Digital Commons Network^™

Microplastics In Mainstem Mississippi River Fishes, Ahmed K. Gad, Kerrin Toner, Mark C. Benfield, Stephen R. Midway

Faculty Publications

Microplastics are ubiquitous in Earth’s ecosystems and many efforts have begun to understand their distributions. Large rivers, like the Mississippi River, provide a unique system in which to look at large-scale patterns of microplastic distribution. In this study, we sampled four species of widely-distributed fishes from five sites along the mainstem Mississippi River, from Minnesota to Louisiana, United States. Microplastics were found in all fish species and at all sites; however, microplastics increased in occurrence in the Lower Mississippi River. Fragments were the most common morphologies and polypropylene was the most common polymer detected. We also examined the hypothesis that …

Editorial: Abiotic Stress: Molecular Genetics And Genomics, Volume Ii, Rohini Garg, Prasanta K. Subudhi, Rajeev K. Varshney, Mukesh Jain

Faculty Publications

No abstract provided.

Dual Targeting Of Mtor/Il-17a And Autophagy By Fisetin Alleviates Psoriasis-Like Skin Inflammation, Tithi Roy, Sergette Banang-Mbeumi, Samuel T. Boateng, Emmanuelle M. Ruiz, Roxane Cherille N. Chamcheu, Lin Kang, Judy A. King, Anthony L. Walker, Bolni Marius Nagalo, Konstantin G. Kousoulas, Stephane Esnault, Shile Huang, Jean Christopher Chamcheu

Faculty Publications

Psoriasis is a chronic autoimmune inflammatory skin disorder characterized by epidermal hyperplasia and aberrant immune response. In addition to aberrant cytokine production, psoriasis is associated with activation of the Akt/mTOR pathway. mTOR/S6K1 regulates T-lymphocyte activation and migration, keratinocytes proliferation and is upregulated in psoriatic lesions. Several drugs that target Th1/Th17 cytokines or their receptors have been approved for treating psoriasis in humans with variable results necessitating improved therapies. Fisetin, a natural dietary polyphenol with anti-oxidant and anti-proliferative properties, covalently binds mTOR/S6K1. The effects of fisetin on psoriasis and its underlying mechanisms have not been clearly defined. Here, we evaluated the …

Anaerobic Toluene Biodegradation Potential At A Superfund Site Where Toluene Biosynthesis Was Observed, George Carson

LSU Master's Theses

At a Superfund site near Baton Rouge, LA, the subsurface injection of molasses has been used to stimulate anerobic reductive dechlorination of halogenated organic compounds (e.g., 1,2-dichloroethane and vinyl chloride) present in the groundwater. Following some molasses injections, temporary accumulation of toluene and p-cresol was observed in the groundwater. Accumulation of these aromatic hydrocarbons, which were not detected in the molasses, has been attributed to anaerobic biotransformation of the amino acids phenylalanine and tyrosine. Experiments reported here were conducted in support of an effort to determine if toluene biodegrading bacteria were present in the area where anaerobic toluene accumulation was …

Data-Driven Nonparametric Joint Chance-Constrained Programming For Power Systems Scheduling, Chutian Wu

LSU Doctoral Dissertations

This dissertation is dedicated to implementing data-driven nonparametric joint chance constraints (JCC) to power system optimization problems. Power generated by renewable sources, such as solar farms, is an uncertain parameter. Several approaches solve optimization under uncertainty, including stochastic programming, robust programming, and chance-constrained programming. Uncertain parameters may not belong to any parametric class of probability functions. Thus, methods that consider such uncertainty as a random variable that fits in a known probability density function (PDF) have limitations. This study focuses on chance-constrained programming under nonparametric or data-driven distributionally robust uncertainty settings.

