Digital Commons Network^™

Interactive Effects Of Co2, Temperature, And Nutrient Limitation On The Growth And Physiology Of The Marine Coccolithophore Emiliania Huxleyi (Prymnesiophyceae), James P. Bradley, Edward A. Laws

Faculty Publications

The marine coccolithophore Emiliania huxleyi (strain PnB 272 B10) was grown in a continuous culture system on a 12:12 light:dark cycle at temperatures from 10 °C to 28 °C under either nutrient-replete or nitrate-limited conditions and at either 493 ppmv (low) or 1003 ppmv (high) partial pressures of CO2 (pCO2). The maximum and minimum nutrient-replete growth rates were 0.751 d⁻¹ at 20 °C and 0.365 d⁻¹ at 10 °C, respectively. Ratios of particulate organic carbon (POC) to particulate inorganic carbon (PIC) were independent of pCO2 and of the degree of nitrate limitation but were temperature dependent and lower …

The Effects Of Anthropogenic Stressors On Above- And Belowground Phytochemical Diversity Of The Wetland Grass, Phragmites Australis, Andrea E. Glassmire, Ana L. Salgado, Rodrigo Diaz, Joseph Johnston, Laura A. Meyerson, Joshua S. Snook, James T. Cronin

Faculty Publications

Coastal wetlands face threats from climate change-induced flooding and biological invasions. Plants respond to these stressors through changes in their phytochemical metabolome, but it is unclear whether stressors affecting one tissue compartment (e.g., leaves) create vulnerabilities in others (e.g., roots) or elicit similar responses across tissues. Additionally, responses to multiple simultaneous stressors remain poorly understood due to the focus on individual metabolites in past studies. This study aims to elucidate how the phytochemical metabolome of three Phragmites australis (Cav.) lineages, common in the Mississippi River Delta, responds to flooding and infestation by the non-native scale insect Nipponaclerda biwakoensis (Kuwana). Among …

Historic Breeding Practices Contribute To Germplasm Divergence In Leaf Specialized Metabolism And Ecophysiology In Cultivated Sunflower (Helianthus Annuus), Jordan A. Dowell, Alan W. Bowsher, Amna Jamshad, Rahul Shah, John M. Burke, Lisa A. Donovan, Chase M. Mason

Faculty Publications

Premise: The use of hybrid breeding systems to increase crop yields has been the cornerstone of modern agriculture and is exemplified in the breeding and improvement of cultivated sunflower (Helianthus annuus). However, it is poorly understood what effect supporting separate breeding pools in such systems, combined with continued selection for yield, may have on leaf ecophysiology and specialized metabolite variation. Methods: We analyzed 288 lines of cultivated H. annuus to examine the genomic basis of several specialized metabolites and agronomically important traits across major heterotic groups. Results: Heterotic group identity supports phenotypic divergences between fertility restoring and cytoplasmic male-sterility maintainer …

Combined Toxicity Of Multi-Walled Carbon Nanotubes And Cu2+ On The Growth Of Ryegrass: Effect Of Surface Modification, Dose, And Exposure Time Pattern, Wenwen Xie, Cheng Peng, Weiping Wang, Xiaoyi Chen, Jiaqi Tan, Wei Zhang

Faculty Publications

The escalating release of multi-walled carbon nanotubes (MWCNTs) into the environment has raised concerns due to their potential ecotoxicological impacts. However, their combined phytotoxicity with heavy metals such as copper (Cu) is still unclear. This study investigated the individual and combined toxic effects of MWCNTs (MWCNT, MWCNT-OH, and MWCNT-COOH) and Cu²⁺ on ryegrass (Lolium multiflorum), uniquely considering different addition orders. The results show that Cu severely inhibited the growth of ryegrass while MWCNTs exhibited a hormesis effect on ryegrass. When MWCNT and Cu were combined, the malondialdehyde (MDA) content in ryegrass showed a 32.39% increase at 20 mg/L MWCNT …

