Digital Commons Network^™

Element Transport In A River-Lake Continuum Across Forest-Dominated Landscapes: A Case Study In Central Louisiana, Zhen Xu

LSU Doctoral Dissertations

Studying the biogeochemical connectivity between rivers and lakes can help us understand their ecological and environmental impacts within a drainage basin, which is especially true for forest watersheds that play a vital role in provisioning freshwater services to ecosystems and downstream communities. This dissertation research consists of three interconnected studies with the overarching goal of discerning the connectivity of elements in a river-lake continuum across forest-dominated landscapes. These studies utilized water samples and in situ measurements collected from the Little River-Catahoula Lake continuum in the subtropical Louisiana, USA at monthly intervals during 2015-2016 and 1978-2008 historical water quality, hydrological and …

Acoustic Characteristics Of Word-Final American English Liquids Produced By L2 Adult Speakers, Judith A. Espinal

LSU Master's Theses

In this study, the acoustic differences between native English speakers’ (L1) and native-Korean speakers’ (L2) production of American English liquids /ɹ/, /l/ and /ɹl/ were examined among 14 Korean speakers and 13 English speakers. Temporal measures included (1) relative timing of maximum constriction and (2) duration of vocalic nuclei. Spectral measures included (1) Euclidean distance between /ɹ/ and /l/ and (2) frequency difference between F2 and F3. The results indicated a significant interaction between speaker group and phonetic stimuli. That is, L2 speakers produced a similar degree of constriction across semivowels, whereas L1 speakers produced varying degrees of F2-F3 constrictions …

Automated Extraction Of Network Activity From Memory Resident Code, Austin Nicholas Sellers

LSU Master's Theses

Advancements in malware development, including the use of file-less and memory-only payloads, have led to a significant interest in the use of volatile memory analysis by digital forensics practitioners. Memory analysis can uncover a wealth of information not available via traditional analysis, such as the discovery of injected code, hooked APIs, and more. Unfortunately, the process of analyzing such malicious code is largely left to analysts who must manually reverse engineer the code to discover its intent. This task is not only slow and error-prone, but is also generally left only to senior-level analysts to perform, given that significant reverse …

The Fantastic Bildwelten Of Wolfgang Harms, Tanya A. Kramer

LSU Master's Theses

Wolfgang Harms is an artist from Nuremberg, Germany, who has not been studied at length in the recent past. This thesis explains why the artist is deserving of study. The first chapter is a biographical introduction to the artist and his early works. The following chapters discuss the importance of Nuremberg and mural painting to Harms. The final chapter will analyze the artist’s place in the historical context of Fantastic Realism and the history of art in general. Overall, the purpose of the thesis is to show how Wolfgang Harms is a unique independent-minded artist, who is deserving of more …

"User Experience With A New Public Interface For An Integrated Library System", Kelly D. Blessinger, David Comeaux

Faculty Publications

The purpose of this study was to understand the viewpoints and attitudes of researchers at Louisiana State University toward the new public search interface from SirsiDynix, Enterprise. Fifteen university constituents participated in user studies to provide feedback while completing common research tasks. Particularly of interest to the librarian observers were identifying and characterizing where problems were expressed by the participants as they utilized the new interface. This study was approached within the framework of the cognitive load theory and user experience (UX). Problems that were discovered are discussed along with remedies, in addition to areas for further study.

Tidal And Nonequilibrium Casimir Effects In Free Fall, Justin H. Wilson, Francesco Sorge, Stephen A. Fulling

Faculty Publications

In this work, we consider a Casimir apparatus that is put into free fall (e.g., falling into a black hole). Working in 1+1D, we find that two main effects occur: First, the Casimir energy density experiences a tidal effect where negative energy is pushed toward the plates and the resulting force experienced by the plates is increased. Second, the process of falling is inherently nonequilibrium and we treat it as such, demonstrating that the Casimir energy density moves back and forth between the plates after being "dropped," with the force modulating in synchrony. In this way, the Casimir energy behaves …

Reliable Solar Irradiance Prediction Using Ensemble Learning-Based Models: A Comparative Study, Junho Lee, Wu Wang, Fouzi Harrou, Ying Sun

Faculty Publications

Accurately predicting solar irradiance is important in designing and efficiently managing photovoltaic systems. This paper aims to provide a reliable short-term prediction of solar irradiance based on various meteorological factors using ensemble learning-based models that take into account the time-dependent nature of the solar irradiance data. The use of ensemble learning models is motivated by their desirable characteristics in combining several weak regressors to achieve an improved prediction quality relative to conventional single learners. Furthermore, they reduce the overall prediction error and have the ability to combine different models. In this paper, we first investigate the prediction performance of the …

Model Development To Assess Groundwater Flooding And Levee Underseepage In New Orleans, Louisiana, Shuo Yang

LSU Master's Theses

Flooding is a major threat to New Orleans due to its geographic location and geologic condition. However, potential groundwater flooding is seldom studied and poorly understood even though groundwater level is expected high in the city. High groundwater level might result in groundwater flooding in low-lying areas. High uplift pore water pressures may cause strong underseepage and risk levee safety. The objective of this study is to assess the impacts of hydrogeology on groundwater flooding and evaluate potential underseepage-induced hazards along levees in New Orleans. In this study, a groundwater flow model development which involves stratigraphy modeling, groundwater flow model …

