Digital Commons Network^™

Effects Of Riverine Barriers On Avian Evolution In The Amazon Basin, Andre Eugene Moncrieff

LSU Doctoral Dissertations

The high biodiversity found in the Amazon Basin has long captivated the attention of naturalists and evolutionary biologists seeking to explain its origins. Early observations by Alfred Wallace highlighted the role of rivers in delimiting the geographic ranges of many species; furthermore, where rivers narrow towards their headwaters, he noted that some species cross rivers freely. A major goal of this dissertation is to investigate how these and other observations about riverine barriers might inform our understanding of how speciation unfolds in Amazonia. My approach involved generating genomic data with dense geographic sampling for manakins in the genus Lepidothrix, …

Light-Weight Structural Optimization Through Biomimicry, Machine Learning, And Inverse Design, Adithya Challapalli

LSU Doctoral Dissertations

In load-bearing lightweight architectures, cellular materials were frequently utilized. While octahedron, tetrahedron, and octet truss lattice truss were built for lightweight architectures with stretching and flexural dominance, it can be believed that new cells could easily be designed that might perform much better than the present ones in terms of mechanical and architectural characteristics. Machine learning-based structure scouting and design improvisation for better mechanical performance is a growing field of study. Additionally, biomimicry—the science of imitating nature’s elements—offers people a wealth of resources from which to draw motivation as they work to create a better quality of life.

Here, utilizing …

Genetic Characterization Of Resitance To Frogeye Leaf Spot Of Soybean, Gabriel D. Munoz Herrera

LSU Master's Theses

Cercospora sojina is the causal agent of the fungal disease frogeye leaf spot (FLS) in soybeans. Management of this disease consists of foliar application of fungicides and the use of resistant cultivars. However, fungicide resistance has been detected in C. sojina populations and characterization of host resistance genes is relatively limited. To overcome the latter obstacle, we aimed to identify novel resistance genes using quantitative image analysis of the SoyNAM population. Two image analysis workflows using ImageJ and PlantCV were optimized and implemented to increase reproducibility and reduce subjectivity. The quantitative measurements included disease severity, lesion count, and average lesion …

Application Of Distributed Fiber-Optic Sensing For Pressure Predictions And Multiphase Flow Characterization, Gerald Kelechi Ekechukwu

LSU Doctoral Dissertations

In the oil and gas industry, distributed fiber optics sensing (DFOS) has the potential to revolutionize well and reservoir surveillance applications. Using fiber optic sensors is becoming increasingly common because of its chemically passive and non-magnetic interference properties, the possibility of flexible installations that could be behind the casing, on the tubing, or run on wireline, as well as the potential for densely distributed measurements along the entire length of the fiber. The main objectives of my research are to develop and demonstrate novel signal processing and machine learning computational techniques and workflows on DFOS data for a variety of …

Pnp Maxtools: Autonomous Parameter Control In Maxmsp Utilizing Mir Algorithms, Austin Alexander Franklin

LSU Doctoral Dissertations

This research presents a new approach to computer automation through the implementation of novel real-time music information retrieval algorithms developed for this project. It documents the development of the PnP.Maxtools package, a set of open source objects designed within the popular programming environment MaxMSP. The package is a set of pre/post processing filters, objective and subjective timbral descriptors, audio effects, and other objects that are designed to be used together to compose music or improvise without the use of external controllers or hardware. The PnP.Maxtools package objects are designed to be used quickly and easily using a `plug and play' …

Development Of Functional Markers For Resistance To Smut And Identification Of Genes Differentially Expressed In Response To Brown Rust In Sugarcane, Jose David Cortes

LSU Doctoral Dissertations

Smut, caused by Sporisorium scitamineum and brown rust, caused by Puccinia melanocephala, are two of the most important diseases that affect sugarcane production in Louisiana and worldwide. Smut continues to cause losses in the breeding program in Louisiana. Therefore, a QTL analysis was conducted to identify molecular markers associated with resistance in F₁ progeny (162) of a biparental cross between susceptible cultivar L 99-233 and resistant HoCP 96-540. Using 1,574 single-dose SNP markers, a total of 253 linkage groups (LG) were obtained with a genome coverage of 24,580.15 cM. Six QTLs were localized on five LGs. The highest …

Programming The Properties Of Branched Polymers Through Precision Architectures, Michael R. Dearman

LSU Master's Theses

The glass transition of branched polymers is determined by multiple structural parameters that dictate their inter- and intramolecular interactions, and ultimately, their molecular packing in the amorphous phase. Here we examined the impact of side chain length, backbone length, molecular weight composition, and topology on the glass transition behavior of bottlebrush polymers. Through examining precision bottlebrush polymer libraries (PBP, ĐSC = 1.0), we find the infinite molecular weight Tg is reached at a specific brush length after which the effect of the side-chain length dominates. Being a factor more dominant than the backbone, side-chain length affects the Tg of bottlebrush …

Politics & Marriage: The Generational Gap In Marriage Priorities And Political Ambition Among Black Women In Politics, Torri A. Jackson

Honors Theses

No abstract provided.