The Roles Of Vicarious Trauma Exposure And Perceived Social Support In Codeine Syrup Misuse Among Black Men Living In Prisons, Jardin Dogan-Dixon, Shawndaya S. Thrasher, Shemeka Thorpe, Paris Wheeler, Danelle Stevens-Watkins

Faculty Publications

Using General Strain Theory, this study investigates the effects of vicarious trauma exposure and perceived social support on nonmedical codeine syrup misuse among Black incarcerated men nearing community re-entry. Data were drawn from the Helping Incarcerated Men project, a study examining mental health, substance misuse, and human immunodeficiency virus (HIV) risk behaviors among Black men living in prisons who were within 180 days of release. A total of 200 Black men self-reported demographics (i.e., age and length of incarceration after age 18), vicarious trauma exposure (e.g., ever witnessing an assault with a weapon and a sudden accidental death), perceived social …

Cultural Predictors Of Self-Esteem Among Black Women With Criminal Justice Involvement And Herpes Simplex Virus, Natalie Malone, Jardin N. Dogan-Dixon, Shemeka Thorpe, Shawndaya S. Thrasher, Paris Wheeler, Danelle Stevens-Watkins, Carrie B. Oser

Faculty Publications

Black women have disproportionately alarming HSV-2 infection rates yet receive little attention in sexual health literature. Using a strengths-based resilience framework, this study sought to determine culturally relevant protective predictors of self-esteem for Black women who are justice-involved and have HSV-2. The authors conducted secondary data analysis on data from the “Black Women in the Study of Epidemics (B-WISE) Project,” a longitudinal prospective study investigating health disparities and health services utilization among Black women with justice involvement. At baseline, N = 151 Black women with HSV-2 who were incarcerated or on probation completed survey measures assessing self-esteem, ethnic identity affirmation …

Precision Synthesis Of Conjugated Polymer Films By Surface-Confined Stepwise Sonogashira Cross-Coupling, Sang Gil Youm, Mitchell T. Howell, Chien Hung Chiang, Lu Lu, Neepa M.K. Kuruppu Arachchige, John F. Ankner, Joseph Strzalka, Yaroslav Losovyj, Jayne C. Garno, Evgueni E. Nesterov

Faculty Publications

Thin films of poly(arylene ethynylene)-conjugated polymers, including low-energy-gap donor–acceptor polymers, can be prepared via stepwise polymerization utilizing surface-confined Sonogashira cross-coupling. This robust and efficient polymerization protocol yields conjugated polymers with a precise molecular structure and with nanometer-level control of the organization and the uniform alignment of the macromolecular chains in the densely packed film. In addition to high stability and predictable and well-defined molecular organization and morphology, the surface-confined conjugated polymer chains experience significant interchain electronic interactions, resulting in dominating intermolecular π-electron delocalization which is primarily responsible for the electronic and spectroscopic properties of polymer films. The fluorescent films demonstrate …

Venomcap: An Exon-Capture Probe Set For The Targeted Sequencing Of Snake Venom Genes, Scott L. Travers, Carl R. Hutter, Christopher C. Austin, Stephen C. Donnellan, Matthew D. Buehler, Christopher E. Ellison, Sara Ruane

Faculty Publications

Snake venoms are complex mixtures of toxic proteins that hold significant medical, pharmacological and evolutionary interest. To better understand the genetic diversity underlying snake venoms, we developed VenomCap, a novel exon-capture probe set targeting toxin-coding genes from a wide range of elapid snakes, with a particular focus on the ecologically diverse and medically important subfamily Hydrophiinae. We tested the capture success of VenomCap across 24 species, representing all major elapid lineages. We included snake phylogenomic probes in the VenomCap capture set, allowing us to compare capture performance between venom and phylogenomic loci and to infer elapid phylogenetic relationships. We demonstrated …

Characterization Of Health And Safety Resources For Athletes With Sickle Cell Trait At Ncaa Institutions, Susan W. Yeargin, Courtney M. Meyer, Rebecca M. Hirschhorn, Abbi D. Lane, Shawn M. Arent, Clint R. Haggard