Studies based on chance-constrained programming usually focus on individual …

Explanation Needed: Understanding The Low Graduation Rates Of Spanish-Speaking English Learners In Southeastern Louisiana, Alice I. Garcia

LSU Doctoral Dissertations

This qualitative research study used the case study method of one-on-one interviews to collect and examine the experiences of former English learners (ELs) who were unable to finish high school in southeastern Louisiana. This study aimed to identify specific factors that, using Everett Lee’s theory, pushed or pulled these ELs from school and affected their ability to graduate. The push factors that were identified included language, inadequate support, academic performance, discrimination, and lack of connection with school and culture. Pull factors that were identified included lack of prior education, immigration, poverty, pregnancy, being far from family, financially supporting family, and …

Effect Of Bovine Oocyte Vitrification With Egta And Post-Warming Recovery With Resveratrol On Meiotic Spindle, Mitochondrial Function, Reactive Oxygen Species, And Developmental Competence, Emilio Gutierrez-Castillo, Fabian A. Diaz, Sydney A. Talbot, Kenneth R. Bondioli

Faculty Publications

The present study aimed to determine the effects of the addition of EGTA to vitrification solutions and a post-warming recovery period supplemented with 1 μM resveratrol on meiotic spindle integrity, mitochondrial activity, ATP content, reactive oxygen species (ROS) levels, and developmental potential of partially denuded, vitrified-warmed bovine oocytes. Results of microtubule distribution and chromosomal arrangement indicated that resveratrol supplementation, irrespective to EGTA addition, reduced the incidence of abnormal meiotic spindles to similar levels of the control group. Mitochondrial membrane potential was similar in all groups, but ATP content was negatively affected by the vitrification-warming procedure and failed to recover after …

Response Of Marginal Height Costs And Marginal Height Benefits To Competition, Thomas J. Dean, Constance A. Harrington, Anthony D'Amato, Brian J. Palik

Faculty Publications

Height growth in trees is expensive in terms of the amount of stem tissue required to maintain productive tissue in sunlight. However, shifting allocation from stem support to leader growth and foliage production may allow trees to minimize shading effects on photosynthesis, especially for shorter trees within the population. This hypothesis was evaluated with data collected in competition studies for red alder (Alnus rubra Bong.), Douglas-fir (Pseudotsuga menziesii var. menziesii [Mirb.] Franco), and red pine (Pinus resinosa Ait.). Stem allocation per unit height growth was defined as a marginal height cost, and foliage added per unit height growth was defined …

A Forestry Trade Data Discrepancy Analysis, Morgan Alyce Daigle

LSU Master's Theses

Trade data across multiple databases experience unavailability across some countries/forestry products, inconsistency, and unreliability; and these qualities manifest as discrepancies in the data. Literature provides evidence of discrepancies and inconsistencies within international trade statistics, including documented cases in which they are present within agriculture sector trade.

While researchers have worked to pinpoint factors to explain discrepancies, studies on the forestry trade databases are not as prevalent. Therefore, more research needs to be conducted to identify discrepancies within forest sector products trade data to understand the nature of discrepancies found between different bilateral trading partners.

The goal of this thesis is …

Introduction To Control Engineering, Xiangyu Meng

E-Textbooks

This is an introductory level textbook for control engineering.

Finding Forensic Evidence In The Operating System's Graphical User Interface, Edward X. Wilson Mr.

LSU Master's Theses

A branch of cyber security known as memory forensics focuses on extracting meaningful evidence from system memory. This analysis is often referred to as volatile memory analysis, and is generally performed on memory captures acquired from target systems. Inside of a memory capture is the complete state of a system under investigation, including the contents of currently running as well as previously executed applications. Analysis of this data can reveal a significant amount of activity that occurred on a system since the last reboot. For this research, the Windows operating system is targeted. In particular, the graphical user interface component …

Media Literacy In Public Education: A Mixed-Method Exploration, Jessica Wyers

LSU Doctoral Dissertations

You have to know where you are to know where you’re going. This is the approach I attempt to take to understand next steps in media literacy education and policy. Little research has been done to understand the current state of media literacy education, what is actually happening in the classrooms and education system, to better judge more intentional interventions in the future.

