Digital Commons Network^™

Free-Radical Polymerization Of Acid-Containing Deep Eutectic Solvents, Kylee Fazende

LSU Doctoral Dissertations

The forefront of this study explored polymerization, specifically thermally-initiated, free-radical frontal polymerization of (meth)acrylic acid monomers while the monomers acted as a hydrogen bond donor of a deep eutectic solvent. These frontal polymerizations were shown to exhibit unusual front velocities and, in some cases, lower front temperatures than the frontal polymerization of the neat monomers or systems containing inert analogs in the place of the hydrogen bond acceptor of these monomer-containing deep eutectic solvents. The frontal polymerization will occur with a range of initiator concentrations including ones that were too low for the pure monomer systems to sustain a front. …

A Narrative And Performative Methodology For Understanding Adolescent Cancer Stories, Patrick Mcelearney

LSU Doctoral Dissertations

The field of health communication places considerable attention on coping with cancer, typically using social scientific approaches to investigate uncertainty, information, and/or social networks. Social scientific models of coping with adolescent cancer often measure how behaviors seek to manage cancer’s uncontrollability and/or uncertainty; however, how adolescents cope with cancer has been unclear. Short-term studies show adolescents typically and atypically cope. Long-term studies show a significant portion of survivors exhibit post-traumatic stress. The narrative and performative turns expose the role narratives and performatives play in shaping human subjects as meaning makers rather than merely information sharers. A narrative subject reframes cancer’s …

Experimental, Analytical, And Numerical Evaluation Of The Mechanical Properties Of The Brain Tissue, Aref Samadidooki

LSU Doctoral Dissertations

A true understanding of the mechanisms behind most of the brain diseases is still out of reach. For several years, the interest of scientists has been focused on the genetic and biological causes, however, recent studies unraveled the importance of the biomechanics of the brain growth, folding, impact resistance, and deformation on its pathological conditions. While, a wide range of different methods have been used for characterization of the mechanical properties of the brain at the tissue level, the obtained results from different studies are extremely scattered and sometimes in contrast to one another. Since the brain tissue is extremely …

Examining The Sex Ratio In Autism Spectrum Disorder, Maya N. Matheis

LSU Doctoral Dissertations

The higher prevalence of autism spectrum disorder (ASD) among males compared to females is well documented but poorly understood. The ASD sex ratio may provide valuable insight into the underlying neurobiological mechanisms of the disorder. A review of studies examining the prevalence in ASD published in the last 5 years was conducted, revealing a mean male/female (M/F) ratio of 4. Literature examining the ASD sex ratio in relation to risk factors and associated features of ASD was also summarized. The study aimed to examine the ASD sex ratio and its association to various risk factors among an early intervention sample. …

Development Of A Slab-Based Monte Carlo Proton Dose Algorithm With A Robust Material-Dependent Nuclear Halo Model, John Wesley Chapman Jr

LSU Doctoral Dissertations

Pencil beam algorithms (PBAs) are often utilized for dose calculation in proton therapy treatment planning because they are fast and accurate under most conditions. However, as discussed in Chapman et al (2017), the accuracy of a PBA can be limited under certain conditions because of two major assumptions: (1) the central-axis semi-infinite slab approximation; and, (2) the lack of material dependence in the nuclear halo model. To address these limitations, we transported individual protons using a class II condensed history Monte Carlo and added a novel energy loss method that scaled the nuclear halo equation in water to arbitrary geometry. …

Tetrafluorobenzo-Fused Bodipy: A Platform For Regioselective Synthesis Of Bodipy Dye Derivatives, Andrea Savoldelli, Qianli Meng, Roberto Paolesse, Frank R. Fronczek, Kevin M. Smith, M. Graça H. Vicente

Faculty Publications

© 2018 American Chemical Society. A novel route for the synthesis of unsymmetrical benzo-fused BODIPYs is reported using 4,5,6,7-tetrafluoroisoindole as a precursor. The reactivity of the 3,5-dibromo tetrafluorobenzo-fused BODIPY was investigated under nucleophilic substitution and Pd(0)-catalyzed cross-coupling reaction conditions. In addition to the 3,5-bromines, one α-fluoro group on the benzo-fused ring can also be functionalized, and an unusual homocoupling with formation of a bisBODIPY was observed. This new class of fluorinated BODIPYs could find various applications in medicine and materials.