Faculty Publications

Yeargin, SW, Meyer, CM, Hirschhorn, RM, Lane, AD, Arent, SM, and Haggard, CR. Characterization of health and safety resources for athletes with sickle cell trait at NCAA institutions. J Strength Cond Res 38(11): 1967-1973, 2024 - The purpose of this study was to report the prevalence of student-athletes with sickle cell trait (SCT), determine which screening practices are most commonly used, describe the health and human performance services provided to athletes, and ascertain if differences between National Collegiate Athletic Association (NCAA) designations or divisions exist. A cross-sectional survey design was used to query healthcare administrators regarding SCT resources at their …

The Sec Spanish Consortium: Foundations For Linguistic Gratuity And Language Documentation Among Latinx Populations In New Destination Communities Of The U.S. South, Stephen Fafulas, Chad Howe, Rafael Orozco, Alicia Cipria, Erin O’Rourke, Nina Moreno, Matthew J. Van Hoose

Faculty Publications

Latinx populations in the USA have grown steadily in recent decades, with significant increases taking place in “new destination communities” of the U.S. South. The focus of our paper is to highlight opportunities for working with these populations, including traditional sociolinguistic ethnographies and community-engaged research. We highlight an initiative named “The SEC Spanish Consortium” which is an interinstitutional collaboration centered on scholarship and service involving Latinx populations in new destination communities of the U.S. South. We show that ongoing and future scholarly work in the U.S. South can act as a mechanism for documenting these emerging Latinx communities while simultaneously …

Editorial Introduction: Policy Actors, Dynamics, And Developments—New Insights From Process Theories And Methodological Applications, Geoboo Song, Gwen Arnold, Melissa K. Merry, Davor Mondom, Ben Galloway, Briana Huett, Camille Gilmore, Saba Siddiki, Holly L. Peterson, Creed Tumlison, Heasun Choi, Meerim Seiitova

Faculty Publications

No abstract provided.

Prediction Of Individual Weight Loss Using Supervised Learning: Findings From The CalerieTm 2 Study, Christina Glasbrenner, Christoph Höchsmann, Carl F. Pieper, Paulina Wasserfurth, James L. Dorling, Corby K. Martin, Leanne M. Redman, Karsten Koehler

Clinical Research Faculty Publications

Background: Predicting individual weight loss (WL) responses to lifestyle interventions is challenging but might help practitioners and clinicians select the most promising approach for each individual. Objective: The primary aim of this study was to develop machine learning (ML) models to predict individual WL responses using only variables known before starting the intervention. In addition, we used ML to identify pre-intervention variables influencing the individual WL response. Methods: We used 12-mo data from the comprehensive assessment of long-term effects of reducing intake of energy (CALERIETM) phase 2 study, which aimed to analyze the long-term effects of caloric restriction on human …

Deephive: A Reinforcement Learning Approach For Automated Discovery Of Swarm-Based Optimization Policies, Eloghosa Ikponmwoba, Opeoluwa Owoyele

Faculty Publications

We present an approach for designing swarm-based optimizers for the global optimization of expensive black-box functions. In the proposed approach, the problem of finding efficient optimizers is framed as a reinforcement learning problem, where the goal is to find optimization policies that require a few function evaluations to converge to the global optimum. The state of each particle within the swarm is defined as its current position and function value within a design space, and the particles learn to take favorable actions that maximize the reward, which is based on the final value of the objective function. The proposed approach …

Research Gaps And Priorities For Quantitative Microbial Risk Assessment (Qmra), Kerry A. Hamilton, Joanna Ciol Harrison, Jade Mitchell, Mark Weir, Marc Verhougstraete, Charles N. Haas, A. Pouyan Nejadhashemi, Julie Libarkin, Tiong Gim Aw, Kyle Bibby, Aaron Bivins, Joe Brown, Kara Dean, Gwyneth Dunbar, Joseph N.S. Eisenberg, Monica Emelko, Daniel Gerrity, Patrick L. Gurian, Emma Hartnett, Michael Jahne, Rachael M. Jones, Timothy R. Julian, Hongwan Li, Yanbin Li, Jacqueline Mac Donald Gibson, Gertjan Medema, J. Scott Meschke, Alexis Mraz, Heather Murphy, David Oryang, Emmanuel De Graft Johnson Owusu-Ansah, Emily Pasek, Abani K. Pradhan

