Digital Commons Network^™

Quantifying Impacts Of Climate Change On Species Interactions While Fostering Undergraduate Research Experiences Using The Monarch (Danaus Plexippus)- Milkweed (Asclepias Sp.) System, Matthew J. Faldyn

LSU Doctoral Dissertations

Species interactions, specifically plant-insect interactions, are ubiquitous worldwide. Climate change will alter species interactions by affecting abiotic conditions, affecting species phenologies, interaction strengths, and physiological development. However, climate change impacts are often studied using individual species, with limited consideration quantifying the direct and indirect impacts of climate change species interactions. Using lab, field, and greenhouse experiments, I investigated how climate change will directly and indirectly affect species interactions while also fostering undergraduate research experiences using the monarch butterfly (Danaus plexippus)- milkweed (Asclepias sp.) system.

In North America, a widely planted, invasive milkweed species, Asclepias curassavica, negatively …

Multiphase Cfd Modeling In Particle-Laden Flows, Zhizhong Ding

LSU Doctoral Dissertations

Multiphase modeling is prevalent and useful in solving problems involving multiphase interactions such as fluid and solid. Applications conclude but not limited to fluidized bed, hydraulic conveying, and many others. Modeling techniques with multiple scales can provide various states of details with diverse computational resources used. In this dissertation, two CFD multiphase models are used to disclose interaction details in the particulate system. Two-Fluid Model is used to solve pulsed fluidized bed problem and immersed boundary method based direct numerical method is used to solve particle’s behavior in shear flow. Getting a better understanding of these problems to help to …

Phase-Field Study Of Crack Nucleation And Propagation In Elastic–Perfectly Plastic Bodies, Stella Brach, Erwan Tanné, Blaise Bourdin, Kaushik Bhattacharya

Faculty Publications

Crack initiation and propagation in elastic–perfectly plastic bodies is studied in a phase-field or variational gradient damage formulation. A rate-independent formulation that naturally couples elasticity, perfect plasticity and fracture is presented, and used to study crack initiation in notched specimens and crack propagation using a surfing boundary condition. Both plane strain and plane stress are addressed. It is shown that in plane strain, a plastic zone blunts the notch or crack tip which in turn inhibits crack nucleation and propagation. Sufficient load causes the crack to nucleate or unpin, but the crack does so with a finite jump. Therefore the …

Comparison Of The Kinetic Parameters Of Escherichia Coli 0157:H7, Listeria Monocytogenes And Salmonella Typhimurium Derived From The Baranyi And Huang Models In A Chemically Defined Minimal Medium, Jose Isidro Fuentes

LSU Master's Theses

Microbial growth can be characterized by parameters such as lag time, growth rate, and maximum population density at any specific point of time. Mathematical models that predict microbial growth of foodborne pathogens are increasingly used in the food industry as a viable alternative to traditional methods of microbial enumeration. The Baranyi model has been widely used as the primary model of choice by many authors because of its performance and accuracy. The most recently developed Huang model has been less implemented and few comparisons between the Baranyi and Huang models have been made when modeling pathogenic growth. For this research, …

Coarse-Grained Models For Constant Ph Simulations Of Carboxylic Acids, Naeyma N. Islam, Arjun Sharma, Gaurav Gyawali, Revati Kumar, Steven W. Rick

Faculty Publications

© 2019 American Chemical Society. A model for carboxylic acids, in both the protonated and deprotonated states, is developed in which hydrogen interaction sites are not used and all interactions are short-ranged. A method for constant pH simulations, which exploits these features of the model, is developed. The constant pH method samples protonation states by making discrete Monte Carlo steps and is able to efficiently move between states in two steps. The method is applied to the polymer poly(methacrylic acid), a pH-responsive polymer that undergoes structural changes as a function of pH. The model is able to reproduce the structural …

Extendibility Limits The Performance Of Quantum Processors, Eneet Kaur, Siddhartha Das, Mark M. Wilde, Andreas Winter

Faculty Publications

Resource theories in quantum information science are helpful for the study and quantification of the performance of information-processing tasks that involve quantum systems. These resource theories also find applications in other areas of study; e.g., the resource theories of entanglement and coherence have found use and implications in the study of quantum thermodynamics and memory effects in quantum dynamics. In this paper, we introduce the resource theory of unextendibility, which is associated with the inability of extending quantum entanglement in a given quantum state to multiple parties. The free states in this resource theory are the k-extendible states, and the …

Antecedents Of Apparel Subscription Box Choice: Understanding Predictors To Use Apparel Subscription Service, Md Abdullahil Kafi

LSU Doctoral Dissertations

With the rise of online shopping apparel merchandising and retailing has experienced tremendous reformation. In this regard, the online apparel subscription services have become an important trend in a global retailing context. In the U.S. apparel subscription service retailers reported that the market grew by more than 100 percent from 2013 to 2018 and it continues to grow steadily.