This dissertation explores the current issues in media literacy education in our public schools. I combine the strengths of a qualitative investigation of published public school media literacy curricula with survey data measuring the perceptions of students’ …

Visual Analytics And Modeling Of Materials Property Data, Diwas Bhattarai

LSU Doctoral Dissertations

Due to significant advancements in experimental and computational techniques, materials data are abundant. To facilitate data-driven research, it calls for a system for managing and sharing data and supporting a set of tools for effective data analysis and modeling. Generally, a given material property M can be considered as a multivariate data problem. The dimensions of M are the values of the property itself, the conditions (pressure P, temperature T, and multi-component composition X) that control the concerned property, and relevant metadata I (source, date).

Here we present a comprehensive database considering both experimental and computational sources …

Contagious Animality: Species, Disease, And Metaphor In Early Modern Literature And Culture, Jeremy Cornelius

LSU Doctoral Dissertations

In my dissertation, Contagious Animality: Species, Disease, and Metaphor in Early Modern Literature and Culture, I close read examples of Renaissance drama alongside their contemporary cultural texts to examine anxieties around social differences as constructed and mediated through what I call “contagious animality” in early modern English culture. Animal metaphors circulated anxieties around social differences on the early modern cultural stage in English drama where animality elicits uncertainties about identitarian constructions of difference. In this vein, I close read formal elements and their interactions with early modern culture to argue that animal metaphors transmit modes of speciating difference in …

Ion Transport On Self-Assembled Block Copolymer Electrolytes With Different Side Chain Chemistries, Mario V. Ramos-Garcés, Dodangodage Ishara Senadheera, Karthik Arunagiri, Polyxeni P. Angelopoulou, Georgios Sakellariou, Ke Li, Bryan D. Vogt, Revati Kumar, Christopher G. Arges

Faculty Publications

Ion-exchange membranes (IEMs) are used in electrochemical systems for a wide variety of applications, including water purification, mineral recovery, and energy storage and conversion. These materials often dictate the ohmic overpotential drop in electrochemical systems and can have a profound impact on process efficiency. Central to the rationale design of ion-conducting polymers is a fundamental understanding as to how chemical composition and macromolecular architecture influence ion and water transport. Herein, we report the preparation of three microphase separated block copolymer electrolytes (BCEs) with long-range order that have different side chain chemistries in the ionic domain. The side chain variants are …

Computational Study Of C-C Coupling Reactions On Heterogeneous Catalysts, Md Saeedur Rahman

LSU Doctoral Dissertations

The utilization of carbon dioxide (CO₂) in chemical production has attracted global research interest. Reacting CO₂ with methane (CH₄) removes these greenhouse gases from the atmosphere and turns both compounds into building blocks for organic compound synthesis. A commonly explored pathway involves dry reforming of methane (DRM), which reacts CH₄ and CO₂ to form syngas, a mixture of H₂ and CO. Syngas is a widely used feedstock for synthesizing chemicals ranging from methanol to fuels via the Fischer-Tropsch (FT) process. However, DRM has a large positive ΔGº, which requires the …

Characterization Of Antiviral Immunity, Host Virus Interactions, And Toxicity Of Agrochemical Residues In The Western Honey Bee, Christopher Fellows

LSU Doctoral Dissertations

Honey bee colonies have perished at an alarming rate for over 15 years. Among the multitude of threats to bee health, virus infections and agrochemical exposure appear to be major drivers of colony loss. As virus infection is among the most damaging influences on bee health, we first investigated a putative target for antiviral immunity, termed K_ATP channels. We previously demonstrated that pharmacologically activating K_ATP channels induces the production of reactive oxygen species and increases survival during infection with Israeli Acute Paralysis Virus. Here, we demonstrate that K_ATP modulation and ROS induction reduce virus replication and enhance …

