Digital Commons Network^™

Characteristics And Causal Factors For The Receptive-Expressive Gap In Typically Developed Spanish-English Adult Bilinguals, Rachael Janelle Javaherian

LSU Master's Theses

A receptive-expressive language gap occurs when a standardized receptive score is statistically greater than an expressive score in either a primary or a second language. In bilingual children, gap studies already exist for determining language impairment. In adults, there are few studies; nevertheless, one needs to distinguish between typical language patterns of bilingualism due to non-pathological loss of L1 skills versus problems resulting from accidents, disease, or age. To this end, the present study attempted to expand findings of studies by Gibson et al. (2012 and 2014) that focused on analysis of the gap and possible factors influencing its existence …

Cfd Simulations Of Macroscopic And Microscopic Multiphase Fluid Flow And Droplet Interaction, Aaron Harrington

LSU Master's Theses

Multiphase flow is a complex phenomenon which can be modeled on numerous different length scales, both macroscopically and microscopically. The use of a Euler-Euler model for Computation Fluid Dynamics (CFD) simulations of subcooled boiling phenomena is discussed in detail. The CFD conditions have been set up to mimic previous experimental conditions. A cylindrical vessel with subcooled liquid flow is heated along part of the axial wall of the vessel. A constant heat flux is applied to produce subcooled boiling. We discuss the development of the phase change within the vessel as well as the temperature profile, and validate the results …

Surface Engineering Of Materials For Optical And Biomedical Applications, Syed Mohammad Abid Hasan

LSU Doctoral Dissertations

The mechanisms of various optical and medical applications depend on the characteristics of the surface of the material which is being used to detect the molecule of interest. In this work, we focused on some specific areas of surface engineering that play a vital role to improve the performance of some material characteristics. Firstly, we focused on the wettability of graphene, which is important for surface modification and thermal/fluidic properties. The level of transparency to van der Waals forces, chemical bonds, and electrostatic interactions between atoms and molecules on two sides of graphene single layer is not well understood. Our …

Evaluating Consumers’ Perception Of Gluten-Free/Clean-Label Muffins, Vanesa Chicaiza

LSU Master's Theses

The gluten-free-natural-ingredient (GF/NCL) product demand is globally increasing and driven by the growing prevalence of celiac-diseases. Nevertheless, the quality of GF product is often inferior compared to wheat-flour counterparts due to the removing of gluten, which, compromises the appearance, structure, and nutritional value. The addition of fiber into GF/NCL products has been considered to improve nutritional values while maintaining quality attributes. According to the US-FDA, a product containing ≥2.5 grams of fiber/serving can be claimed as a “good-source-of-fiber.” However, adding dietary fiber to baked products affects their qualities, and hence possibly lowering product acceptability.

The main objective of this research …

Examining The Effectiveness Of “Turn Around Don’T Drown”, Chance D. Bryant

LSU Master's Theses

Extreme heat is the deadliest weather hazard in the U.S. Flooding is the second worst, and flash flooding is the deadliest form of flooding. The nature of these flood deaths contains a human element that deserves greater study. Since 2004, the National Weather Service has attempted to educate the public with its slogan, ``Turn Around Don’t Drown". Vehicle related mortality rates in Texas since 1996 were examined to answer the question of whether ``Turn Around Don’t Drown" has been effective. The slogan has a large footprint on the social media platform Twitter, with most of the Tweets coming from private …

An Evaluation Of The Break Up With Salt Community-Based Hypertension Education Program, Helena L. Salgado

LSU Master's Theses

Introduction: Hypertension is a primary risk factor for heart disease and stroke, and contributes to renal disease, premature death, and disability. More recently, hypertension has also been identified as a risk factor for serious symptoms or as an underlying cause of death from Covid-19. Break up with salt (BUWS) is a 4-session, community-based nutrition education program of the LSU AgCenter, developed in response to the Covid-19 pandemic, to help Louisiana’s adults prevent or mange hypertension. The BUWS curriculum focuses on the DASH diet, healthy food selection and preparation skills, and physical activity and stress management. BUWS was piloted in a …

