Digital Commons Network^™

Demystifying Longitudinal Data Analyses Using Structural Equation Models In School Psychology, Garret J. Hall, Kelly N. Clark

Faculty Publications

Structural equation models (SEM) are a method of latent variable analysis that offer a high degree of flexibility in terms of modeling methods for applied research questions. Recent advancements associated with longitudinal SEM have unlocked innovative ways to decompose variance and to estimate mean trends over time (e.g., Allison et al., 2017; Berry & Willoughby, 2017; Hamaker et al., 2015; McArdle & Nesselroade, 2014). However, these longitudinal methods are not necessarily readily accessible to scholars seeking to advance theory and practice in school psychology. Importantly, not all longitudinal data are the same and not all longitudinal SEMs are the same; …

A Kronecker Limit Formula For Indefinite Zeta Functions, Gene S. Kopp

Faculty Publications

We prove an analogue of Kronecker’s second limit formula for a continuous family of “indefinite zeta functions”. Indefinite zeta functions were introduced in the author’s previous paper as Mellin transforms of indefinite theta functions, as defined by Zwegers. Our formula is valid in dimension g= 2 at s= 1 or s= 0 . For a choice of parameters obeying a certain symmetry, an indefinite zeta function is a differenced ray class zeta function of a real quadratic field, and its special value at s= 0 was conjectured by Stark to be a logarithm of an algebraic unit. Our formula also …

Wedge Domains In Compactly Causal Symmetric Spaces, Karl Hermann Neeb, Gestur Ólafsson

Faculty Publications

Motivated by constructions in Algebraic Quantum Field Theory we introduce wedge domains in compactly causal symmetric spaces M = G/H, which includes in particular anti-de Sitter space in all dimensions and its coverings. Our wedge domains generalize Rindler wedges in Minkowski space. The key geometric structure we use is the modular flow on M defined by an Euler element in the Lie algebra of G. Our main geometric result asserts that three seemingly different characterizations of these domains coincide: the positivity domain of the modular vector field, the domain specified by a KMS-like analytic extension condition for the modular flow, …

Effects Of Yogurt With Carao (Cassia Grandis) On Intestinal Barrier Dysfunction, Α-Glycosidase Activity, Lipase Activity, Hypoglycemic Effect, And Antioxidant Activity, Ricardo S. Aleman, Jhunior Marcia, Ryan Page, Shirin Kazemzadeh Pournaki, Daniel Martín-Vertedor, Víctor Manrique-Fernández, Ismael Montero-Fernández, Kayanush Aryana

Faculty Publications

Cell inflammation disrupts intestinal barrier functions and may cause disorders related to a leaky gut, possibly leading to diabetes. The objective of this study was to determine if carao (Cassia grandis) incorporated into yogurt enhances in vitro intestinal barrier function. To achieve this goal, Caco-2 cells were used as a model of intestinal barrier permeability. Caco-2 cells were treated with cytokines (interleukin-1β, tumor necrosis factor-α, interferon-γ, and lipopolysaccharide (LPS)) and yogurt with carao yogurt (CY) at different doses (1.3 g/L, 2.65 g/L, and 5.3 g/L). Real-time quantitative polymerase chain and immunofluorescence microscopy were applied to evaluate the expression and localization …

Thermoset Polymer Composites With Gradient Natural And Synthetic Fiber Reinforcement: Self-Healing, Shape-Memory, And Fiber Recyclability, Sakil Mahmud, John Konlan, Jenny Deicaza, Rachel Anna Schmidt, Guoqiang Li

Faculty Publications

Natural fibers have high potential as renewable reinforcement for polymers; however, their lower load-carrying capacity compared to synthetic fibers significantly limits the wide application in fiber-reinforced polymer composites. In laminated composite beams under bending load, the normal stress is the highest on the top and bottom layers but is zero at the mid-plane, with almost a linear normal strain distribution. Although the shear stress is the highest at the mid-plane, it may not be a major concern as most polymers can survive the high shear stress. Using this concept, we have designed a hybrid fiber reinforcement in a gradient manner: …