Contribution Of Benthic Processes To The Growth Of Ooids On A Low-Energy Shore In Cat Island, The Bahamas, Giulio Mariotti, Sara B. Pruss, Roger E. Summons, Sharon A. Newman, Tanja Bosak

Faculty Publications

Ooids are typically found in frequently reworked coastal sediments, and are thought to accrete by inorganic chemical precipitation around moving grains. The high organic content and the presence of biosignatures, however, suggest that ooids interact with benthic microbial communities. Here, we investigate the role of benthic processes on ooid growth on a leeward shore of Cat Island, The Bahamas. Polished ooids are present in the surf zone, whereas dull ooids and grapestones are present in microbially colonized sediments seaward of the surf zone. Wave hydrodynamics and sediment transport modeling suggest that microbially colonized sediments are mobilized at monthly time scales. …

Investigating Elearning Continuance Through Expectation Disconfirmation Theory, Susana Reyes Lee

LSU Doctoral Dissertations

This study set out to investigate the Continuing Professional Development (CPD) eLearning participation and completion phenomenon of learners and to explore motivation of CPD eLearning intentions and completions. This study focused on why learners choose CPD eLearning and why they continue in CPD eLearning. Based on the Expectations Disconfirmation theory (EDT) and the DeLone and McLean Information Systems Success Model (1992), a survey was developed and then sent to a cross-section of registered CPD eLearners from the first responder community. After the data was collected 217 responses were analyzed with SPSS correlational techniques and through PROCESS which is a modeling …

Visualization And Quantification Of Cancer-Associated Enzymes With Fluorescent Small-Molecule Substrate Probes, Zhenhua Shen

LSU Doctoral Dissertations

Fluorescence imaging can be used both as a tool to diagnose diseases and guide treatment in clinical settings, and as a technique to monitor dynamic events or biological species in basic research. Therefore, there is a great need for the development of a multitude of fluorescent probes that can be incorporated with fluorescence imaging techniques to track and report endogenous enzymes with high specificity and selectivity. In contrast to always-on and targeted always-on fluorescent probes that continually emit light, activity-based substrate probes either emit low numbers of photons or are completely quenched. They can be converted to highly fluorescent reporters …

Spatial Trends And Variability Of Marsh Accretion Rates In Barataria Basin, Louisiana, Usa Using 210pb And 137cs Radiochemistry, Samuel Bryant Shrull

LSU Master's Theses

Coastal Louisiana is presently experiencing large amounts of coastal land loss with estimated rates exceeding 50 km² lost per year. In an attempt to mitigate or reverse land loss, billions of dollars are earmarked for restoration projects that promote land reclamation, habitat stabilization, and defending against saline intrusion. This study was performed in an effort to better understand spatial trends of accretion rates in Barataria Basin in coastal Louisiana. Data for this project came from twenty-five shallow cores extracted over a broad span of the entire basin, from freshwater to saline environments. Cores were processed for ¹³⁷Cs and …

Essays On The Impact Of Parents' Investment And School Curriculum On Educational Outcomes In China, Han Yu

LSU Doctoral Dissertations

This dissertation consists of two essays studying how students’ educational outcomes are affected by parents’ investment and school curriculum, which are two of the most important determinants of students’ educational performance, respectively. Specifically, in chapter 2, I investigate whether Chinese children born in the auspicious years of Dragon perform better than their comparable peers in school. Using three recently collected datasets from China, I find that students born in the years of the Dragon indeed outperformed their peers in study. I furtherly test the possible mechanisms for the better performance of the “Dragons” in school. The results suggest that parents’ …

