Digital Commons Network^™

Bound Preserving Numerical Methods For Infiltration, Arnob Barua

LSU Master's Theses

Simulating the infiltration process in variably saturated media by solving Richards' Equation (RE) remains a computationally challenging task. The degenerate parabolic nature of RE, along with the strongly nonlinear coefficients, makes it very difficult to obtain accurate solutions with conventional numerical methods unless highly refined meshes are used. That is, in the conventional Finite Element Method (FEM), the grid size has to be fine enough to ensure convergence and limit non-physical oscillations, which is computationally expensive. This research aims to develop a second-order accurate FEM discretization with no non-physical oscillations for RE on unstructured meshes which will converge faster than …

Anoctamin 4 Channel Currents Activate Glucose-Inhibited Neurons In The Mouse Ventromedial Hypothalamus During Hypoglycemia, Longlong Tu, Jonathan C. Bean, Yang He, Hailan Liu, Meng Yu, Hesong Liu, Nan Zhang, Na Yin, Junying Han, Nikolas A. Scarcelli, Kristine M. Conde, Mengjie Wang, Yongxiang Li, Bing Feng, Peiyu Gao, Zhao Lin Cai, Makoto Fukuda, Mingshan Xue, Qingchun Tong, Yongjie Yang, Lan Liao, Jianming Xu, Chunmei Wang, Yanlin He, Yong Xu

Division of Basic Science Faculty Publications

Glucose is the basic fuel essential for maintenance of viability and functionality of all cells. However, some neurons —namely, glucose-inhibited (GI) neurons — paradoxically increase their firing activity in low-glucose conditions and decrease that activity in high-glucose conditions. The ionic mechanisms mediating electric responses of GI neurons to glucose fluctuations remain unclear. Here, we showed that currents mediated by the anoctamin 4 (Ano4) channel are only detected in GI neurons in the ventromedial hypothalamic nucleus (VMH) and are functionally required for their activation in response to low glucose. Genetic disruption of the Ano4 gene in VMH neurons reduced blood glucose …

Managing Student Behavior: Occupational And Discrimination-Related Stress As Moderated By Coping Resources, Madeline S. Blocker

LSU Doctoral Dissertations

Student behavior management is a critical component of efficacious teaching and a leading contributor to teachers’ stress. Prior research has shown that teachers experiencing greater levels of workplace stress may utilize more punitive and exclusionary disciplinary techniques. However, these strategies often do not effectively manage student problem behavior and are associated with adverse student outcomes. In contrast, positive behavior management techniques have shown efficacy in managing student behavior while promoting students’ success and wellbeing. This study explored the relationship between teachers’ perceptions of workplace stress (i.e., work-related and discrimination-related) and their use of positive or punitive behavior management techniques. Additionally, …

Analytical Advances In Homeowner Flood Risk Quantification Considering Insurance And Hazard Mitigation, Md Adilur Rahim

LSU Doctoral Dissertations

Accurate economic loss assessment for natural hazards is vital for planning, mitigation, and actuarial purposes. The widespread and costly nature of flood hazards, with the economically disadvantaged disproportionately victimized, makes flood risk assessment and mitigation particularly important. Recent studies have made advancements in assessing flood risk at individual building level. But these methods require solving an integral equation every time the analysis is run, which is computationally intensive. In addition, analyses to date do not consider insurance (i.e., coverage, deductible) information and thus do not estimate the portion of risk that homeowner and insurer bear. Although existing research does consider …

Bridging The Gap Between Detector Characterization And Gravitational Wave Searches In Ligo, Andre Guimaraes

LSU Master's Theses

This thesis, titled ``Bridging the Gap Between Detector Characterization and Gravitational Wave Searches in LIGO'', investigates the complex interplay between detector noise, gravitational wave search algorithms in the operation of the Laser Interferometer Gravitational-Wave Observatory (LIGO) detectors. The non-Gaussian behavior of LIGO detectors' data can lead to numerous issues, ranging from causing the detector to lose operational state to misinterpretations of actual gravitational wave signals.