Prospective Association Of Daily Steps With Cardiovascular Disease: A Harmonized Meta-Analysis, Amanda E. Paluch, Shivangi Bajpai, Marcel Ballin, David R. Bassett, Thomas W. Buford, Mercedes R. Carnethon, Ariel Chernofsky, Erin E. Dooley, Ulf Ekelund, Kelly R. Evenson, Deborah A. Galuska, Barbara J. Jefferis, Lingsong Kong, William E. Kraus, Martin G. Larson, I. Min Lee, Charles E. Matthews, Robert L. Newton, Anna Nordström, Peter Nordström, Priya Palta, Alpa V. Patel, Kelley Pettee Gabriel, Carl F. Pieper, Lisa Pompeii, Erika Rees-Punia, Nicole L. Spartano, Ramachandran S. Vasan, Peter H. Whincup, Shengping Yang, Janet E. Fulton

Population and Public Health Science Faculty Publications

Background: Taking fewer than the widely promoted "10 000 steps per day" has recently been associated with lower risk of all-cause mortality. The relationship of steps and cardiovascular disease (CVD) risk remains poorly described. A meta-analysis examining the dose-response relationship between steps per day and CVD can help inform clinical and public health guidelines. Methods: Eight prospective studies (20 152 adults [ie, ≥18 years of age]) were included with device-measured steps and participants followed for CVD events. Studies quantified steps per day and CVD events were defined as fatal and nonfatal coronary heart disease, stroke, and heart failure. Cox proportional …

Sexual Dimorphism In Corallite Size And Modularity Of A Broadcast Spawning Coral, Porites Lobata, Ricardo M. Pedraza-Pohlenz, Eduardo F. Balart, J. J.Adolfo Tortolero-Langarica, Alma Paola Rodríguez-Troncoso, Michael E. Hellberg, Orión Norzagaray-López, Rafael A. Cabral-Tena, Amílcar Leví Cupul-Magaña, David A. Paz-García

Faculty Publications

Differences in selective pressures and the energetic cost of gametes in gonochoristic corals should vary with the sex of the colony, which may lead to sexual dimorphism. Coral colonies are composed of subunits (corallites) that create a complex morphological architecture. If corallite features are distinct between sexes, then the degree of coordinated change among these subunits may also vary (phenotypic modularity). This study tested for sexual dimorphism in the corallites of the reef-building coral Porites lobata, a gonochoric broadcast spawner, and compared this with previously demonstrated sexual dimorphism in its congener P. panamensis, a gonochoric brooder. Corallite area in P. …

Changing Features Of The Northern Hemisphere 500-Hpa Circumpolar Vortex, Nazla Bushra, Robert V. Rohli, Chunyan Li, Paul W. Miller, Rubayet Bin Mostafiz

Faculty Publications

The tropospheric circumpolar vortex (CPV), an important signature of processes steering the general atmospheric circulation, surrounds each pole and is linked to the surface weather conditions. The CPV can be characterized by its area and circularity ratio (Rc), which both vary temporally. This research advances previous work identifying the daily 500-hPa Northern Hemispheric CPV (NHCPV) area, Rc, and temporal trends in its centroid by examining linear trends and periodic cycles in NHCPV area and Rc (1979–2017). Results suggest that NHCPV area has increased linearly over time. However, a more representative signal of the planetary warming may be the temporally weakening …

Flood Risk Assessment For Residences At The Neighborhood Scale By Owner/Occupant Type And First-Floor Height, Ayat Al Assi, Rubayet Bin Mostafiz, Carol J. Friedland, Md Adilur Rahim, Robert V. Rohli

Faculty Publications

Evaluating flood risk is an essential component of understanding and increasing community resilience. A robust approach for quantifying flood risk in terms of average annual loss (AAL) in dollars across multiple homes is needed to provide valuable information for stakeholder decision-making. This research develops a computational framework to evaluate AAL at the neighborhood level by owner/occupant type (i.e., homeowner, landlord, and tenant) for increasing first-floor height (FFH). The AAL values were calculated here by numerically integrating loss-exceedance probability distributions to represent economic annual flood risk to the building, contents, and use. A simple case study for a census block in …