On The Characteristics Of Fatigue Fracture With Rapid Frequency Change, Mohammad A. Amooie, K. P. Lijesh, Ali Mahmoudi, Elaheh Azizian-Farsani, Michael M. Khonsari

Faculty Publications

The effect of sudden variations in working modes and fatigue behavior of CS 1018 is studied. A general model based on the framework of the fracture fatigue entropy (FFE) concept is developed to capture such changes. Fully reversed bending tests are performed on flat dog bone specimens with a series of variable frequency tests without turning the machine off to simulate fluctuating working conditions. The results are then post-processed and analyzed to assess how fatigue life changes when a component is subjected to sudden changes in multiple frequencies. It is demonstrated that regardless of the frequency changes, FFE remains constant …

Ecology Of Viruses In Marine And Coastal Oxygen-Depleted Waters, Sophie Jurgensen

LSU Doctoral Dissertations

Deoxygenation of marine and coastal waters, both caused and exacerbated by a suite of abiotic and biotic factors, has been documented for more than sixty years. The incidence and severity of low-oxygen areas is predicted to expand globally in the coming decades. Despite their colloquial moniker “dead zones,” low-oxygen areas contain thriving and diverse microorganisms that have significant impacts on global biogeochemical cycles including contributing to positive feedback loops that further expand low-oxygen areas. While the diversity and activity of these microorganisms is beginning to be elucidated, the ecology of their viruses is particularly understudied. In this dissertation, I present …

Synthesis Of An Acinetobacter Baumannii Lipooligosaccharide Subunit, James M. Armstrong Ii

LSU Doctoral Dissertations

Acinetobacter baumannii is a Gram-negative, multi drug-resistant bacterium that was placed on the World Health Organization’s watchlist of drug-resistant bacteria. A. baumannii is an ESKAPE pathogen, one of six increasingly antimicrobial-resistant bacteria that are responsible for nosocomial infections. Alternative therapies, such as vaccines, are required to decrease the world’s reliance on antimicrobial agents. Specifically, glycoconjugate vaccines such as those used against Haemophilus influenzae B, Streptococcus pneumoniae, and Neisseria meningitidis are used globally and are highly effective. These vaccines consist of an antigenic bacterial glycan bound to a carrier protein. The glycan is usually a capsular polysaccharide (CPS), however, the notion …

Computer-Aided Drug Design Of Bakuchiol-Inspired Lxrα Modulators Against Acute Lymphoblastic Leukemia, Dillon P. Cao

LSU Master's Theses

Acute lymphoblastic leukemia (ALL) is the most common type of cancer in children, accounting for approximately 25% of pediatric malignancies. Although glucocorticoids are commonly used to treat ALL, prolonged use can lead to steroid resistance, rendering the drug regimen ineffective. Therefore, alternative treatment avenues are needed for high- risk pediatric patients that do not respond well to traditional regimens.

Liver X Receptor α (LXRα) is presented as a potential alternative drug target for pediatric patients that exhibit suboptimal response to glucocorticoids. Limitations of the current LXRα modulators such as indiscriminate isoform selectivity between LXRα and LXRβ and consequent adverse effects …

Experiments And Data Analysis For Modulated Phase Gratings In X-Rays, Sydney B. Carr

LSU Master's Theses

Purpose: Modulated Phase Grating (MPG) interferometry has been shown in theory and simulations to produce observable fringes on a clinical detector without requiring fluence absorbing analyzer. In this work, we will experimentally show that the MPG X-ray system produces observable fringes and multi-modal X-ray images.

Motivation:Nearly 1 in 8 women in the US will develop invasive breast cancer in their lifetime, accounting for approximately 40,000 deaths each year [1-2]. In order to pursue the best treatment option available, cancer itself must be adequately imaged and staged, based on size and level of metastasis, on the order of Stage I-IV. …

Remote Sensing And Artificial Intelligence-Based Modeling And Prediction Of Harmful Algal Blooms In Lake Pontchartrain, Ian Smith