A Study Of The Effect Of Sympathetic Framing On Attitudes Toward The Homeless, Marshall Mills

Honors Theses

No abstract provided.

Examining The Symbioses Between Bioluminescent Vibrio Species And Ponyfishes In The Indian Ocean And Between Vibrio Species And Crassostrea Virginica In The Gulf Of Mexico, Alexandra Chauvin

Honors Theses

No abstract provided.

Leadership Development And Training In Community-Based Organizations In Myanmar, Anna Rockett

Honors Theses

No abstract provided.

Evaluating The Viscoelastic Properties Of Alligator Skin Gelatin, Alligel, Compared To Mammalian And Fish Gelatins, Sarah E. Jimenez

Honors Theses

No abstract provided.

Hurricane Girls, Kallie Comardelle

Honors Theses

No abstract provided.

Estimation Of Economic Risk From Coastal Natural Hazards In Louisiana, Rubayet Bin Mostafiz

LSU Doctoral Dissertations

Louisiana, U.S.A., is among the most vulnerable areas globally to coastal natural hazards, with risk vulnerability likely increasing. The risks associated with non-tropical-cyclone hazards in Louisiana’s coastal zone have been understudied. This research enhances present and future (i.e., 2050) Louisiana risk assessment using locally-weighted, model-based hazard frequency/intensity and population projections.

Results suggest that property risks associated with extreme cold temperature and tornado are and will remain costlier than those for hail and lightning. Property risks of extreme cold temperature and hail are projected to decrease with the expected warming temperatures, with those of all four of these hazards peaking in …

The Limits Of Financial Equity: The Federal Reserve, The Depression Of 1921, And The End Of Wilsonian Progressivism, Terril Hebert

LSU Master's Theses

The Limits of Financial Equity: The Federal Reserve, the Depression of 1921, and the End of Wilsonian Progressivism is an examination of monetary policy and centralized macroeconomic planning in the American economy during the inflationary spiral of the 1910s that culminated in the Depression of 1921. Put forward for consideration is the successful populist campaign for agricultural credit equity by the burgeoning Federal Reserve System; set against a backdrop of intentional inflation, world and domestic citizens competed against as the price and supply chain distortions perpetuated by the policing of American commerce by the Food Administration, A. Mitchell Palmer’s Department …

The Effects Of Tillage And Cover Crops On Crop Yield And Soil Properties In Wheat Double-Cropping Systems, Peters E. Egbedi

LSU Doctoral Dissertations

This three-year study was conducted on a commerce silt loam soil at the Northeast Research and Experiment Station near St. Joseph, Louisiana to evaluate the following objectives: 1) evaluate crop yield response to tillage, winter, and summer cover crops in wheat double-cropping systems. 2) evaluate the effects of tillage, winter and summer cover crops on soil properties under different cropping systems. 3) quantify the economic benefits of double-cropping, cover cropping and monoculture systems under conventional and no tillage practices. A winter cover crop (WCC) mix (winter wheat (Triticum aestivum and Austrian winter pea (Pisum sativum) and summer …

Studies Of Roseau Cane Dieback In The Lower Mississippi River Delta Based On Remote Sensing Data Including Landsat, Worldview, And Drone, Nan Shang

LSU Doctoral Dissertations

This research focused on the Roseau cane (Phragmites australis) dieback assessment in the lower MRD of Louisiana and introduced a comprehensive and systematic multi-source remote sensing method for assessing wetland and Roseau cane dieback and habitat dynamics analysis from three scale levels from large-scale to small scale.

