blooms (cyanoHABs). This study examines the seasonal factors influencing cyanoHABs in the Lake Pontchartrain Estuary when the BCS is closed, addressing gaps in the understanding of HABs related to other physical drivers. Field samples collected in 2021, during the closure of the spillway, revealed significant evidence of seasonal variations in cyanoHAB formation. …

Corrigendum: Diatom Transcriptional And Physiological Responses To Changes In Iron Bioavailability Across Ocean Provinces (Frontiers In Marine Science, (2017), 4, (360), 10.3389/Fmars.2017.00360), Natalie R. Cohen, Kelsey A. Ellis, Robert H. Lampe, Heather Mcnair, Benjamin S. Twining, Maria T. Maldonado, Mark A. Brzezinski, Fedor I. Kuzminov, Kimberlee Thamatrakoln, Claire P. Till, Kenneth W. Bruland, William G. Sunda, Sibel Bargu, Adrian Marchetti

Faculty Publications

In the published article, there was an error in Figure 3 as published. The initial (T0) phytoplankton community composition at site C2 was incorrectly displayed, with prasinophytes erroneously appearing as relatively abundant taxa. The corrected Figure 3 appears below. The average transcript proportions of phytoplankton taxa (outer charts) and diatom genera (inner charts) from initial seawater (T0) and during the first time point (T1; see Supplementary Table 1) within the Fe addition (Fe) and DFB addition (DFB) treatments at each site. Note that for site O5, the T2 control (Ctl) treatment is provided as the Fe-limited comparison. A text correction …

History, Annotated Gazetteer, And Bibliography Of Ornithology In Kalimantan, Indonesian Borneo, Frederick H. Sheldon, Mohammad Irham, Daisy G. S. Kho, Erik Meijaard, Subir B. Shakya, Dewi M. Prawiradilaga, Sebastianus (Bas) Van Balen

Occasional Papers of the Museum of Natural Science, Louisiana State University

Kalimantan comprises nearly three quarters of the island of Borneo and is the place where scientific study of Bornean birds began. We describe the history of bird research in Kalimantan from its beginning, highlighting the ornithologists who explored the region and how their interests and methods changed over time, from a concentration on specimen collection, to examinations of community ecology, to conservation in the face of habitat change and species depletion, to the latest investigations using satellite, genetic, and digital technology. We also highlight some future directions for research, especially the need for more work on basic ecology and biogeography. …

Mini Worldlit: A Dataset Of Contemporary Fiction From 13 Countries, Nine Languages, And Five Continents, Andrew Piper, Mathias Iroro Orhero, David Bamman, Emrah Peksoy, Christina Han, Pallavi Rastogi, Jens Bjerring-Hansen, Sebastian Rasmussen, Hoyt Long, Roel Smeets, Itay Marienberg-Milikowsky, Alexandra Stuart, Tom Mcenaney, Mads Rosendahl Thomsen

Faculty Publications

World literature plays a key role in understanding the global diversity of human storytelling. However, datasets suitable for large-scale cross-cultural analysis remain limited. Responding to the increasing digitization of literary texts and the need for more diverse and multilingual resources, we introduce Mini Worldlit, a manually curated dataset of 1,192 works of contemporary fiction from 13 countries, representing nine languages across five continents. Mini Worldlit employs consistent cross-cultural selection criteria, overseen by scholarly experts, to ensure geographic, linguistic, and stylistic coherence. The dataset provides a foundation for future comparative studies of global literary cultures, offering a template for cross-cultural sampling. …

A Big Data Approach To Modelling Urban Population Density Functions: From Monocentricity To Polycentricity, Cehong Luo, Yujie Hu, Fahui Wang

Faculty Publications

Urban studies have a long tradition of examining the regularity of urban structure by modelling urban population density functions and probing the theoretical or behavioural foundation behind it. Previous studies commonly used census data in areal units such as census tracts or census block groups, which varied a great deal in area size and shape and led to the zonal and scale effects, commonly referred to as the modifiable areal unit problem (MAUP). This study uses big data of individual vehicle trips in Tampa, Florida, to define the precise population and employment distribution locations, and then aggregates them with uniform …

Can Americans’ Trust In Local News Be Trusted? The Emergence, Sources, And Implications Of The Local News Trust Advantage, Erik Peterson, Joshua P. Darr, Maxwell B. Allamong, Michael Henderson

Faculty Publications

Despite eroding consensus about credible political news sources, much of the public still trusts local media. We assess the emergence, sources, and implications of the trust advantage local news holds over national media. We argue the public now uses a news outlet's local orientation as a shortcut to assess its credibility. In survey experiments, we find unfamiliar news outlets are trusted more when they have a local cue in their name. In surveys where people evaluate digital sources covering their community, this heuristic leads the public to trust unreliable information providers that signal a local focus more than high-quality sources …