An introduction to the workings of current interferometric gravitational wave detectors and the characterization of their sources and noise is provided. The focus is then shifted to the GstLAL pipeline, its role, and the effects …

Institutional Rhetoric And Campus Reactions: A Multi-Method Case Study Exploring University Communication And Social Responsibility In A Racial Crisis, Rockia K. Harris

LSU Doctoral Dissertations

This case study explores how an institution in the southeastern conference (SEC) responded to racial reckonings before and after the 2020 murder of George Floyd, how students came to perceive the institution's responses and commitment to diversity and inclusion. To understand this phenomenon beyond apologia and image repair theory, the discourse of renewal theoretical framework and university social responsibility guides this dissertation. This work fills a gap in the literature on crisis communication in response to racism in higher education spaces. Using critical discourse analysis and an open-ended survey, this dissertation further explores the idea of social responsibility of institutions …

Size Effects In Additively Manufactured Inconel-718 Thin Elements And Cellular Structures, Reem Abdelkarim Abo Znemah

LSU Doctoral Dissertations

A current focus in the additive manufacturing (AM) research community is the production of complex shaped metallic parts and cellular structures. Many researchers went on analyzing and simulating these structures without considering the effect of the element thickness and heterogeneous printing parameters on the resulting material behavior. To advance the application of laser powder bed fusion (LPBF), an AM process, in producing Inconel718 (IN718) complex shaped parts and cellular structures, this study aimed to investigate the effect of thin-walled elements thickness on the mechanical characteristics of both the individual elements and overall cellular structure. A multiscale experimental evaluation of the …

First-Principles Simulations Of Attosecond Transient X-Ray Absorption, Min Chen

LSU Doctoral Dissertations

The first part of this dissertation presents calculations of the extinction spec- tra of gold-silver/silver-gold core-shell nanospheres. The goal of this projectsis to get a deeper understanding of surface plasmonic resonance in metal nanospheres with core-shell geometry. Here, we used the finite-difference time-domain (FDTD) method and total-field/scattered-field (TFSF) framework to compute the extinction spectra of nanoparticles to determine the geometry of gold-silver/silver-gold core-shell nanoparticles. This supported experimental work on monitoring the growth dynamics of colloidal gold- silver/silver-gold core-shell nanoparticles using in situ second harmonic generation (SHG) and extinction spectroscopy.

The second and main project involved simulating attosecond transient spectra for …

Exploration Of Efficient Dewatering Methods In Stimulus-Responsive Hydrogels And Their Potential For Desalination, Weiliang Sun

LSU Doctoral Dissertations

Addressing global freshwater scarcity is a pressing challenge, and desalination has emerged as a viable solution to generate high-quality water without compromising natural freshwater ecosystems. In comparison to conventional desalination methods such as thermal distillation and membrane-based processes, hydrogels offer distinct advantages including strong water absorption, water retention, well-defined pore structures, customizable functional groups, and responsive properties to external stimuli. These unique characteristics position hydrogels as promising candidates for water treatment applications. Hydrogel-based desalination involves the utilization of hydrogels to absorb water from saltwater, and then discharge low-concentration solutions to obtain reclaimed water. The fundamental principle underlying the desalination ability …

The Case For Succession Planning In Higher Education: A Study Of Knowledge Transfer Within Louisiana State University, Leila Shaik Villien

LSU Doctoral Dissertations

The primary purpose of this study was to explore the challenges, benefits, and perceptions of succession planning among currently employed administrators at research universities in the southern portion of the United States at the level of assistant department head or higher and the accessible population was defined as currently employed administrators at Louisiana State University at the level of assistant department head or higher. Deans, Associate Deans, Department Heads, Assistant Department Heads, and Department Chairs were invited to participate in an online survey designed by the researcher to assess the attitude toward succession planning and training, along with a variety …

Morphological And Molecular Characterization Of The Olfactory System In The Formosan Subterranean Termite, Paula Castillo