Large-scale historical vegetation/land change analyses were conducted in the lower MRD based on Landsat in the past two decades (2001 - 2021). A strong increasing trend of vegetation was found since 2005. Around 51 km² ofdieback area was detected which accounts for 11% of the overall vegetation coverage. This research …

Numerical Investigation Of Heat Generation And Accumulation Contributing To Elevated Temperature In Msw Landfills, Alborz Fathinezhad

LSU Doctoral Dissertations

Landfills are complex geostructures which contains organic and inorganic municipal, and in some cases industrial, wastes and are expected to remain operational for long times. Due to the complex nature of physical, chemical, biological, and thermal reactions that carry on within the depths of a landfill, unexpected incidents such as elevated temperatures could become inevitable. While uncommon to happen, elevated temperatures cause health and environmental issues such as odors, rapid settlements, slope instabilities. In addition, elevated temperatures can negatively impact engineered components in composite bottom liners, cover systems, leachate collection, and gas extraction and recovery systems.

Air intrusion into municipal …

Spatiotemporal Transcriptome Diversity And Responses To Salinity Tolerance In The Extremophyte Schrenkiella Parvula, Chathura Wijesinghege

LSU Doctoral Dissertations

Schrenkiella parvula is an extremophyte model related to the most widely studied plant model, Arabidopsis thaliana and Brassica crops in the mustard family (Brassicaceae). It can thrive in highly saline environments where the soil is enriched in Na⁺, K⁺, Li⁺, borates, and chlorides. Understanding how this extremophyte can survive high salinity with genomic adaptations can provide insight into developing stress resilient crops in the future. Gene expression of S. parvula in response to salt has been investigated using shoot and root tissue from mature vegetative-phase plants. However, prior studies have not examined the transcript …

Population Genomic Characterization Of Cercospora Janseana On Rice In The Southern United States, Jacob Searight

LSU Master's Theses

Cercospora janseana is the causative agent of narrow brown leaf spot (NBLS). Effort had been undertaken since the 1940’s to control this disease through resistance breeding in the Southern United States. However, a severe epidemic of NBLS in 2006 inspired renewed focus on managing this disease. One tool for managing this disease has been identified among resistant cultivars, the CRSP-2.1 resistance locus to NBLS. One thing limiting the investment and deployment of CRSP-2.1, and other unknown resistance genes, is the historical observation that resistance to NBLS rapidly breaks-down in the field. Together, the rapid breakdown of resistance to NBLS …

A Machine Learning Approach To Robotic Additive Manufacturing Of Uv-Curable Polymers Using Direct Ink Writing, Luis A. Velazquez

LSU Master's Theses

This thesis presents the design and implementation of a robotic additive manufacturing system that uses ultraviolet (UV)-curable thermoset polymers. Its design considers future applications involving free-standing 3D printing by means of partial UV curing and the fabrication of samples that are reinforced with fillers or fibers to manufacture complex-shape objects.

The proposed setup integrates a custom-built extruder with a UR5e collaborative manipulator. The capabilities of the system were demonstrated using Anycubic resin formulations containing fumed silica (FS) at varying weight fractions from 2.8 to 8 wt%. To fully cure the specimens after fabrication, a UV chamber was used. Then, measurements …

The Applied Use Of Zein Nanoparticles In Agriculture, Colin Bonser

LSU Doctoral Dissertations

Nanotechnology is a multifaceted and a promising strategy in agricultural pest management for the development of insecticides or insecticide carriers. Research has shown that nanoparticles increase stability and efficacy of entrapped chemical pesticides to prevent active ingredient degradation while improving chemical stability and solubility. The following work evaluated nanoparticles synthesized from biopolymers, materials that originate from renewable sources also have an increased biodegradability.
Work was conducted under laboratory, greenhouse, and field conditions to test the biopoloymers as possible insecticide and insecticide carriers. The primary biopolymer evaluated in the following studies was zein, although lignin and chitosan were also evaluated. Overall, …

Experimental Music And Collaboration: Developing Artistry Through Performance Practice, John Lambert

LSU Doctoral Dissertations

This project locates collaboration and collaborative performance as a potential site for artistic growth. This study analyzes six collaborative projects: composed pieces for electric guitar accompanying a staged performance of collaged texts, an audio-visual installation, the preparation of several short pieces to accompany choreographed dances, a 90-minute soundtrack to a performance mixed live, an ongoing improvisational duo, and a live visuals performance to accompany Sunburned Hand of the Man at Duke University. It traces the growth of my artistry while also providing a method for both doing and writing about collaboration. In addition, it offers a model for understanding collaborative …

Paraquat-Resistant Italian Ryegrass (Lolium Multiflorum) Confirmed In Louisiana, Alphonse B. Coco Iii