The purpose of this study was to investigate the antecedents of online apparel subscription services, and to better understand consumers’ attitudes towards online subscription service items in the context of the extended Unified Theory of Technology Acceptance and Usage (UTAUT2). This …

Effective Use Of Information Systems For Emergency Management: A Representation Theory Perspective, Dario Bonaretti

LSU Doctoral Dissertations

Effective Use Theory (EUT) has emerged as a promising native Information Systems (IS) theory to understand a central phenomenon of interest to the discipline: the effective use of information systems. While EUT is widely accepted in operational control and management control contexts, its validity in chaotic environments has yet to be demonstrated. To contribute to the research program in EUT, scholars called for contextualizing and assessing EUT in chaotic environment, such as emergencies or crises events. This research seeks to apply EUT to understand the effective use of emergency information systems (EMIS). Seeking a grand theory of effective use in …

Exact Solution Of Spherical Mean-Field Plus Special Orbit-Dependent Non-Separable Pairing Model With Multi Non-Degenerate J-Orbits, Feng Pan, Dan Zhou, Yingwen He, Siyu Yang, Yunfeng Zhang, J. P. Draayer

Faculty Publications

Exact solution of spherical mean-field plus a special orbit-dependent non-separable pairing Hamiltonian with multi non-degenerate j-orbits, which is related to two previously known hyperbolic Gaudin models, is explored. It is shown that the Hamiltonian with suitable constraints on the pairing interaction parameters turns to be exactly solvable. The extended one-variable Heine-Stieltjes polynomials associated to the Bethe-Gaudin-Richardson ansatz equations of the solution for any number of pairs k are determined. It is shown that the pair excitation energies can be calculated more easily than those of the separable pairing model studied previously. As examples of the solution, pairing excitation energies with …

Effects Of Adrenergic Or A Combination Of Adrenergic And Opioid Drugs On Assessments Of Insulin Sensitivity In Mares, Lauren Kerrigan

LSU Master's Theses

Excitement is a problem when conducting endocrine tests on fractious horses. Epinephrine (EPI), for example, was shown to obliterate the insulin-induced decrease in blood glucose concentrations. Sedation may be a solution; however, perturbation of results may preclude useful information. The objectives of the four experiments presented herein were 1) to determine the effects of EPI on insulin response to glucose infusion (IR2G), 2) to assess the effects of the α-adrenergic sedative, detomidine (DET), alone or in combination with the opioid agonist, butorphanol (BUT), on IR2G and glucose response to insulin (GR2I), and 3) to assess the effects of BUT alone …

Effects Of Visit Frequency On Swallowing Function During Organ Preservation For Head And Neck Cancer, Mathew Blaine Vansant

LSU Doctoral Dissertations

Chemoradiotherapy is not without risk of injury to the muscles and nerves associated with swallowing function. Current research supports the use of prophylactic behavioral swallowing exercise in the HNC population, however, wide variations in swallowing treatment methodologies exist and no optimal SLP-patient visit frequency has been established. In addition, poor patient adherence to swallowing exercise appears prevalent. The current study explored the impact of speech language pathologist (SLP)-patient contact time, adherence to prophylactic behavioral swallowing exercises, and explored effects of exercise intensity on immediate post-radiation swallowing outcomes. Groups included a high frequency group (5 weekly SLP-patient visits, n = 15), …

Trading Amino Acids At The Aphid–Buchnera Symbiotic Interface, Honglin Feng, Noel Edwards, Catriona M.H. Anderson, Mike Althaus, Rebecca P. Duncan, Yu Ching Hsu, Charles W. Luetje, Daniel R.G. Price, Alex C.C. Wilson, David T. Thwaites