3-Dimensional Structural Determination Of Epidermal Growth Factor-Like Repeat 27 From Mouse Notch1 Using Nuclear Magnetic Resonance Spectroscopy, Justin Grennell

LSU Doctoral Dissertations

NOTCH1 has been associated with a variety of human ailments, such as cancer and heart disease. NOTCH1 is a transmembrane protein that contains 36 epidermal growth factor-like (EGF) repeats, which facilitate cell signaling by binding proteins on neighboring cells. Each repeat contains about 40 amino acids and has to be folded in a specific manner to function properly. The amino acid sequence, carbohydrate pattern, and calcium-binding sites of EGF-like repeats vary, but the pattern along the 36-repeat chain is conserved. The Abruptex region (EGF24-29) of NOTCH1 is a highly glycosylated (having undergone sugar addition) and flexible region, which gained its …

Role Of Dissipative Effects In The Quantum Gravitational Onset Of Warm Starobinsky Inflation In A Closed Universe, Meysam Motaharfar, Parampreet Singh

Faculty Publications

A problematic feature of low-energy-scale inflationary models, such as Starobinsky inflation, in a spatially closed universe is the occurrence of a recollapse and a big crunch singularity before inflation can even set in. In a recent work, it was shown that this problem can be successfully resolved in loop quantum cosmology for a large class of initial conditions due to a nonsingular cyclic evolution and a hysteresislike phenomenon. However, for certain highly unfavorable initial conditions, the onset of inflation was still difficult to obtain. In this work, we explore the role of dissipative particle production, which is typical in warm …

Asynchronous, Distributed Optical Mutual Exclusion And Applications, Ahmed Bahaael Mansour

LSU Doctoral Dissertations

Silicon photonics have drawn much recent interest in the setting of intra-chip andmodule communication. In this dissertation, we address a fundamental computationalproblem, mutual exclusion, in the setting of optical interconnects. As a main result, wepropose an optical network and an algorithm for it to distribute a token (shared resource)mutually exclusively among a set ofnprocessing elements. Following a request, the tokenis granted in constant amortized time andO(n) worst case time; this assumes constantpropagation time for light within the chip. Additionally, the distribution of tokens is fair,ensuring that no token request is denied more thann−1 times in succession; this is thebest possible. …

Apol1 Renal Risk Variants Are Associated With Obesity And Body Composition In African Ancestry Adults: An Observational Genotype-Phenotype Association Study, Girish N. Nadkarni, Kezhen Fei, Genevieve Galarneau, Yan Gao, James G. Wilson, Richard Cooper, Ebony B. Madden, Joshua C. Denny, Lynne D. Richardson, Martin Pollak, Ruth J.F. Loos, Carol R. Horowitz

Faculty Publications

While increased obesity prevalence among persons of African ancestry (AAs) compared to persons of European ancestry (EAs) is linked to social, environmental and behavioral factors, there are no gene variants that are common and significantly associated with obesity in AA populations. We sought to explore the association between ancestry specific renal risk variants in the apolipoprotein L1 (APOL1) gene with obesity related traits in AAs. We conducted a genotype-phenotype association study from 3 electronic medical record linked cohorts (BioMe Biobank, BioVU, nuGENE); randomized controlled trials (genetic testing to understand and address renal disease disparities) and prospective cohort study (Jackson Heart …

Non-Adiabatic Excited State Molecular Dynamics Using Ehrenfest And Modulated X-Ray Absorption In Titania, Alexander Matthew Meyer

LSU Doctoral Dissertations

This dissertation contains two separate sections aside from an introduction (Chapter 1): theory and methods (Chapter 2), time dependent density functional theory with Ehrenfest for excited state lifetimes in materials (Chapter 3), and simulated field modulated X-ray absorption in titania (Chapter 4).