Faculty Publications

The coronavirus disease 2019 pandemic highlighted the need for more rapid and routine application of modeling approaches such as quantitative microbial risk assessment (QMRA) for protecting public health. QMRA is a transdisciplinary science dedicated to understanding, predicting, and mitigating infectious disease risks. To better equip QMRA researchers to inform policy and public health management, an Advances in Research for QMRA workshop was held to synthesize a path forward for QMRA research. We summarize insights from 41 QMRA researchers and experts to clarify the role of QMRA in risk analysis by (1) identifying key research needs, (2) highlighting emerging applications of …

Redefining The Art Songs Of Maude Valérie White, Sarah C. Rees

LSU Doctoral Dissertations

Maude Valérie White (1866-1937) was an English composer during the Victorian Era. Her main output was in the genre of art song, of which she wrote more than two hundred during her life. Her music was very popular at the height of her career around 1880-1890, but fell out of favor with the general public in line with the general reaction against Victorian art and ideals. This written document focuses on the life of Maude Valérie White contextualized within the ideals of Victorian womanhood. It will explore the development of her musical style through eight song analyses: The Devout Lover, …

A Qualitative Examination Of Grief, Mourning, And Bereavement Among Grief-Based Mental Health Providers, Nia Nicks

LSU Doctoral Dissertations

This study explored grief, growth, religion, spirituality, and therapeutic rituals from the

perspectives of clinicians and therapists. Specifically, this study explored ways that therapeutic rituals can promote growth and healing. The research explored ways that therapeutic rituals may impede growth and healing, how religion and spirituality can promote growth and healing, as well as how religion and spirituality may impede growth and healing. The research also

explored ways that clinicians and therapists incorporate religion and spirituality into therapy to promote growth and healing. The research data was collected from therapists and clinicians who specialize in treating grief and loss ( …

Do #Blm At The Plantation: A Study Of Plantation Tourism After The Racial Reckoning Of 2020, Denetria N. Lee

LSU Master's Theses

Following the murder of George Floyd at the hands of Minneapolis police officer Derek Chauvin, the widespread public protest of racial injustice created a groundswell that prompted corporate and media responses, so much so that by the end of the summer of 2020, it seemed as if "Black Lives Mattered" everywhere and to everyone. Public response incentivized subsequent corporate response in financial pledges and other commitments to racial justice initiatives until 2020, which became known as the year that America confronted racism or the racial reckoning of 2020. While the public demanded acknowledgment of the many forms of contemporary racial …

The Structure, Oxidation States, And Energetics Of Co Nanoparticles On Ceo2(111): An Stm And Dft Study, Md Saeedur Rahman, Nishan Paudyal, Linze Du Hill, Jing Zhou, Ye Xu

Faculty Publications

Co nanoparticles (NPs) dispersed on ceria have been widely studied as active catalytic materials for many industrially relevant reactions. The detailed nature of such particles and the factors affecting their interaction with ceria remain to be better understood. In this study, a very low coverage (∼0.02 ML) of Co is deposited on a model CeO2(111) thin-film surface and is examined using scanning tunneling microscopy (STM) and X-ray photoelectron spectroscopy (XPS). The Co NPs that nucleate on terrace sites grow with coverage in this range to a maximum size of ca. 40 Co atoms, with an average diameter and height of …

Performance Analysis Of C++ Parallel Algorithms In Hpx, Srinivas Yadav Singanaboina

LSU Master's Theses

The exponential growth in computational power and the increasing demand for high-performance applications have driven the need for greater parallel efficiency. Over the years, the number of cores in consumer-level CPUs and high-performance computing (HPC) systems has grown significantly. In response, numerous parallel programming li- braries have been developed. Each of these libraries offers unique mechanisms to enhance parallel performance. In this paper, we investigate the performance of five such paral- lel programming backends: C++ std::execution::par, OpenMP, TBB, Taskflow, and HPX. We evaluate these libraries using two sets of benchmarks. The first set focuses on standard C++ STL algorithms, including …