Children With Adha Or Anxiety Disorders: Are Common Or Specific Variables Associated With Decreased Performance On Intelligence Indices?, Franziska Noacklesage

LSU Doctoral Dissertations

Although overall psychopathology has been linked to lower intellectual functioning, research has yet to investigate whether one or multiple specific underlying symptom clusters significantly correlate with working memory (WM) and processing speed (PS) deficits. The current study investigated these relationships as they apply to Attention-Deficit/Hyperactivity Disorder (ADHD) and anxiety disorders. As such, one goal of this study was to investigate the extent to which common and specific symptom clusters would predict ADHD and anxiety diagnoses compared to a control group when PS and WM were partialled out. A further goal was to determine if one could differentially predict ADHD from …

The 1987-1989 Phytoplankton Bloom In Kaneohe Bay, Edward Laws, Satoru Taguchi

Faculty Publications

A remarkable bloom of phytoplankton occurred in the southeast sector (SE) of Kaneohe Bay from 1987 through 1989. During the bloom, concentrations of chlorophyll a at the former site of the Kaneohe municipal wastewater treatment plant outfall averaged a little more than 2 mg m^-3 for a period of 40 months. The increase of chl a was accompanied by a roughly twofold increase in the percentage of chl a accounted for by cells retained on a 35-micron filter, a drawdown of silicate concentrations from roughly 10 μM to 3-4 μM, an increase of nitrate concentrations from roughly 0.5 to …

Evaluation Of Microbial Safety And Quality Of Louisiana Strawberries After Flooding, Shifa Shiraz

LSU Master's Theses

Rainfall and flooding have impacted the strawberry industry in Louisiana. Floodwater is an ideal medium for microbiological growth and may cause contamination of soil, agricultural water, and fresh produce with foodborne pathogens. This research aimed to evaluate the microbial safety and quality of strawberries after flooding. Three strains of generic Escherichia coli were used to establish a baseline population of approximately 10⁶ CFU/L (high contamination) and 10² CFU/L (low contamination) in floodwater. Five raised beds were filled with water to simulate a flooding event. Simulated floodwater was mixed with cow manure and spiked with generic E. coli then …

Dynamics Of Phospholipid Membranes Beyond Thermal Undulations, Sudipta Gupta, Judith U. De Mel, Rasangi M. Perera, Piotr Zolnierczuk, Markus Bleuel, Antonio Faraone, Gerald J. Schneider

Faculty Publications

© 2018 American Chemical Society. We investigated the molecular dynamics of unilamellar liposomes by neutron spin echo spectroscopy. We report the first experimental evidence of a short-range motion at the length scale of the size of the headgroup of a lipid. The associated mean squared displacement shows a t0.26 dependence in the pico- to nanosecond region that indicates another process beyond the predictions of the Zilman-Granek (ZG) model (t0.66) and translational diffusion (t1). A comparison with theory shows that the observed low exponent is associated with a non-Gaussian transient trapping of lipid molecules in a local area and supports the …

Neighbor And Height Effects On Crown Properties Associated With The Uniform-Stress Principle Of Stem Formation, Thomas J. Dean

Faculty Publications

According to the uniform-stress principle of stem formation, the amount of leaf area a tree carries and the leverage it exerts on the stem determine the stem dimensions. Within an even-aged monoculture, the leaf area per tree and the leverage placed on the stem are functions of tree density and tree height. The uniform-stress principle presents the means to translate density effects on crown characteristics into stem dimensions and total standing volume. This approach is truly a top-down method of simulating growth tree and stand growth because leaf area and other crown properties must be determined before stem size and …

Glyphosate In Soils: Retention, Transport, And Effect Of Phosphate, Joshua Padilla