Excited state lifetime in insulators and semiconductors can be difficult to compute using quantum chemistry due to their dense excited states. Non-radiative decay in these materials requires the use of non-adiabatic effects to dissipate energy through the means of electron-nuclear coupling such as coherent phonon generation. One method of approaching this challenge in these materials is using Ehrenfest …

Brood Abundance And Invertebrate Availability In Crop-Dominated Landscapes In The Prairie Pothole Region, Catrina V. Terry

LSU Master's Theses

The Prairie Pothole Region (PPR) is the most important region for ducks in North America, producing over half the ducks on the continent, and it is a priority landscape for wetland and grassland conservation. Agricultural expansion has changed the PPR, and the majority of grasslands and potholes have been converted into row-crops. The loss of nesting habitat has directly caused nest success to decline. Most of the remaining wetlands are surrounded by row-crops, and are considered lower quality because they receive runoff of sediment and chemicals, which may decrease primary forage for young ducklings as well as inhibit wetland vegetation. …

Time And Tide: Sixteenth-Century Expressions Of Temporality In The Writings Of Richard Hakluyt, Jennifer Hope Tellman

LSU Doctoral Dissertations

Richard Hakluyt the Younger (c. 1553-1616) was the most famous English promoter of overseas expansion of his age and in English history. His most renowned publication, Principal Navigations (1598-1600), a massive three-volume series, detailed English exploration, expansion, and trade history. With a focus on inciting the English to act in order to achieve their Providential Empire, Hakluyt’s works carry in them the expressions of time and temporality permeating the late-1500s. In a period of history where new learning, discoveries, and technologies began to transform life, time was called into question. Concerns about how the perception and acceleration of time and …

Willingness Of Non-Industrial Private Forest Landowners To Obtain A Private Versus Public Consultation, Erika Largacha

LSU Master's Theses

Promoting conservation practices among family forests landowners play a critical role to enhance forest health and ecosystem services. Several certification programs recognize such efforts, but participation among landowners varies based on their characteristics, program requirements, and incentives. One crucial step of certification is to obtain a forest management plan, but acquisition among landowners remains extremely low. Several studies suggest connecting landowners with foresters as the key element towards the adoption of forest management plans. Because foresters are typically employed by public forestry agencies or as private self-employed consultants, landowners' willingness to work with either may differ. As far as we …

Metal Fatigue And Crack Propagation Using Thermodynamic/Thermoelectric Approach, Behnam Hajshirmohammadi

LSU Doctoral Dissertations

The present dissertation concentrates on the fatigue life of metals and fatigue crack growth (FCG). The basic concept of fatigue thermodynamics is used for this purpose. With the application of thermoelectricity, a method is developed on the basis of fracture fatigue entropy (FFE) for the rapid estimation of the fatigue life of components. To this end, thermoelectric signals captured from a specimen during cyclic loading are analyzed, and a procedure is proposed for the calculation of fatigue life based on the thermoelectric signals in the beginning and the steady-state zone of fatigue. Temperature gradient and electric potential gradients in metals …

Investigation Of Arabidopsis Extremophyte Relatives, Schrenkiella Parvula And Eutrema Salsugineum Reveals Different Roads Leading To Salt Stress Tolerance, Kieu-Nga Thi Tran

LSU Doctoral Dissertations

How plants adapt to salt stress has been a central question in plant biology for decades. Yet we have not been able to fully understand the molecular networks and genetic mechanisms underlying this complex trait. Most of the genetic work on salinity stress has focused on understanding salt stress responses in the leading, yet a salt-sensitive model Arabidopsis thaliana. With the recent availability of genomes for wild-relatives of A. thaliana, we can now investigate how naturally salt adapted plants may have evolved modified or novel molecular networks to adapt to salt stress. Therefore, my research utilizes a comparative …

Evaluation Of The Effectiveness Of Aeration During Washing To Dislodge Microorganisms From Cucumbers And Bell Peppers, Julysa Benitez

LSU Master's Theses

Microorganisms may attach firmly to produce matrices and could affect the efficacy of disinfectants. The purpose of this study is to evaluate the effectiveness of aeration to reduce microbial risk during washing and sanitizing of fresh produce. Bell peppers and cucumbers were spot inoculated with Listeria innocua, E. coli O157:H7, and Salmonella; after drying in the biosafety cabinet for 1h, these were washed with water or sanitized with 100 ppm of chlorine for 3 min with or without aeration. Bell pepper and cucumber samples were placed in sterile bags with PBS after treatment. Bell peppers were processed in the stomacher …