Exploring Pre-Service Teachers' Experiences With Emerging Technologies In Secondary Education: A Phenomenological Study, Richelle M. Decuir

LSU Doctoral Dissertations

This research was an investigation of the role of emerging technologies in preparing pre-service teachers to engage with secondary learners effectively. A phenomenological approach was utilized to explore how instructional design models and constructivist learning theories shape technology training in two Southeastern public universities. The research was focused on pre-service teachers' experiences developing digital competencies, integrating instructional design, and utilizing emerging technologies in educational settings. Data was collected through semi-structured interviews and demographic surveys to understand the participants’ perspectives comprehensively. The study findings revealed that while pre-service teachers recognize the value of technology in enhancing student engagement and supporting personalized …

Enhancing Writing By Increasing Metacognitive Skills Through Socratic Seminars In A High Poverty Middle School Social Studies Classroom: An Intrinsic Case Study, Kirsten Hickingbottom

LSU Doctoral Dissertations

The purpose of this intrinsic case study was to better understand the role metacognitive skills play within classroom settings to increase students’ writing through Socratic Seminars. A predominant question guided this study: Can improving student metacognition through the repetitive use of questioning techniques in Socratic Seminars lead to improved writing skills? This question, along with four additional research questions guided the research. There is a need for more activities that promote metacognition due to its correlation with academic achievement, critical thinking skills, problem-solving abilities, and perceived self-efficacy (Keus, 2020). The significance of this study was to examine a method of …

An In-Situ Method For Quantifying Entropy Generation In Fatigue Via A Novel Thermographic Approach, Peyton J. Wilson

LSU Master's Theses

This work features a new approach that is used to measure the rate of plastic work during a cyclic fatigue test, based on the first and second laws of thermodynamics. Using the one-dimensional Fourier heat equation coupled with the concept of fracture fatigue entropy, the rate of plastic work during fatigue can be measured without the need to interrupt a fatigue test, and the accumulated entropy to failure can be quantified. Experimental fatigue tests are conducted on Aluminum 6061-T6 specimens under cyclic axial loading and Carbon Steel 1018 specimens under fully reversed cyclic bending loading. The obtained results in addition …

Modern Lakeshore Processes And Historic Lake And Glacial Changes In Taylor Valley, Antarctica, Michael Stanley Stone

LSU Doctoral Dissertations

Taylor Valley, which opens to the Ross Sea, is one of several ice-free valleys comprising the McMurdo Dry Valleys, Antarctica. The valley is home to several close-basin, perennially ice-covered lakes, whose lake levels largely reflect a balance between meltwater inputs and lake ice ablation; both being driven by climate. A dynamic environment exists where the lake ice covers meet the lakeshore, with the ice grounding to the substrate throughout the cold and dark of winter, and melting to form a perimeter of thin-to-no ice around the lake during the summer. These marginal freeze-thaw regions are known as moats. Here, physical, …

Multiscale & Multiphysics Model Of Damage In Lithium-Ion Batteries, Edris Akbari

LSU Doctoral Dissertations

The demand for safer and more reliable lithium-ion batteries (LIBs) in electric vehicles has increased significantly, especially in addressing mechanical failures like internal short circuits (ISCs), which can lead to thermal runaway. This research investigates the mechanical behavior and damage mechanisms in lithium-ion pouch cells through a multiscale and multiphysics approach, focusing on Lithium Nickel Manganese Cobalt Oxide (NMC) and Lithium Iron Phosphate (LFP) batteries.