LSU Master's Theses

Paraquat is the only herbicide labeled for postemergence control of Italian ryegrass in sugarcane. In 2017, sugarcane farmers in Louisiana reported Italian ryegrass control failures with paraquat applications. Seeds were collected from sugarcane fields in White Castle, St. Gabriel, and Bunkie, Louisiana where control was not achieved (reduced susceptibility). Additionally, Italian ryegrass seeds were collected from a sugarcane field in Welcome, LA with a history of paraquat use and with no reported control issues (susceptible population). A dose-response study was conducted at the Louisiana State University Agricultural Center’s Sugar Research Station in February 2021 and was repeated in November 2021. …

Esterase Mediated Insecticide Resistance In The Southern House Mosquito, Culex Quinquefasciatus, Vivek Pokhrel

LSU Doctoral Dissertations

Much is known about the development of insecticide resistance associated with targeted application against insect populations. However, off-target selection by applications of insecticides in agricultural and residential sites also impacts development of insecticide resistance and is understudied. Similarly, the impact of selecting one life stage of mosquitoes on the insecticide susceptibility of different life stages is largely unknown. The first part of this study shows that susceptibility to chlorantraniliprole, which is applied in rice and sugarcane fields in LA, decreased (5.7 to12-fold) in populations of Culex quinquefasciatus collected from near these fields compared to a reference field strain. In addition, …

Sers Platform For Single Fiber Endoscopic Probes, Debsmita Biswas

LSU Doctoral Dissertations

Molecular detection techniques have huge potential in clinical environments. In addition to many other molecular detection techniques, endoscopic Raman spectroscopy has great ability in terms of minimal invasiveness and real-time spectra acquisition. However, Raman Effect is low in sensitivity, limiting the application. Surface-Enhanced Raman Scattering (SERS), addresses this limitation. SERS brings rough nano-metallic surfaces in contact with specimen molecules which enormously enhances Raman signals. This provides Raman spectroscopy with immense capabilities for diverse fields of applications.

Generally, in clinical probe applications, the spectrometer is brought near the target molecules for detection. Typically, optical fibers are used to couple spectrometers to …

Fish And Invertebrate Community And Trophic Structure In The Gulf Of Mexico Coastal Plains Watersheds Across Varying Hydrologic Connectivity., Erin Elizabeth Thayer

LSU Doctoral Dissertations

Subtropical Northern Gulf of Mexico coastal plains watersheds tend to have mild seasonal temperature, low topography, and fine, mostly homogenous substrate sizes; these watersheds may not follow fish and invertebrate community patterns predicted by established lotic paradigms because those paradigms tend to describe communities in either temperate or tropical regions. However, the bases of most generally accepted lotic paradigms involve evaluation of allochthonous and autochthonous contributions to lotic ecosystems via three hydrologic connectivity dimensions including vertical (hyporheic and shallow groundwater), lateral (floodplain), and longitudinal (upstream and downstream). My dissertation goals were to explore these three dimensions within Louisiana coastal plains …

Toward A Safer Transportation System For Senior Road Users, Saba Doulabi

LSU Doctoral Dissertations

Senior pedestrians and drivers (65 years and older) are among the most vulnerable road users. As the population of seniors rise, concerns regarding older adults' traffic safety are growing. The advantages of using autonomous vehicles, innovative vehicle technologies, and active transportation are becoming more widely recognized to improve seniors' mobility and safety. This behooves researchers to further investigate senior road users’ safety challenges and countermeasures. This study contributes to the literature by achieving two main goals. First, to explore contributing factors affecting the safety of older pedestrians and drivers in the current transportation system. Second, to examine seniors’ perceptions, preferences, …

Compilation Optimizations To Enhance Resilience Of Big Data Programs And Quantum Processors, Travis D. Lecompte

LSU Doctoral Dissertations

Modern computers can experience a variety of transient errors due to the surrounding environment, known as soft faults. Although the frequency of these faults is low enough to not be noticeable on personal computers, they become a considerable concern during large-scale distributed computations or systems in more vulnerable environments like satellites. These faults occur as a bit flip of some value in a register, operation, or memory during execution. They surface as either program crashes, hangs, or silent data corruption (SDC), each of which can waste time, money, and resources. Hardware methods, such as shielding or error correcting memory (ECM), …

The Oboe Excerpts: A Preparation Guide For Orchestral Auditions, Jana Zilova

LSU Doctoral Dissertations

This monograph presents an overview of the top ten most requested oboe orchestral excerpts. It provides young aspiring oboists with a better understanding of the pieces, along with different interpretations, to help them prepare for an orchestral audition. The beginning describes how the top ten excerpts were selected and introduces two professional oboe players who contributed to this paper. The middle section provides a background of each piece, pedagogical suggestions, and a list of recordings and books where the oboe excerpts can be found.