Faculty Publications

Plant sap-feeding insects are widespread, having evolved to occupy diverse environmental niches despite exclusive feeding on an impoverished diet lacking in essential amino acids and vitamins. Success depends exquisitely on their symbiotic relationships with microbial symbionts housed within specialized eukaryotic bacteriocyte cells. Each bacteriocyte is packed with symbionts that are individually surrounded by a host-derived symbiosomal membrane representing the absolute host–symbiont interface. The symbiosomal membrane must be a dynamic and selectively permeable structure to enable bidirectional and differential movement of essential nutrients, metabolites, and biosynthetic intermediates, vital for growth and survival of host and symbiont. However, despite this crucial role, …

Retired Female Gymnasts' Reflections On Body Image And Sense Of Self, Briley Casanova

LSU Master's Theses

Researchers identify the early stages of retirement as a key developmental period when many female athletes struggle with both body image disturbances and changes to identity. Body image disturbances and changes to identity may be especially challenging for former female athletes participating in aesthetic focused sports such as gymnastics, because physical appearance plays an important role in elite performance. This study utilized semi-structured, in-depth interviews with five former NCAA Division I artistic gymnasts to learn about their experiences and perceptions of body image and athletic identity in the early stages of retirement. Three main themes emerged from the interviews: (a) …

Runtime Adaptive Task Inlining On Asynchronous Multitasking Runtime Systems, Bibek Wagle, Mohammad Alaul Haque Monil, Kevin Huck, Allen D. Malony, Adrian Serio, Hartmut Kaiser

Faculty Publications

As the era of high frequency, single core processors have come to a close, the new paradigm of many core processors has come to dominate. In response to these systems, asynchronous multitasking runtime systems have been developed as a promising solution to efficiently utilize these newly available hardware. Asynchronous multitasking runtime systems work by dividing a problem into a large number of fine grained tasks. However, as the number of tasks created increase, the overheads associated with task creation and management cannot be ignored. Task inlining, a method where the parent thread consumes a child thread, enables the runtime system …

Iron-Sulfur Cluster Assembly; In Vivo Analysis Of The Methanogenic Suf System, Evan Dunkle

LSU Master's Theses

Iron-sulfur (Fe-S) clusters are among the most ancient and prevalent of all biological cofactors. Their assembly into associated proteins is a tightly regulated process with many organisms employing multiple cluster assembly pathways. Much is known about Fe-S cluster assembly in aerobic organisms such as Escherichia coli (E. coli) but little is known in regards to cluster assembly in more ancient organisms such as methanogens. Methanogens are members of the domain of Archaea and are defined by their ability to generate methane as a byproduct of their main energy generating pathway. Methanogens also have significantly higher Fe-S cluster content …

The Importance Of Landscape Position Information And Elevation Uncertainty For Barrier Island Habitat Mapping And Modeling, Nicholas Matthew Enwright

LSU Doctoral Dissertations

Barrier islands provide important ecosystem services, including storm protection and erosion control to the mainland, habitat for fish and wildlife, and tourism. As a result, natural resource managers are concerned with monitoring changes to these islands and modeling future states of these environments. Landscape position, such as elevation and distance from shore, influences habitat coverage on barrier islands by regulating exposure to abiotic factors, including waves, tides, and salt spray. Geographers commonly use aerial topographic lidar data for extracting landscape position information. However, researchers rarely consider lidar elevation uncertainty when using automated processes for extracting elevation-dependent habitats from lidar data. …

Probing Stark-Induced Nonlinear Phase Variation With Opto-Optical Modulation, E. R. Simpson, M. Labeye, S. Camp, N. Ibrakovic, S. Bengtsson, A. Olofsson, K. J. Schafer, M. B. Gaarde, J. Mauritsson

Faculty Publications

We extend the recently developed technique of opto-optical modulation (OOM) to probe state-resolved ac-Stark-induced phase variations of a coherently excited ensemble of helium atoms. In a joint experimental and theoretical study, we find that the spatial redirection of the resonant emission from the OOM process is different for the low-lying 1s2p state as compared with the higher-lying Rydberg states, and that this redirection can be controlled through the spatial characteristics of the infrared (IR) probe beam. In particular, we observe that the intensity dependence of the IR-induced Stark phase on the 1s2p emission is nonlinear, and that the phase accumulation …