LSU Doctoral Dissertations

The Formosan subterranean termite, Coptotermes formosanus, is a eusocial insect species. Its members live in colonies consisting of reproductive (queen and king) and non-reproductive individuals (workers and soldiers). Olfaction is an essential sense for the social life of many insects. However, in termites, little is known about how olfactory cues are perceived in the peripheral sensory system (antennae) and processed in the central nervous system (brain) to elicit different behavioral responses across castes. In this study, we investigated the olfactory system in all castes (soldiers, workers, and reproductive alates), from the antennal and brain morphology to the antennal gene …

Integrating Behavioral Research Findings With A Liberal Arts Paradigm, Jonathan Peterson

LSU Master's Theses

This paper explores the role of behavioral research in understanding the complexity and relevance of creativity. A brief history of the liberal arts and its current application is followed by a discussion of the importance of variability in generating novel and diverse responses, challenging the notion that creativity is solely a product of innate talent. The effects of reinforcement on variability, and how it relates to a complex relationship between reinforcement and the probability of variable responding leads to a discussion of how the combination of previously trained behaviors can lead to creative problem-solving, emphasizing the role of combinatory behavior …

Sportsman's Paradox: Conservationism And Social Progress In Modern Louisiana, Jacob T. Gautreaux

LSU Doctoral Dissertations

Over the nineteenth and early twentieth centuries, sportsmen increasingly identified Louisiana as a destined paradise due to the abundant flora and fauna. Confirmed in the legendary visits of Theodore Roosevelt in the early 1900s, the conception soon served a dual purpose as individuals like the Tabasco Sauce patriarch, E. A. McIlhenny, coopted the visualization as a lure for business investment into the nascent industrial interests within the coastal region of the state. However, it should be noted that in the 1930s and beyond, cultural conservationists like McIlhenny and Caroline Dormon preserved elements of under-documented cultures throughout the state, although usually …

Neural Mechanisms Of Resiliency And Susceptibility After Repeated Social Defeat, Christy R. Wayne

LSU Doctoral Dissertations

Social defeat is a powerful experience leading to drastic changes in physiology and behavior, many of which are negative. For example, repeated social defeat in vertebrates results in reduced reproductive success, sickness, and behavioral abnormalities that threaten individual survival and species persistence. However, little is known about what neural mechanisms are involved in determining whether an individual is resilient or susceptible to repeated social defeat stress. I used a resident-intruder experiment in the African cichlid fish, Astatotilapia burtoni, to create and investigate the behavior and neural correlates of these two opposing groups. Resilient fish used both searching and freezing behaviors …

“Why We Play The Game”: An Exploration Of Sport Employees’ Conceptualizations Of Meaningful Work, Nathan Baer

LSU Doctoral Dissertations

Modern sport management scholars have looked to pair the fields of positive organizational behavior (POB) and human resource development (HRD) with sport management to enhance the productivity of sport organizations through their employees (see Kim et al., 2019; Kim et al., 2023a; Kim et al., 2023b; Kim et al., 2017; Oja et al., 2015, 2020; Oja et al., 2022; Schuetz et al., 2022; Zvosec et al., 2021). One area of study that has received recent attention amongst sport management scholars is meaningful work (Baer et al., 2021; Oja et al., 2022), an emerging employee well-being metric whose definition is often …

Reef Fish Movement Dynamics And Recruitment To Artificial Habitat, Jade Carver

LSU Master's Theses

Artificial reefs provide critical habitat for fish in areas lacking benthic structure, yet our understanding of how artificial reefs function and develop is limited. Here, changes in reef fish community assemblages were monitored using baited remote underwater video (BRUV) surveys (n=6) before and after a new artificial reef was deployed. Movement of red snapper (Lutjanus campechanus, n=20) and gray snapper (Lutjanus griseus, n=20) between nearby platforms (n=3) and the new artificial reef was examined using acoustic telemetry, and residency was calculated for fish associated with platforms and the artificial reef …

Development And Testing Of A Mapcheck3-Based Patient-Specific Qa Method For Prime Intensity Modulators Used With Bolus Electron Conformal Therapy, James T. Crist

LSU Master's Theses

Purpose: Irregular surfaces in bolus electron conformal therapy (BECT) create target volume dose inhomogeneity, which off-axis intensity modulation (IM) can reduce. This research developed and tested a patient-specific clinical quality assurance (QA) procedure for fabricated Passive Radiotherapy Intensity Modulation for Electrons (PRIME) devices used for IM-BECT delivery.