LSU Master's Theses

Harmful Algal Blooms (HABs) and particularly toxic cyanobacterial harmful algal blooms (CyanoHABs) have become a growing threat to the environment, economy, communities, and human and animal health. This is particularly true for Lake Pontchartrain. Forecasting the occurrence of cyanobacterial HABs in Lake Pontchartrain is a process that currently does not exist, as nowcasting by the NCCOS Algal Bloom Monitoring System or the similar system implemented by the U.S. EPA is currently the only method to monitor HAB production in the Lake. This thesis made this process possible by identifying antecedent environmental conditions controlling CyanoHABs, describing the conditions using NASA satellite …

Reconstruction Of Volumetric Modulated Arc Therapy-Computed Tomography, Chia-Lung Chien

LSU Doctoral Dissertations

Purpose: Volumetric modulated arc therapy-computed tomography (VMAT-CT) was proposed in 2010 as the CBCT reconstruction technique using portal images collected during VMAT. Yet, its clinical applications were impeded by the poor image quality due to motion blurs from fast movements of multi-leaf collimator (MLC) and projection data deficiency due to truncations from MLC. The goal of this study is to develop systematic preprocessing methods, and a novel iterative reconstruction algorithm to generate quality VMAT-CT and lower the number of failure cases of VMAT-CT reconstruction.

Methods: Systematic image preprocessing methods, including Online region-based active contouring (ORACM), MLC motion modeling and outlier …

Learning–Assisted Constraint Filtering To Enhance Power System Optimization Performance, Fouad Hasan

LSU Doctoral Dissertations

Machine learning (ML) is a powerful tool that provides meaningful insights for operators to make fast and efficient decisions by analyzing data from power systems. ML techniques have great potential to assist in solving optimization problems within a shorter time frame and with less computational burden. AC optimal power flow (ACOPF), dynamic economic dispatch (D-ED), and security-constrained unit commitment (SCUC) are the three energy management optimization functions studied in this dissertation. ACOPF is solved every 5~15 minutes. Because of the nonconvex and complex nature of ACOPF, solving this problem for large systems is computationally expensive and time-consuming. Classification and regression …

Maximum Likelihood Estimation Of Glandular Fraction For Mammography, Bryce Smith

LSU Master's Theses

Breast tissue is a mixture of adipose and fibro glandular tissue with a glandular fraction on average of 20%-30%. Previous studies have confirmed that there is a risk of undetected breast cancer related to the amount of glandular tissue present in the breast. Since a higher glandular fraction can lead to an increased cancer risk, it is important for radiologists to know quantitative glandular fraction when diagnosing a patient. Another increasingly popular protocol for mammography is to eliminate the anti-scatter grid and use software algorithms to reduce scatter. This work focuses on using a maximum likelihood algorithm to estimate the …

Behavior Of Gas Influx In Riser And Considerations For Riser Gas Handling, Mahendra Kumar Kunju

LSU Doctoral Dissertations

Conventional methods of managing Gas-in-Riser events are not optimal when the riser is isolated from the formation by a closed subsea blowout preventer (BOP) on rigs equipped with Mud-GasSeparator (MGS), Managed Pressure Drilling (MPD), or Riser Gas Handling (RGH) equipment. As the use of adaptive drilling processes like MPD facilitates drilling of otherwise non-drillable wells with faster corrective action, the drilling industry should include the effect of gas solubility, dispersion, bubble suspension, fluid compressibility as well as riser ballooning to avoid overestimation of riser pressure and produce more efficient well control methods. The IADC Deepwater Well Control Guideline recommends always …

An Evaluation Of Procedures To Increase Medical Device Compliance, Sarah Christian Holmes

LSU Doctoral Dissertations

Behavioral interventions have been implemented to increase compliance with medical devices across patient populations and target devices. Intervention to increase medical device compliance (MDC) can involve a variety of components, including different reinforcement, graduated exposure, extinction, and punishment with varying degrees of acceptability and feasibility. In the current study, we compared the effects of noncontingent (NCR) versus synchronous reinforcement schedules on the duration of MDC and latency to device removal with KN95 face masks with 2 patients with Autism Spectrum Disorder. Following an initial baseline phase demonstrating that both participants engaged in compliance for less than 5 min, we used …

Measurement Of The Β-Decay Properties Of A=105 Isotopes Using The Modular Total Absorption Spectrometer And The Development Of The Beta Spectrum Module, Thomas J. Ruland