LSU Master's Theses

Glyphosate [N-(phosphonomethyl) glycine)] (GPS) is currently the most commonly used herbicide worldwide, and is generally considered as immobile in soils. However, numerous reports of the environmental occurrence of the herbicide coupled with recent evidence of human toxicity require further investigation as to the behavior of GPS in the soil environment. The objectives of this study were to quantify GPS sorption and mobility in two Louisiana agricultural soils with varying physiochemical properties; Commerce silt loam and Sharkey clay. Results of batch sorption studies indicated a high affinity of both soils for solvated GPS, with 24-hour Freundlich partitioning coefficients of 158 and …

A Comparison Of Causal Inference Methods And Their Application In Big Data Analytics, Xuan Wang

LSU Doctoral Dissertations

With the rise of Big Data analytics, the new field of causal inference (Pearl, 2009) has received more attention in business research fields such as Accounting (Lawrence, Minutti-Meza, & Zhang, 2011) and Marketing (Manganaris, Bhasin, Reid, & Hermiz Keith, 2010). Traditional statistics focuses on correlation which may lead to misleading conclusions because the estimates can be severely biased even when data sets are large. The objective of causal inference is to obtain estimates from observational data that are unbiased and can thus be interpreted as causal. This study provides a systematic comparison of the performance of four causal inference methods …

Assessing Pyrite-Derived Sulfate In The Mississippi River With Four Years Of Sulfur And Triple-Oxygen Isotope Data, Bryan A. Killingsworth, Huiming Bao, Issaku E. Kohl

Faculty Publications

© 2018 American Chemical Society. Riverine dissolved sulfate (SO42-) sulfur and oxygen isotope variations reflect their controls such as SO42- reduction and reoxidation, and source mixing. However, unconstrained temporal variability of riverine SO42- isotope compositions due to short sampling durations may lead to mischaracterization of SO42- sources, particularly for the pyrite-derived sulfate load. We measured the sulfur and triple-oxygen isotopes (δ34S, δ18O, and Δ′17O) of Mississippi River SO42- with biweekly sampling between 2009 and 2013 to test isotopic variability and constrain sources. Sulfate δ34S and δ18O ranged from -6.3‰ to -0.2‰ and -3.6‰ to +8.8‰, respectively. Our sampling period captured …

Assessing Pyrite-Derived Sulfate In The Mississippi River With Four Years Of Sulfur And Triple-Oxygen Isotope Data, Bryan A. Killingsworth, Huiming Bao, Issaku E. Kohl

Faculty Publications

© 2018 American Chemical Society. Riverine dissolved sulfate (SO42-) sulfur and oxygen isotope variations reflect their controls such as SO42- reduction and reoxidation, and source mixing. However, unconstrained temporal variability of riverine SO42- isotope compositions due to short sampling durations may lead to mischaracterization of SO42- sources, particularly for the pyrite-derived sulfate load. We measured the sulfur and triple-oxygen isotopes (δ34S, δ18O, and Δ′17O) of Mississippi River SO42- with biweekly sampling between 2009 and 2013 to test isotopic variability and constrain sources. Sulfate δ34S and δ18O ranged from -6.3‰ to -0.2‰ and -3.6‰ to +8.8‰, respectively. Our sampling period captured …

Role Of Neutrophils In The Modulation Of Host Responses To Human Respiratory Pneumovirus Infection, Nagarjuna Reddy Cheemarla

LSU Doctoral Dissertations

Neutrophils are the most abundant leukocytes (50% to 70%) in humans and are the first immune cell population recruited to the sites of infection. They are known to act as the first line of innate immune defense against invading pathogens, and more recently, to playing a crucial role in orchestrating adaptive immune responses. The role of neutrophils in the respiratory viral infections till date remains unclear and controversial. Previous studies demonstrated both beneficial as well as pathogenic role for neutrophils in respiratory viral infections, especially influenza.