Giving Four-Year-Old Children A "Voice" Within The Comprehensive Evaluation Of Quality Teaching Practices, Mistie M. Perry

LSU Doctoral Dissertations

Educational research has largely focused on the correlation between governmental entities and classroom pedagogy as policymakers develop more comprehensive evaluation systems that raise the expectations of teacher quality. However, some researchers in the field of early childhood suggest the measurement of teacher quality is largely a “mismatch between informant-based, retroactive methods” (Downer, Booren, Lima, Luckner, & Pianta, 2010, p. 5) as developmentally appropriate measurements of early childhood quality that include the perceptions of the children are few. To examine the potential for researchers to consider the inclusion of children’s perceptions within evaluation systems, this study examines the following area of …

The Effects Of Oil On Blue Crab And Periwinkle Snail Interactions: A Mesocosm Study, Elizabeth M. Robinson, Nancy N. Rabalais

Faculty Publications

We examined the sub-lethal effect of Macondo oil from the Deepwater Horizon oil spill on predator-prey interactions using blue crabs (Callinectes sapidus) and periwinkle snails (Littoraria irrorata). A 2 x 2 factorial mesocosm design determined the effect of oil (no oil vs. oil) and blue crabs (no blue crab predator vs. one blue crab predator) on periwinkle snail climbing and survival. Sixteen mesocosm tanks were used in the experiment, which were replicated three times. Each tank contained water, sand, and Spartina marsh stems. The sixteen tanks were divided between two, temperature-controlled chambers to separate oil treatments (no oil vs. oil). …

Factors Influencing Blue Carbon Accumulation Across A 32‐Year Chronosequence Of Created Coastal Marshes, Katherine M. Abbott, Tracy Elsey‐Quirk, Ronald D. Delaune

Faculty Publications

No abstract provided.

Spatial Variability Of Mangrove Primary Productivity In The Neotropics, Rafaela De Albuquerque Ribeiro, André Scarlate Rovai, Robert R. Twilley, Edward Castañeda-Moya

Faculty Publications

Mangroves are considered one of the most productive ecosystems in the world with significant contributions as carbon sinks in the biosphere. Yet few attempts have been made to assess global patterns in mangrove net primary productivity, except for a few assumptions relating litterfall rates to variation in latitude. We combined geophysical and climatic variables to predict mangrove litterfall rates at continental scale. On a per-area basis, carbon flux in litterfall in the neotropics is estimated at 5 MgC·ha⁻¹·yr⁻¹, between 20% and 50% higher than previous estimates. Annual carbon fixed in mangrove litterfall in the neotropics is …

High-Resolution Mapping Of Biomass And Distribution Of Marsh And Forested Wetlands In Southeastern Coastal Louisiana, Nathan Thomas, Marc Simard, Edward Castañeda-Moya, Kristin Byrd, Lisamarie Windham-Myers, Azure Bevington, Robert R. Twilley

Faculty Publications

No abstract provided.

Remote Impacts Of Typhoons On The Hydrodynamics, Sediment Transport And Bed Stability Of An Intertidal Wetland In The Yangtze Delta, S.L. Yang, J.Q. Fan, B.W. Shi, T.J. Bouma, K.H. Xu, H.F. Yang, S.S. Zhang, Q. Zhu, X.F. Shi

Faculty Publications

No abstract provided.

Use Of Rice Husk Ash (Rha) In Flowable Fill Concrete Mix Material, Zahid Hossain, Kazi Tamzidul Islam

Data

Corresponding data set for Tran-SET Project No. 18CASU03. Abstract of the final report is stated below for reference:

"In the way of finding sustainable development, the flowable fill is a relatively new construction technology. Flowable fill is a self-compacting material, which has been developed in recent years. Flowable fill has been used for different applications such as backfilling walls, sewer trenches, bridge abutments, conduit trenches, pile excavations, and retaining walls. This study examines the potential uses of Rice Husk Ash (RHA) as a sustainable cementitious material (SCM) in the preparation of flowable fill concrete. (RHA is an agricultural by-product of …

Self-Healing Concrete Using Encapsulated Bacterial Spores In A Simulated Hot Subtropical Climate, Marwa Hassan, Jose Milla, Tyson Rupnow, Ahsennur Soysal