The study involved quasi-static and dynamic mechanical tests, including indentation and high-speed penetration, to evaluate stress-strain responses and fracture behaviors. Anisotropic mechanical properties were measured for individual battery components (anode, cathode, separator, and shell) using …

Martial Spirits And Marital Rites: Assessing Rousseau's Critique Of Commerce's Devaluation Of The Military And The Family, Jacob A. Harvey

LSU Doctoral Dissertations

This dissertation will investigate Rousseau’s critique of how commercial society devalues soldiers and families and the responses provided by defenders of commerce. I will examine Rousseau’s corpus to demonstrate how Rousseau viewed commerce as a threat to both the responsibilities that men in a political community must be willing to fight and die for their country, as commercial societies intensify the hedonistic risk-averse calculations within members of the community. I will also show how Rousseau’s concerns towards commerce extended to the family, inhibiting the joys that can come with being part of a family and inhibiting citizens' willingness to have …

Pricing Variance Swaps For The Discrete Bn-S Model, Semere Gebresilasie

Journal of Stochastic Analysis

No abstract provided.

Advancing Data-Driven Disaster Debris Characterization And Quantification, Jasmine Bekkaye

LSU Doctoral Dissertations

Natural hazards generate tremendous amounts of debris that negatively impact communities and overwhelm waste management infrastructure. The challenge in disaster debris planning and management stems from inconsistent and scarce post-disaster debris quantity data due to the chaotic nature of recovery operations. This leads to a limited understanding of key factors influencing disaster debris generation across hazards and regions, hindering the accuracy and efficiency of modeling. With the increasing availability of comprehensive post-disaster waste datasets, the capacity to understand debris generation is expanding. This dissertation aims to fill knowledge gaps on disaster debris generation as follows: (1) investigate existing technologies for …

Rootzone Soil Moisture Dynamics Using Terrestrial Water-Energy Coupling, Vinit Sehgal, Binayak P. Mohanty, Rolf H. Reichle

Faculty Publications

A lack of high-density rootzone soil moisture (θRZ) observations limits the estimation of continental-scale, space-time contiguous θRZ dynamics. We derive a proxy of daily θRZ dynamics — active rootzone degree of saturation (SRZ) — by recursive low-pass (LP) filtering of surface soil moisture (θS) within a terrestrial water-energy coupling (WEC) framework. We estimate the LP filter parameters and WEC thresholds for the piecewise-linear coupling between SRZ and evaporative fraction (EF) at remote sensing and field scale over the Contiguous U.S. We use θS from the Soil Moisture Active-Passive (SMAP) satellite and 218 in-situ stations, with EF from the Moderate Resolution …

The Role Of Benthic Fluxes In Acidifying The Bottom Waters In The Northern Gulf Of Mexico Hypoxic Zone Based On An Updated Water Column Biogeochemical-Seabed Diagenetic And Sediment Transport Model, Dongxiao Yin, Linlin Cui, Courtney K. Harris, Julia M. Moriarty, Hannah Beck, Kanchan Maiti

Faculty Publications

The seabed and the water column are tightly coupled in shallow coastal environments. Numerical models of seabed-water interaction provide an alternative to observational studies that require concurrent measurements in both compartments, which are hard to obtain and rarely available. Here, we present a coupled model that includes water column biogeochemistry, seabed diagenesis, sediment transport and hydrodynamics. Our model includes realistic representations of biogeochemical reactions in both seabed and water column, and fluxes at their interface. The model was built on algorithms for seabed-water exchange in the Regional Ocean Modeling System and expanded to include carbonate chemistry in seabed. The updated …

Workplace Bullying In Louisiana Academic Libraries: Exploring Worker Status And Demographics, Justin Savage, Andrea Hebert, Catherine Baird

Faculty Publications

Bullying is a phenomenon that exists across cultures, societies, and even species. It can be found everywhere, including the workplace. The present study investigates workplace bullying amongst an approximated census sample of Louisiana academic library workers. Using the Negative Acts Questionnaire—Revised (NAQ-R), the study explores the relationships between experiencing workplace bullying and librarian status, tenure status, years in the profession, age, gender, and race. Although no statistically significant relationships were found between variables, the findings add to a growing body of literature that explores the interrelations of demographic and environmental contexts and bullying experiences.