Previous findings reported an early and high influx of neutrophils into the airways early …

Shifting Niche Space In Coastal Landscapes: Spatio-Temporal Patterns Driving Submerged Aquatic Vegetation Across The Northern Gulf Of Mexico, Kristin Elise Demarco

LSU Doctoral Dissertations

Identifying distributions of submerged aquatic vegetation (SAV) across the northern Gulf of Mexico (NGOM) coastal landscape necessitates describing ecological processes in estuarine gradients. SAV assemblages are ecological indicators of aquatic ecosystem health; spatial and temporal distributions are strongly correlated to environmental conditions. Many wildlife species, including waterfowl, are dependent on SAV and seeds in NGOM coastal marshes for food and habitat. To understand SAV distributions at multiple spatial and temporal scales a multi-tiered project was designed to collect SAV presence, species assemblage, and cover data, and cores to describe seed food. The first tier sampled inter-annually in the growing seasons …

Species Richness And Phylogenetic Diversity Of Native And Non-Native Species Respond Differently To Area And Environmental Factors, Daijiang Li, William B. Monahan, Benjamin Baiser

Faculty Publications

© 2018 John Wiley & Sons Ltd Aim: To test whether native and non-native species have similar diversity–area relationships (species–area relationships [SARs] and phylogenetic diversity–area relationships [PDARs]) and whether they respond similarly to environmental variables. Location: United States. Methods: Using lists of native and non-native species as well as environmental variables for >250 US national parks, we compared SARs and PDARs of native and non-native species to test whether they respond similarly to environmental conditions. We then used multiple regressions involving climate, land cover and anthropogenic variables to further explore underlying predictors of diversity for plants and birds in US …

Intraspecific Variation In Indirect Plant–Soil Feedbacks Influences A Wetland Plant Invasion, Warwick J. Allen, Laura A. Meyerson, Andrew J. Flick, James T. Cronin

Faculty Publications

© 2018 by the Ecological Society of America Plant–soil feedbacks (PSFs) influence plant competition via direct interactions with pathogens and mutualists or indirectly via apparent competition/mutualisms (i.e., spillover to co-occurring plants) and soil legacy effects. It is currently unknown how intraspecific variation in PSFs interacts with the environment (e.g., nutrient availability) to influence competition between native and invasive plants. We conducted a fully crossed multi-factor greenhouse experiment to determine the effects of Phragmites australis rhizosphere soil biota, interspecific competition, and nutrient availability on biomass of replicate populations from one native and two invasive lineages of common reed (P. australis) and …

Generating Dna Sequence Data With Limited Resources For Molecular Biology: Lessons From A Barcoding Project In Indonesia, Gillian H. Dean, Rani Asmarayani, Marlina Ardiyani, Yessi Santika, Teguh Triono, Sarah Mathews, Campbell O. Webb

Faculty Publications

Applications in Plant Sciences is published by Wiley Periodicals, Inc. on behalf of the Botanical Society of America The advent of the DNA sequencing age has led to a revolution in biology. The rapid and cost-effective generation of high-quality sequence data has transformed many fields, including those focused on discovering species and surveying biodiversity, monitoring movement of biological materials, forensic biology, and disease diagnostics. There is a need to build capacity to generate useful sequence data in countries with limited historical access to laboratory resources, so that researchers can benefit from the advantages offered by these data. Commonly used molecular …

Advancing Dendrochronological Studies Of Fire In The United States, Grant L. Harley, Christopher H. Baisan, Peter M. Brown, Donald A. Falk, William T. Flatley, Henri D. Grissino-Mayer, Amy Hessl, Emily K. Heyerdahl, Margot W. Kaye, Charles W. Lafon, Ellis Q. Margolis, R. Stockton Maxwell, Adam T. Naito, William J. Platt, Monica T. Rother, Thomas Saladyga, Rosemary L. Sherriff, Lauren A. Stachowiak, Michael C. Stambaugh, Elaine Kennedy Sutherland, Alan H. Taylor