African American English-Speaking Children's Judgments Of Grammaticality: Effects Of Clinical Status And Grammatical Structures, Lori Elizabeth Vaughn

LSU Doctoral Dissertations

African American English (AAE)-speaking children’s ability to judge the grammaticality of sentences was evaluated by their clinical status and grammatical structure. The study originated from a need to understand more about the tense and agreement systems of AAE speakers with specific language impairment (SLI) relative to their typically developing (TD) AAE-speaking peers. Tense and agreement forms are typically excluded from the assessment and treatment of children who speak AAE in fear of misinterpreting a dialect difference as a language disorder. As a result, limited information exists about the tense and agreement systems of AAE-speaking children.

The data were archival and …

Genetic Structuring And Community Assembly In Neotropical Birds, Oscar Johnson

LSU Doctoral Dissertations

The factors that influence how species form is of fundamental interest to biology. Under the framework of the speciation cycle, the process begins by population subdivision creating structured populations that then diverge until two new species form. Following speciation, however, continued divergence is necessary for these new species to be able to coexist without adverse interactions, known as the transition to secondary sympatry. At this point the speciation cycle is complete and the process can begin anew. Many of the factors influencing these processes remain poorly understood. Here, I explore the factors that influence speciation and community assembly in Neotropical …

Using Uav Technology Paired With Multispectral Cameras To Assess Crown Rust Epidemics In Oats, Turner A. Graham

LSU Master's Theses

Crown rust, caused by Puccinia cornonata f. sp. avenae, is a common disease of oats (Avena sativa) found virtually everywhere oats are cultivated. This disease has caused yield losses of 10 to 40% worldwide. Early detection is important for effective management. A more recently utilized technology in agriculture is unmanned aerial vehicles (UAVs). UAVs, or drones, equipped with cameras are now being used as a resource to take images of fields to identify pests and other issues that may be occurring. Normalized differentiated vegetative index (NDVI) is a numerical indicator used to determine the vegetative health of …

Efficiency Of Teaching Sight Words In Similar Vs Dissimilar Sets, Jensen Chotto

LSU Master's Theses

Early reading intervention can decrease the likelihood that children who struggle with reading develop long-term reading problems. Due to the prevalence of words that cannot be read phonetically in the English language, sight word instruction is required to supplement phonics instruction. In this study, we compared the effects of creating sets of sight words with the same starting letter (3 words per set, 3 total sets) versus distributing words with the same starting letter across sets when assessing acquisition of the combined set (9 words) in five 4-to-6-year-old children using a combined adapted alternating treatments design and pre-posttest design. All …

Evaluating Substrate Stratification Practices For Enhanced Water Resource Management In Nursery Production, Kristopher S. Criscione

LSU Master's Theses

The nursery and greenhouse industries have continued to increase in production and sales over the past two decades. This increase in horticultural production necessitates a greater demand for finite natural resources, specifically water. Sustainable water resource management will be critical to the success and continual growth of the nursery industry. Strategic irrigation scheduling and innovative substrate management practices can improve nursery resource efficiency. Soilless substrates were originally utilized by the industry to increase substrate air-filled porosity, to ensure adequately drained container systems. Thus, the implementation of these soilless substrates can lead to an inefficient use of water and fertilizer. Substrate …

Impact Of Software Changes On User Experience, Job Michael Champagne

LSU Doctoral Dissertations

Software changes are performed frequently to allow cutting edge features to be delivered to users in a timely manner and to assuage the ever increasing security vulnerabilities found in software. These changes, while necessary, can leave users dissatisfied with software that they use. Security patches can slow down computer performance, and extensive user interface changes can leave users dissatisfied. This research presents a methodology for identifying which software changes have high potential to cause user dissatisfaction. As a part of the methodology, we use natural language processing to analyze the software or system requirements business rule text to determine which …

Fatigue Damage Quantification And Life Estimation With Provision For Microstructure, Arash Pourbagheri Jirandehi