Expanding Swirl Combustor Operability On Methane-Ammonia-Air Mixtures Using A Distributed Fuel Injection Technique And Inlet Air Preheating, V. Viswamithra, M. Gurunadhan, S. Menon

Faculty Publications

The necessity to reduce greenhouse gas emissions has prompted the search for carbon-free fuel alternatives. One such carbon-free fuel source that can be used for power generation in a gas turbine-based system is ammonia. Ammonia combustion poses challenges due to reduced flame speed and reactivity, which can be alleviated by addition of methane or natural gas. However, NOx emissions continue to be an issue, which needs resolution before practical consideration of ammonia as a fuel source. One of the potential solutions that has been proposed is a two-stage, rich-lean combustion process to minimize NOx while ensuring complete reactant consumption. This …

Mouse Pancreatic Peptide Hormones Probed At The Sub-Single-Islet Level: The Effects Of Acute Corticosterone Treatment, Aleksandra Antevska, Connor C. Long, Samuel D. Dupuy, J. Jason Collier, Michael D. Karlstad, Thanh D. Do

Division of Basic Science Faculty Publications

We combine liquid chromatography coupled with ion mobility spectrometry-mass spectrometry to elucidate how short exposure to corticosterone (Cort) alters the output of mouse pancreatic islet hormones. The workflow enables the robust separation of mouse insulin 1 (Ins1) and insulin 2 (Ins2) and the detection of major islet hormones in a homogenate equivalent to 100-150 islet cells. We show that Ins2 has a unique structure and is degraded much faster than Ins1. Further investigation indicates that Ins2 may populate both T and R states, whereas Ins1 may not. The assemblies of Ins1’s B-chain also introduce more structural heterogeneity than Ins2. Collectively, …

Skinks Of Oceania, New Guinea, And Eastern Wallacea: An Underexplored Biodiversity Hotspot, Alex Slavenko, Allen Allison, Christopher C. Austin, Aaron M. Bauer, Rafe M. Brown, Robert N. Fisher, Ivan Ineich, Bulisa Iova, Benjamin R. Karin, Fred Kraus, Sven Mecke, Shai Meiri, Clare Morrison, Paul M. Oliver, Mark O. Shea, Jonathan Q. Richmond, Glenn M. Shea, Oliver J.S. Tallowin, David G. Chapple

Faculty Publications

Context. Skinks comprise the dominant component of the terrestrial vertebrate fauna in Oceania, New Guinea, and Eastern Wallacea (ONGEW). However, knowledge of their diversity is incomplete, and their conservation needs are poorly understood. Aims. To explore the diversity and threat status of the skinks of ONGEW and identify knowledge gaps and conservation needs. Methods. We compiled a list of all skink species occurring in the region and their threat categories designated by the International Union for Conservation of Nature. We used available genetic sequences deposited in the National Center for Biotechnology Information's GenBank to generate a phylogeny of the region’s …

Measurement Of Near-Threshold Proton Branching Ratios In 31s Important For Novae, Sudarsan Balakrishnan

LSU Doctoral Dissertations

Classical novae are stellar explosions that contribute to the nucleosynthesis of isotopes on the proton-rich side of the valley of stability up to ⁴⁰Ca. In ONe novae, the incompletely understood reaction rate of ³⁰P(p,γ)³¹S is known to strongly influence the production rate of several stable isotopes such as ³⁰Si, ³¹P, and ^32,33,34S. A precise measurement of this reaction rate has several potential implications towards matching astrophysical observables to the physical composition of the nova site -- the observed elemental abundance ratios of O/S and S/Al have been suggested as useful `thermometers' to gauge …

Multilayered Graphene And Methods Of Making The Same, Manas Ranjan Gartia, Ardalan Chaichi

College of Engineering Patents

The present invention relates in part to a method of fabricating graphene structures from graphene oxide by reducing the graphene oxide on a patterned substrate. The invention also relates in part to graphene structures produced using said method and electrodes and capacitors comprising said graphene structures.