Faculty Publications

© 2018 by the authors. Licensee MDPI, Basel, Switzerland. Dendroecology is the science that dates tree rings to their exact calendar year of formation to study processes that influence forest ecology (e.g., Speer 2010 [1], Amoroso et al., 2017 [2]). Reconstruction of past fire regimes is a core application of dendroecology, linking fire history to population dynamics and climate effects on tree growth and survivorship. Since the early 20th century when dendrochronologists recognized that tree rings retained fire scars (e.g., Figure 1), and hence a record of past fires, they have conducted studies worldwide to reconstruct [2] the historical range …

Taxonomy Of Calophya (Hemiptera: Calophyidae) Species Associated With Schinus Terebinthifolia (Anacardiaceae), Daniel Burckhardt, James P. Cuda, Rodrigo Diaz, William Overholt, Patricia Prade, Dalva Luiz De Queiroz, Marcelo D. Vitorino, Gregory S. Wheeler

Faculty Publications

© 2018 Florida Entomological Society. All rights reserved. Brazilian peppertree, Schinus terebinthifolia Raddi (Anacardaceae), native to Argentina, Brazil, Paraguay, and Uruguay, is one of the most invasive weeds in Florida. In its native range, at least 4 psyllid species of the genus Calophya (Hemiptera: Calophyidae) are associated with it. All 4 species are monophagous and constitute a likely monophyletic group that induce pit galls, usually on the upper leaf surface. Here we revise the taxonomy of these species, 2 of which are described as new, viz. C. lutea sp. nov. and C. praestigiator sp. nov. Morphological differences between the 4 …

Structural Modification Of The Tripeptide Kpv By Reductive “Glycoalkylation” Of The Lysine Residue, Abigael C. Songok, Pradip Panta, William T. Doerrler, Megan A. Macnaughtan, Carol M. Taylor

Faculty Publications

© 2018 Songok et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Peptides that exhibit enzymatic or hormonal activities are regulatory factors and desirable therapeutic drugs because of their high target specificity and minimal side effects. Unfortunately, these drugs are susceptible to enzymatic degradation, leading to their rapid elimination and thereby demanding frequent dosage. Structurally modified forms of some peptide drugs have shown enhanced pharmacokinetics, improving their oral bioavailability. Here, we discuss a …

Structural Modification Of The Tripeptide Kpv By Reductive “Glycoalkylation” Of The Lysine Residue, Abigael C. Songok, Pradip Panta, William T. Doerrler, Megan A. Macnaughtan, Carol M. Taylor

Faculty Publications

© 2018 Songok et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Peptides that exhibit enzymatic or hormonal activities are regulatory factors and desirable therapeutic drugs because of their high target specificity and minimal side effects. Unfortunately, these drugs are susceptible to enzymatic degradation, leading to their rapid elimination and thereby demanding frequent dosage. Structurally modified forms of some peptide drugs have shown enhanced pharmacokinetics, improving their oral bioavailability. Here, we discuss a …

Groundsel Bush (Baccharis Halimifolia) Extract Promotes Adipocyte Differentiation In Vitro And Increases Adiponectin Expression In Mature Adipocytes, Anik Boudreau, Scott Fuller, Davidm Ribnicky, Allison J. Richard, Jacqueline M. Stephens

Faculty Publications

© 2018 by the authors. Licensee MDPI, Basel, Switzerland. An ethanolic extract of Baccharis halimifolia (groundsel bush, GB), which is a native Louisiana plant with documented use in Creole folk medicine, has been shown to inhibit lipopolysaccharide (LPS)-induced inflammation in cultured macrophages. Here, we examine the effects of GB on adipocyte development and function, as these processes are attractive targets for intervention in insulin resistance. Oil Red O neutral lipid staining, reverse transcription-quantitative polymerase chain reaction (RT-qPCR), and immunoblotting were used to measure GB effects on lipid accumulation, gene expression, and protein abundance, respectively. In differentiating 3T3-L1 adipocytes, GB enhanced …