Data

Corresponding data set for Tran-SET Project No. 18CLSU02. Abstract of the final report is stated below for reference:

"Bacterial concrete has become one of the most promising self-healing alternatives due to its capability to seal crack widths through microbial induced calcite precipitation (MICP). In this study, two bacterial strains were embedded at varying dosages (by weight of cement) in concrete. Beam specimens were used to identify the maximum crack-sealing efficiency, while cylinder samples were used to determine their effects on the intrinsic mechanical properties, as well as its stiffness recovery over time after inducing damage. The concrete specimens were cured …

Use Of Bagasse Ash As A Concrete Additive For Road Pavement Application, Gabriel Arce, Marwa Hassan, Maria Gutierrez-Wing, Michele Barbato

Data

Corresponding data set for Tran-SET Project No. 18CLSU03. Abstract of the final report is stated below for reference:

"The objective of this study was to evaluate the use of sugarcane bagasse ash (SCBA) as a partial replacement of cement in concrete for road pavement application. The study explored the pozzolanic activity of SCBA produced from three different processing methodologies (i.e., raw SCBA, controlled SCBA and post-processed SCBA). The experimental results revealed that SCBA produced by the controlled burning of sugarcane bagasse fiber (SBF) at 650°C and grinding (C-650), presented the maximum pozzolanic activity. However, this SCBA production process was deemed …

Uhpc Shear Keys In Concrete Bridge Superstructures, Craig Newtson, Brad Weldon, Elsy Flores, Jordan Varbel, William Toledo

Data

Corresponding data set for Tran-SET Project No. 18CNMS01. Abstract of the final report is stated below for reference:

"This research investigated the use of locally produced ultra-high performance concrete (UHPC) as a grouting material to repair deteriorated shear keys. Shear keys are used in adjacent girder superstructures to produce monolithic behavior and load transfer across the structure. Shear key durability is a concern since shear key degradation can jeopardize the integrity of the structure. Transportation agencies have reported that 75% of distress in adjacent girder bridges is due to cracking and de-bonding along shear keys. Previous research has shown that …

Evaluation And Enhancement Of Carbon Sequestration Potential Of Existing Vegetation Along Roadsides, Vikram Kapoor, Jeffrey Hutchinson, Samer Dessouky

Data

Corresponding data set for Tran-SET Project No. 18HSTSA01. Abstract of the final report is stated below for reference:

"The objectives of this study were to evaluate the vegetative composition and carbon sequestration potential of vegetation along a major roadway in Texas. Soil and vegetation were evaluated along IH-35 within Bexar County for composition and carbon content. Three 20 m transects were placed at each site and percent vegetative cover was estimated and above ground plant biomass, and soil was collected from three 0.25 m2 subplots along each transect. Plant and soil samples were analyzed for carbon content. Two non-native grasses, …

Karst Sinkhole Detecting And Mapping Using Airborne Lidar, Su Zhang, Shirley Baros, Susan Bogus

Data

Corresponding data set for Tran-SET Project No. 18GTUNM01. Abstract of the final report is stated below for reference:

"The focus of this study is to detect sinkhole hazards using airborne light detection and ranging (LiDAR) data. The premise is sinkholes, particularly those close to transportation infrastructure assets, could cause substantial damages to infrastructure assets, and therefore, being able to accurately and rapidly detect them is essential. However, it is expensive, time-consuming, labor-intensive, and unsafe to survey sinkholes using conventional ground observation methods. This research project was focused on developing accurate and rapid airborne LiDAR-based sinkhole detection and mapping methods, and …

A Comprehensive Framework For Life-Cycle Cost Assessment Of Reinforced Concrete Bridge Decks, Mohamed Soliman, Samir Ahmed, Ligang Shen

Data

Corresponding data set for Tran-SET Project No. 18STOKS02. Abstract of the final report is stated below for reference:

"Various environmental and mechanical stressors cause deterioration of concrete bridge decks. Normal wear and tear, freeze and thaw cycles, and chloride penetration due to deicing salts can cause aggressive deterioration that usually require frequent interventions during the life-cycle of the bridge. These interventions include deck maintenance and repairs (e.g., application of sealers or overlay placement) as well as bridge deck replacement. The quantification of the life-cycle cost of bridge decks considering maintenance and repair activities represents a significant challenge facing local and …