LSU Doctoral Dissertations

Nuclear reactors produce an extremely diverse population of beta-decaying isotopes. Accurate and precise knowledge of the beta-decay properties of these isotopes is vital to safe reactor operations as well as informing next-generation reactor design. These beta-decay properties not only impact the design and operation of nuclear reactors, but they influence the expected antineutrino flux and spectrum measured from nuclear reactors. Historical measurements of many of these isotopes are subject to a systematic bias referred to as the Pandemonium Effect, because the low-efficiency, high-precision detectors used to perform the measurements results in misinterpreting weak gamma cascades from high- energy levels as …

Exploring Machine Learning In Deep Foundation And Soil Classification Application, Mohammad Moontakim Shoaib

LSU Master's Theses

The applicability of several Machine Learning (ML) models was explored in this research to predict the ultimate capacity and load-settlement behavior of axially loaded single-driven piles from Cone Penetration Test (CPT) data. Additionally, a common CPT-based soil behavior type (SBT) classification system was reproduced using those ML models. Eighty static pile load tests and corresponding CPT data close to those pile locations were collected from 34 sites in Louisiana for the deep foundation application. On the other hand, 70 CPT soundings were taken in 14 different parishes across Louisiana for the soil classification application. Specifically, tree-based ML models such as …

Synthesis And Characterization Of Porphyrin-Encapsulated Nanoparticles: Investigations With Scanning Probe Microscopy, Olajumoke Helen Olubowale

LSU Doctoral Dissertations

Scanning probe microscopy (SPM) encompasses a family of surface measurements that use a sharp probe to “feel” a surface. The tip is scanned point-by-point to build a map of the sample topography, which can be correlated with local measurements of surface properties. This dissertation outlines the history of SPM and describes techniques, operational modes, and applications. A review of force volume mapping (FVM), a 3D characterization mode of SPM used to map material properties detailed. Force volume mapping can be achieved by measuring multiple force measurements point-by-point in a grid pattern. Local properties such as chemical forces, dielectric properties, nanomechanical …

Modelling Illiquid Stocks Using Quantum Stochastic Calculus: Asymptotic Methods, Will Hicks

Journal of Stochastic Analysis

No abstract provided.

Atmospheric Impacts From The 2010 Deepwater Horizon Oil Spill, Charles Philip Johnson

LSU Master's Theses

Although the ecological devastations induced by an oil spill are well studied, the hydrometeorological impacts from a long-term slick have gone unnoticed. The ocean-surface alterations stemming from the lasting oil footprint increase solar radiation absorption which in turn alters the surface pressure and moisture gradients and wind speeds thereby influencing precipitation surrounding the oil spill. Revealing the potential impacts from these could better aid in the safety of crews cleaning spills and provide a better understanding of how humans alter the landscape. This thesis examines the changes in local hydrometeorology brought on by the 2010 summer Deepwater Horizon (DWH) oil …

Errata: Continuous Lattices And Domains, Jimmie D. Lawson

Seminar on Continuity in Semilattices

No abstract provided.

Uniqueness Of Relaxation Times Determined By Dielectric Spectroscopy, Mengchun Wu, Karin J. Bichler, Bruno Jakobi, Gerald J. Schneider

Faculty Publications

Dielectric spectroscopy is extremely powerful to study molecular dynamics, because of the very broad frequency range. Often multiple processes superimpose resulting in spectra that expand over several orders of magnitude, with some of the contributions partially hidden. For illustration, we selected two examples, (i) normal mode of high molar mass polymers partially hidden by conductivity and polarization and (ii) contour length fluctuations partially hidden by reptation using the well-studied polyisoprene melts as example. The intuitive approach to describe experimental spectra and to extract relaxation times is the addition of two or more model functions. Here, we use the empirical Havriliak-Negami …

Sucrose Demand And Essential Value In Mice With Early-Life Exposure To Risperidone, Megan Federoff