LSU Doctoral Dissertations

This dissertation provides methodologies for the quantification of different forms of fatigue damage by considering the role of microstructure. The laws of thermodynamics in conjunction with Finite Element Method (FEM) are utilized to devise thermodynamically-base frameworks for the estimation of cyclic damage in polycrystalline metals. Accordingly, a microstructure-sensitive platform for fatigue life estimation is introduced. The proposed framework is assessed for 3D printed metallic alloys at room and elevated temperatures. Further, it is used to analyze the fatigue performance difference between additively manufactured Inconel 718 in three print orientations. This research is of fundamental vital interest because it ensures that …

Ontogeny And Resource Use Of Invasive Lionfish, Pterois Volitans, In Shallow Water Habitats Surrounding Summerland Key, Emily Shallow

LSU Master's Theses

The invasive red lionfish, Pterois volitans, has been shown to considerably reduce reef biomass via predation and competition in non-native ranges. Primary maintenance of lionfish is through human removal (e.g., culling), which does not sufficiently control the population due to deep-water spawning, recolonization of recently culled reefs, and ontogenetic migrations to mesophotic waters. Here, I investigated the diets and primary energy pathways during ontogeny in lionfish from the Florida Keys using stomach contents and stable isotope (δ¹³C and δ¹⁵N) analysis to better understand their role in the trophic food web. Additionally, isotopic overlap between lionfish …

An Erp Study Of The Effects Of Iconic And Nonsense Gestures On Memory Formation, Brianna E. Cairney

LSU Master's Theses

Co-speech gesture is an important part of human communication and aids in comprehension, learning, and memory. The addition of iconic gestures to speech has been shown in prior work to enhance memory for the speech. However, it remains unclear as to whether this benefit requires gestures to be meaningful, or, conversely, if any attentionally-engaging gesture will enhance memory. In the current study, we tested two theories to explain the mnemonic benefits of co-speech gesture: Dual Coding Theory, which attributes these benefits to multimodal encoding and enhanced imageability, and Attentional Highlighting Theory, which posits that gestures draw more attention to concurrent …

Tau-Atrophy Variability Reveals Phenotypic Heterogeneity In Alzheimer's Disease, Sandhitsu R. Das, Xueying Lyu, Michael Tran Duong, Long Xie, Lauren Mccollum, Robin De Flores, Michael Dicalogero, David J. Irwin, Bradford C. Dickerson, Ilya M. Nasrallah, Paul A. Yushkevich, David A. Wolk, Michael Weiner, Paul Aisen, Ronald Petersen, Clifford R. Jack, William Jagust, John Q. Trojanowki, Arthur W. Toga, Laurel Beckett, Robert C. Green, Andrew J. Saykin, John Morris, Leslie M. Shaw, Enchi Liu, Tom Montine, Ronald G. Thomas, Michael Donohue, Michael Donohue, Sarah Walter, Devon Gessert, Tamie Sather, Gus Jiminez, Danielle Harvey

Clinical Research Faculty Publications

Objective: Tau neurofibrillary tangles (T) are the primary driver of downstream neurodegeneration (N) and subsequent cognitive impairment in Alzheimer's disease (AD). However, there is substantial variability in the T-N relationship – manifested in higher or lower atrophy than expected for level of tau in a given brain region. The goal of this study was to determine if region-based quantitation of this variability allows for identification of underlying modulatory factors, including polypathology. Methods: Cortical thickness (N) and 18F-Flortaucipir SUVR (T) were computed in 104 gray matter regions from a cohort of cognitively-impaired, amyloid-positive (A+) individuals. Region-specific residuals from a robust linear …

Investigating Black Silicon Surface Geometry Via Parameter Modification And Low Flow Inductively Coupled Plasma Deep Reactive Ion Etching, Noah Mulherin Smith

Honors Capstones

No abstract provided.

How Object Storage Skills Relate To Language Development, Jessica Laurent

Honors Capstones

No abstract provided.

Parent Play Correlates With Infants’ Object Construction Skill, Makayla Barber

Honors Capstones

No abstract provided.