Methods: To evaluate MapCheck3 (MC3) diode array accuracy, electron dose measurements beneath PRIME devices were compared with scanned measurements in a water phantom. Lateral dose profile comparisons were made for 35 combinations of five beam energies (7-20MeV) and seven PRIME devices - converging and diverging island blocks (pins) having 100-68.8% intensities. To evaluate …

Integrating Cultivar Resistance And Entomopathogens For Pest Management Of Sweetpotato Weevil, Cylas Formicarius Elegantulus (Summers), Schyler M. Lee

LSU Master's Theses

Sweetpotato, Ipomoea batatas (L.) Lam, is the number one vegetable crop in Louisiana, producing 21,178 kg/ha in the year 2021. The sweetpotato weevil, Cylas formicarius elegantulus (Summers), is an economically important pest of sweetpotato. C. formicarius elegantulus females lay eggs into feeding holes on the storage root surface. Larvae then hatch and tunnel through the sweetpotato flesh where they complete their development. This cryptic-natured brentid can cause up to 100% yield loss when left unmanaged. The Louisiana Department of Agriculture and Forestry mandates protocols to limit C. formicarius elegantulus spread (e.g., clean seed, pheromone trapping, and quarantines); however, scheduled chemical …

Characterizing Wind-Wave Flow Physics And Loading Effects On Power Transmission Systems And Offshore Wind Turbines, Tianqi Ma

LSU Doctoral Dissertations

Recent extreme hurricanes caused extensive damage to critical civil infrastructure. Accurate modeling of the extreme complex wind fields and coupled wind-wave fields is essential to quantify the single wind or combined wind-wave loading effects on the structures. This research aims to characterize wind and wind-wave flow physics to quantify the loading effect on power transmission systems and offshore wind turbines.

First, a microscale (∼km) high-fidelity high-resolution computational model is developed to simulate hurricane wind fields with detailed physics. The generated wind field is applied to analyze the structural response of a power transmission system. The proposed hurricane boundary layer (HBL) …

Intensity Modulated Bolus Electron Conformal Therapy (Im-Bect): Methods For Quality Assurance Of Prime Intensity Modulators And Evaluation Of Planned Im-Bect Dose Distributions, Andrew S. Mcguffey

LSU Doctoral Dissertations

Purpose: Intensity-modulated bolus electron conformal therapy (IM-BECT) shapes homogeneous dose distributions to superficial, irregularly-shaped target volumes, avoiding nearby critical structures. This dissertation provides research useful for translating IM-BECT to the radiotherapy clinic by: (1) developing and testing a factory quality assurance (QA) method for fabricated Passive Radiotherapy Intensity Modulator for Electrons (PRIME) devices and (2) verifying an IM-BECT planning and delivery process using end-to-end tests.

Methods: The IM-BECT planning and delivery process determines beam parameters and treatment devices (cutout, bolus, PRIME device) using .decimal’s (Sanford, FL) ElectronRT (eRT) planning system; calculates dose using a pencil-beam redefinition algorithm modified for PRIME …

The Ọkụmkpọ Masquerades Of The Afikpo Society Of Southeastern Nigeria: An Art Form And An Instrument Of Social Control., Chinenye Miriam Emelogu

LSU Master's Theses

Masquerade performances are prevalent in West Africa, but they hold particular importance among the Igbo of Southeastern Nigeria. This thesis explores the cultural significance and artistic expressions of Okunkpo masquerade at Afikpo, a sub-Igbo group in Nigeria. It demonstrates how Okunkpo has served as a mechanism of social control using humorous skits, storytelling and dance up to the 21^st century. Okunkpo is an elaborate and the most attended masquerade performance at Afikpo. It appears only once in a year and is exclusively reserved for male initiates. Its popularity draws audience from far and near. As a community theatre, Okunkpo …