Primary Processes Of Depolymerization Of Lignin Dispersed Into Gas Phase, Marwan Y. Rezk, Mohamad Barekati-Goudarzi, Divine Nde, Dorin Boldor, Slawomir Lomnicki, Stephania Cormier, Lavrent Khachatryan

Division of Basic Science Faculty Publications

The primary depolymerization processes of hydrolytic lignin (HL) are examined, focusing on the formation of intermediate oligomers and bulky environmentally persistent free radicals (EPFRs). Fragmentation of HL was conducted in a continuous atomization (CA) fast flow reactor, where HL, dissolved in a 9:1 acetone-to-water solution, was dispersed. Results indicated that HL fragmentation occurs significantly faster in the gas phase in comparison to the literature rate of formation of major biofuel-phenolic compounds. In other words, the formation of phenolic compounds occurs at much lower rate constants being the limiting stage for lignin depolymerization. The critical role of surface associated reactions for …

Beyond Reoffending And Rearrest: Expanding The Collateral Consequences Of Formal Processing To Youth Homelessness, Natasha Chlebuch, Jennifer Paruk, Caitlin Cavanagh, Paul J. Frick, Laurence Steinberg, Elizabeth Cauffman

Faculty Publications

There is robust evidence that juvenile justice contact during formative years is associated with deleterious outcomes. The effect of juvenile court intervention on youth homelessness, however, has received scant empirical attention despite evidence that many justice-involved youth are represented in the unhoused youth and adult population. This study leverages data collected from the Crossroads Study (N = 1115), a longitudinal, multi-site study to explore the impact of formal processing on subsequent experiences with homelessness. This study found that even when accounting for the effect of detention and other factors associated with youth homelessness, youth who were formally processed were twice …

Alternative Theories Of Covid-19: Social Dimensions And Information Sources, Wesley Shrum, Paige Miller, Nana Osei Asiamah, Fangyue Zou

Faculty Publications

While scientific understanding of the COVID-19 pandemic increased, conspiracy theories undermined the foundations of public health policy, making it significantly more difficult both to discuss and to implement. Popular alternative narratives include the claim that government was using restrictions to control people's behavior, and that the pandemic was caused by 5G cellular technology. We examine the extent to which alternative beliefs were associated with sociodemographic characteristics and the sources through which people acquired information during the pandemic. Our analysis uses a demographically balanced online survey of 10,022 participants from 50 US states, collected during August of 2021. Results indicate that …

Complex Models Of Sequence Evolution Improve Fit, But Not Gene Tree Discordance, For Tetrapod Mitogenomes, Benjamin S. Toups, Robert C. Thomson, Jeremy M. Brown

Faculty Publications

Variation in gene tree estimates is widely observed in empirical phylogenomic data and is often assumed to be the result of biological processes. However, a recent study using tetrapod mitochondrial genomes to control for biological sources of variation due to their haploid, uniparentally inherited, and non-recombining nature found that levels of discordance among mitochondrial gene trees were comparable to those found in studies that assume only biological sources of variation. Additionally, they found that several of the models of sequence evolution chosen to infer gene trees were doing an inadequate job of fitting the sequence data. These results indicated that …

Academic Screening In Middle School: Exploring Bivariate And Intraindividual Relations In Reading And Math Performance, Kelly N. Clark, Garret J. Hall

Faculty Publications

Early adolescence is a pivotal time for academic development; however, the vast majority of research on reading and math development within a multitiered system of support has been conducted among elementary students. Using triannual (Fall, Winter, Spring) academic screening data, we examined the transactional development of reading and math skills among sixth and seventh grade students (N = 1,693) using Bayesian longitudinal structural equation modeling (SEM). We find equivocal support for four of the five types of longitudinal SEMs tested (dual-change, linear change, proportional change, latent curve with structured residuals, and random-intercepts cross-lagged models). Stable between-person differences in math and …

Book Challenges And Censorship Attempts In Louisiana: A Case Study, Jennifer E. Steele

Faculty Publications

Book challenges and censorship have long played a significant role in the cultural and educational landscapes of the United States. In recent years, Louisiana has become a focal point in national conversations about intellectual freedom, public and school library governance, parental rights, and the political pressures surrounding children and young adult literature. This dynamic environment has led to significant debates about what materials should be accessible to young people, how libraries should be managed, and what role the state and local governments should play in determining the availability of information. The rise in book challenges across Louisiana reflects national trends …