LSU Master's Theses

Second-generation antipsychotics (SGAs), such as risperidone, are widely prescribed to children, but the long-term effects of SGA treatment are not well understood. This study investigated the impact of early-life risperidone treatment on sucrose demand in mice in adulthood. Mice were administered risperidone or vehicle from postnatal day (PND) 33 to 60 and trained in adulthood (>PND 120) to nose poke for a sucrose solution reinforcer. The fixed ratio (FR) value (the number of responses required to produce sucrose delivery; the “price” of sucrose) was varied from 1 to 45, and the resulting consumption versus FR value data were analyzed …

An Investigation On The Resilience Of Long Short-Term Memory Deep Neural Networks, Christopher Vasquez

LSU Master's Theses

In a world of continuously advancing technology, the reliance on these technologies continues to increase. Recently, transformer networks [22] have been implemented through various projects such as ChatGPT. These networks are extremely computationally demanding and require cutting-edge hardware to explore. However, with the growing increase and popularity of these neural networks, a question of reliability and resilience comes about, especially as the dependency and research on these networks grow. Given the computational demand of transformer networks, we investigate the resilience of the weights and biases of the predecessor of these networks, i.e. the Long Short-Term (LSTM) neural network, through four …

Mathematics Library News, Aaron Lercher

Faculty Publications

Mathematics Library News is an LSU Libraries newsletter for members of the Mathematics and Experimental Statistics Departments, published roughly once each semester.

Networks In Motion: The Alliances Of Information Communication Technologies And Mobility Technologies During The 1918 Influenza Pandemic, Miles C. Coleman, Will Mari

Faculty Publications

In this article, we turn back to the 1918 influenza pandemic to throw light on the alliances of information communication technologies and technologies of mobility (such as the car) during the pandemic. We examine newspaper articles, technical publications, and other historical texts to demonstrate that, despite the fact that mobile technologies—such as cellular phones—did not exist during the 1918 pandemic, the telephone and mobility technology nonetheless formed alliances as networks in motion, or social moments in which risk and reward are calculated not simply by the ability to move, but rather the ability to move, while remaining connected, revealing insight …

Gifts And Commodities: A Dialectical Thought Experiment For Sublation, Ruirui Zhang, Joseph D’Andrea, Chunmin Lang

Faculty Publications

The core motivation for this study is the realization that the Sustainable Development Goals (SDGs) encounter temporary obstacles, conflicts, or inconsistencies that impede progress and generalization. According to the authors, sustainable development across social, environmental, and economic dimensions is unlikely to occur without redefining the meaning and recalibrating the metrics used to measure commodities. These meanings and metrics must align with values such as general reciprocity, morality, and the common good, going beyond mere calculations of means and ends and personal preferences. The research has three primary objectives: first, to compare and reassess the meanings and responsibilities assigned to “items” …

Nearly-Lossless-To-Lossy Medical Image Compression By The Optimized Jpegxt And Jpeg Algorithms Through The Anatomical Regions Of Interest, Zhongqiang Li, Alexandra Ramos, Zheng Li, Michelle L. Osborn, Waleed Zaid, Xin Li, Yanping Li, Jian Xu

Faculty Publications

Currently, plenty of image data is generated that complicate storage and image transmission. Great efforts have been attempted on how to increase compression ratio (CR) without loss of critical diagnostic information. In this study, we designed two optimized JPEGXT (JPEGXT_OPT) and JPEG (JPEG_OPT) approaches by amplifying discrete cosine transform coefficients and using the entire anatomical region as ROI (region of interest). We found that ROI percentages have a great impact CR: smaller ROI percentages (10–30 %) could obtain a larger CR. Under the near-lossless compression, JPEGXT_OPT could have CRs up to 4.0 under small ROI percentages (10–30 %), while only …

On The Application Of Probabilistic Decline Curve Analysis To Unconventional Reservoirs, U. C. Egbe, O. O. Awoleke, O. M. Olorode, S. D. Goddard

Faculty Publications

Several authors have worked on combining decline curve analysis (DCA) models and stochastic algorithms for probabilistic DCAs. However, there are no publications on the application of these probabilistic decline curve models to all the major shale basins in the United States. Also, several empirical and analytical decline curve models have been developed to fit historical production data better; there is no systematic investigation of the relevance of the efforts on new model development compared with the efforts to quantify the uncertainty associated with the “noise” in the historical data. This work compares the uncertainty associated with determining the best-fit model …