Drivers Of Diatom Production And The Legacy Of Eutrophication In Two River Plume Regions Of The Northern Gulf Of Mexico, Jeffrey W. Krause, Adam D. Boyette, Israel A. Marquez, Rebecca A. Pickering, Kanchan Maiti

Faculty Publications

In the northern Gulf of Mexico (nGoM), the Louisiana Shelf (LS) and Mississippi Bight (MB) subregions are influenced by eutrophication to varying degrees. Despite recognition that dissolved silicon may regulate diatom productivity in the nGoM, there is only one published data set reporting biogenic silica (bSiO2) production rates for each subregion. We report that bSiO2 production rates on the LS and MB are high and appear to be controlled by different nutrients among seasons. Despite exceptional upper trophic level biomass regionally, which suggests significant primary production by diatoms (as in other systems), gross euphotic-zone integrated bSiO2 production rates are lower …

Understanding Meteorological Changes Following Severe Defoliation During A Strong Hurricane Landfall: Insights From Hurricane Michael (2018), Shannon A. Nelson, Paul W. Miller

Faculty Publications

Despite prompting persistent meteorological changes, severe defoliation following a tropical cyclone (TC) landfall has received relatively little attention and is largely overlooked within hurricane preparedness and recovery plan-ning. Changes to near-track vegetation can modify evapotranspiration for months after tropical cyclone passage, thereby altering boundary layer moisture and energy fluxes that drive the local water cycle. This study seeks to understand poten-tial spatial and temporal changes in defoliation-driven meteorological conditions using Hurricane Michael (2018) as a testbed. In this sensitivity study, two Weather Research and Forecasting (WRF) Model simulations, a normal-landscape and a post-TC scenario, are compared to determine how a …

Dissolved Organic Carbon Dynamics And Fluxes In Mississippi-Atchafalaya Deltaic System Impacted By An Extreme Flood Event And Hurricanes: A Multi-Satellite Approach Using Sentinel-2/3 And Landsat-8/9 Data, Bingqing Liu, Eurico J. D’Sa, Francesca Messina, Melissa M. Baustian, Kanchan Maiti, Victor H. Rivera-Monroy, Wei Huang, Ioannis Y. Georgiou

Faculty Publications

Transport of riverine and wetland-derived dissolved organic carbon (DOC) spanning tidal wetlands, estuaries, and continental shelf waters functionally connects terrestrial and aquatic carbon reservoirs, yet the magnitude and ecological significance of this variable and its spatiotemporal linkage remains uncertain for coastal deltaic regions, such as Mississippi River Delta Plain, which includes Mississippi (MR) and Atchafalaya (AR) rivers and estuaries with vast expanses of wetlands and coastal forests. We examined DOC dynamics and fluxes in this large river-dominated wetland-estuarine system for the period between 2019 and 2021 that included an extreme river flood event in 2019, two major hurricanes (Barry in …

Sudden Reduction Of Antarctic Sea Ice Despite Cooling After Nuclear War, Joshua Coupe, Cheryl Harrison, Alan Robock, Alice Duvivier, Elizabeth Maroon, Nicole S. Lovenduski, Scott Bachman, Laura Landrum, Charles Bardeen

Faculty Publications

A large-scale nuclear war could inject massive amounts of soot into the stratosphere, triggering rapid global climate change. In climate model simulations of nuclear war, global cooling contributes to an expansion of sea ice in the Northern Hemisphere. However, in the Southern Hemisphere (SH), an initial expansion of sea ice shifts suddenly to a 30% loss of sea ice volume over the course of a single melting season in the largest nuclear war simulation. In smaller nuclear war simulations an expansion in sea ice is instead observed which lasts for approximately 15 years. In contrast, in the largest nuclear war …