Residential Building Flood Risk Assessment And The Benefits Of Home Elevation, Ayat Al Assi

LSU Doctoral Dissertations

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 is needed to provide valuable information for stakeholder decision-making inside and outside the special flood hazard area (SFHA, which corresponds to the 100-year floodplain). To further inform flood mitigation strategies, quantifying flood risk reduction with home elevation above an initial first-floor height (FFH₀) and the cost effectiveness of federal mitigation assistance for elevation are important steps to enhance awareness of the effect of elevation in reducing flood risk. …

Regulation Of Nucleotide Excision Repair, Wenzhi Gong

LSU Doctoral Dissertations

Nucleotide excision repair (NER), a “cut and patch” mechanism, has two subpathways, namely transcription coupled repair (TCR) and global genome repair (GGR). TCR rapidly removes UV photoproduct (UV PP) in the transcribed strand (TS) of an actively transcribed gene, whereas GGR removes those DNA lesions throughout the genome. This dissertation mainly focused on identifying novel factors that function in NER and investigating the potential molecular mechanisms underlying initial damage recognition and downstream processes in NER. We identified Rpb7, a subunit of RNA polymerase II, represses TCR via its multiple regions. Specifically, the conserved region of Rpb7 that interacts with the …

With Every Name But Yours: A New Orchestration Of Clémence De Grandval's Stabat Mater, David Walters

LSU Doctoral Dissertations

Clémence de Grandval was a late-Romantic composer whose extensive body of work, high profile performances, and numerous accolades should have garnered prominent placement among her contemporaries. Yet her vast collection of orchestral, choral, operatic, and other stage works have been all but forgotten.

Grandval’s Stabat Mater counted among her most popular works. Though the extant score for choir, harmonium (or organ), and piano explicitly references orchestral accompaniment1 , none of the parts or full score are available. Rather than providing a conductor’s guide or chord-by-chord analysis of Grandval’s work, this document breathes new life into this lost masterpiece by orchestrating …

Effects Of Coastal Freshening On Porewater Salinity And Nitrogen Cycling In Brackish Marsh Soils: Implications For Biogeochemical Resilience In Barataria Basin, La, Robert C. Feder

LSU Master's Theses

The Mid-Barataria Sediment Diversion will divert sediments and fresh water from the Mississippi River into mid-Barataria Basin, LA for the purposes of building and sustaining coastal marshes, potentially reducing the estuarine salinity to 0 during operation. Increased freshwater inputs to the area of project influence may reduce porewater salinity and induce ammonium adsorption in brackish marsh soils of the region, potentially impacting the activity of ammonium-producing and denitrifying bacteria. However, brackish soils occur in zones of intermediate salinity and may, therefore, exhibit biogeochemical resilience to episodic changes in surface water salinity. I hypothesized that inundating brackish marsh soils with fresh …

A Systematic Literature Review Of Cleanroom Ventilation And Air Distribution Systems, Arup Bhattacharya, Mohammad Saleh Nikoopayan Tak, Shervin Shoai-Naini, Fred Betz, Ehsan Mousavi

Faculty Publications

Cleanroom ventilation systems are well-established; however, the advantages and limitations of current practices need to be examined and explained further. This study begins by looking over the history of cleanroom ventilation systems that creates the basis for understanding ventilation rate specifications, terminologies employed in ventilation effectiveness, and recognizing scientific studies that correlate ventilation effectiveness with air change rates. This systematic review includes a comprehensive summary that contains a set of historical data and evidence that may be used to specify ventilation requirements in cleanrooms. Scientific articles are classified in terms of laboratory experiments, simulations/numerical analysis, or hybrid. HVAC designers and …

Genome-Wide Association Analysis Identifies Ancestry-Specific Genetic Variation Associated With Acute Response To Metformin And Glipizide In Sugar-Mgh, Josephine H. Li, Laura N. Brenner, Varinderpal Kaur, Katherine Figueroa, Philip Schroeder, Alicia Huerta-Chagoya, Alicia Huerta-Chagoya, Ji Chen, Cassandra N. Spracklen, Gaëlle Marenne, Arushi Varshney, Laura J. Corbin, Jian’An Luan, Sara M. Willems, Ying Wu, Xiaoshuai Zhang, Momoko Horikoshi, Thibaud S. Boutin, Reedik Mägi, Johannes Waage, Ruifang Li-Gao, Kei Hang Katie Chan, Jie Yao, Mila D. Anasanti, Audrey Y. Chu, Annique Claringbould, Jani Heikkinen, Jaeyoung Hong, Jouke Jan Hottenga, Shaofeng Huo, Marika A. Kaakinen, Tin Louie, Winfried März, Hortensia Moreno-Macias

Population and Public Health Science Faculty Publications

Aims/hypothesis: Characterisation of genetic variation that influences the response to glucose-lowering medications is instrumental to precision medicine for treatment of type 2 diabetes. The Study to Understand the Genetics of the Acute Response to Metformin and Glipizide in Humans (SUGAR-MGH) examined the acute response to metformin and glipizide in order to identify new pharmacogenetic associations for the response to common glucose-lowering medications in individuals at risk of type 2 diabetes. Methods: One thousand participants at risk for type 2 diabetes from diverse ancestries underwent sequential glipizide and metformin challenges. A genome-wide association study was performed using the Illumina Multi-Ethnic Genotyping …

Preliminary Validation Of Digital Photography To Assess The Home Food Environment, Daniela Quan, Isaac Michael, Elizabeth Gollub

Faculty Publications

The home food environment (HFE), the availability and accessibility of foods and food products within the home, has a strong influence on healthy eating behaviors. Studies assessing the HFE commonly utilize a home food inventory (HFI) for data collection. However, this approach tends to be burdensome for participants. This study validated a low-burden digital photo method for assessing the home food environment and confirmed that this method is preferred by participants. Study participants completed an HFI, submitted photos of household foods, then identified preference for the HFI or photo reporting method. Researchers completed an HFI based on each participant’s photo …

Investigating The Migratory Behavior Of Soybean Looper, A Major Pest Of Soybean, Through Comparisons With The Corn Pest Fall Armyworm Using Mitochondrial Haplotypes And A Sex-Linked Marker, Rodney N. Nagoshi, Jeffrey A. Davis, Robert L. Meagher, Fred R. Musser, Graham P. Head, Hector Portillo, Henry Teran

Faculty Publications

The Noctuid moth soybean looper (SBL), Chrysodeixis includens (Walker), is an economically important pest of soybean (Glycine max (Linnaeus) Merrill). Because it is not known to survive freezing winters, permanent populations in the United States are believed to be limited to the southern regions of Texas and Florida, yet its geographical range of infestations annually extend to Canada. This indicates annual migrations of thousands of kilometers during the spring and summer growing season. This behavior is like that of the fall armyworm (FAW), Spodoptera frugiperda (J.E. Smith), also a Noctuid that is a major global pest of corn. SBL and …

An Extended Investigation Of Unexpected Helicoverpa Zea (Boddie) Survival And Ear Injury On A Transgenic Maize Hybrid Expressing Cry1a/Cry2a/Vip3a Toxins, Fangneng Huang, Ying Niu, Tiago Silva, Sebe Brown, Tyler Towles, Dawson Kerns, Juan Luis Jurat-Fuentes, Graham P. Head, Matthew Carroll, Wade Walker, Shucong Lin

Faculty Publications

The wide occurrence of resistance to Cry1A and Cry2A insecticidal toxins from Bacillus thuringiensis (Bt) in the corn earworm/bollworm Helicoverpa zea (Boddie) leaves the Vip3A toxin produced during the vegetative stage of Bt as the only fully active toxin expressed in transgenic crops to control H. zea in the U.S.A. During 2021, the first unexpected survival of H. zea and injury (UXI) on a maize hybrid expressing Cry1A.105, Cry2Ab2, and Vip3Aa in Louisiana, U.S.A. were observed in two sentinel plots used for resistance monitoring. A follow-up intensive investigation was conducted with two H. zea populations established from larvae collected from …