Symphony No.2 And The Text Setting Of Henry Purcell's Dido And Aeneas, Sungho Kim

LSU Doctoral Dissertations

This work is conceived as a unit that has two parts. Part one is an original composition, Symphony No. 2. This piece is scored for symphony orchestra and it is a sequel of the composer’s master thesis, a symphonic poem titled Moonlight Sprite, which describes the various landscapes of imaginary sprites in nature. The compositional techniques include whole tone scale, octatonic scale, pentatonic scale, atonality, bitonality, polytonality, tone clusters, and minimalism. The piece’s orchestration style and techniques are mainly influenced by Stravinsky, Bartok, Schoenberg, Webern, Penderecki, Charles Ives, and Dinos Constantinides.

Part two is an analysis of the text …

Leveling The Viewing Field: The Impact Of Target Prevalence On Searcher's Functional Viewing Field, Juan D. Guevara Pinto

LSU Doctoral Dissertations

It is well known that target prevalence impacts various cognitive processes. In visual search, rare search targets are more difficult to detect than common targets. The present research investigated novel questions about target prevalence, focusing on observers’ functional viewing field (FVF) during passive search tasks. The FVF is the area in a display where attention is focused and item processing is enhanced. According the FVF framework (Hulleman & Olivers, 2017), the size of the FVF is modulated by the ease of target detections, such that visual search involving difficult target detection reduces the FVF. Although this would suggest that low …

Molecular Structure, Chemical Exchange, And Conductivity Mechanism Of High Concentration Litfsi Electrolytes, Susith R. Galle Kankanamge, Daniel G. Kuroda

Faculty Publications

© 2020 American Chemical Society. High concentration lithium electrolytes have been found to be good candidates for high energy density and high voltage lithium batteries. Recent studies have shown that limiting the free solvent molecules in the electrolytes prevents the degradation of the battery electrodes. However, the molecular level knowledge of the structure and dynamics of such an electrolyte system is limited, especially for electrolytes based on typical organic carbonates. In this article, the interactions and motions involved in lithium bis(trifluoromethanesulfonyl)imide in carbonyl-containing solvents are investigated using linear and time-resolved vibrational spectroscopies and computational methods. Our results suggest that the …

A Performer's Guide To "No Man In His Right Mind," "Letter," And "Mirror Mirror" From The Opera, Dog Days, Grace Claire Mccrary

LSU Doctoral Dissertations

Dog Days is a modern, American opera based in a war-torn, post-apocalyptic United States of America. Written by internationally acclaimed composer David T. Little and internationally acclaimed librettist Royce Vavrek, Dog Days is told through the eyes of a 13-year old girl, named Lisa. This project serves as a performer’s guide to Lisa’s three arias. Chapter one provides a biographical sketch of the composer, David T. Little. Chapter two briefly describes the life events of Royce Vavrek, leading to the development of Dog Days. Chapter three provides the detailed process of how the opera was created, specifically the development …

Conservation Potential And Mechanisms Of Avian Decline In Experimentally Fragmented And Regenerating Amazonian Rainforest, Cameron Lee Rutt

LSU Doctoral Dissertations

Twenty percent of the Brazilian Amazon has now been deforested, and deforestation rates are increasing. Yet the process of deforestation threatens biodiversity beyond the direct loss of habitat by inducing edge effects and creating forest fragments. In the tropics, among the most vulnerable birds to these human disturbances are a group of insectivorous species that forage on or near the ground. A variety of mechanisms have been proposed to explain these declines, but evidence for these hypotheses remains scare or equivocal. In this study, we examine three proposed mechanisms—physiological constraints to bright light, reduced breeding activity and nest success, and …

Finding Music In Chaos: Designing And Composing With Virtual Instruments Inspired By Chaotic Equations, Landon P. Viator

LSU Doctoral Dissertations

Using chaos theory to design novel audio synthesis engines has been explored little in computer music. This could be because of the difficulty of obtaining harmonic tones or the likelihood of chaos-based synthesis engines to explode, which then requires re-instantiating of the engine to proceed with sound production. This process is not desirable when composing because of the time wasted fixing the synthesis engine instead of the composer being able to focus completely on the creative aspects of composition. One way to remedy these issues is to connect chaotic equations to individual parts of the synthesis engine instead of relying …

Correctional Officers' Mental Health Literacy And Attitudes Toward Offenders With Mental Illness, Amber Rebecca Hebert

LSU Doctoral Dissertations

Overrepresentation of people with mental illness in the criminal justice system is a major societal problem. According to the Bureau of Justice Statistics, nearly three quarters of people housed in local jails report having symptoms suggestive of mental illness. Individual consequences to incarceration for people diagnosed with a mental illness include disruption in treatment, increase in symptomology, exposure to violence, and victimization. Correctional officers are an important component to the criminal justice system but their role in the lives of offenders with mental illness has been understudied. The current study explored the mental health knowledge, attitudes, and personal experiences of …

Association Of Apol1 Risk Genotype And Air Pollution For Kidney Disease, Ishan Paranjpe, Kumardeep Chaudhary, Manish Paranjpe, Ross O’Hagan, Sayan Manna, Suraj Jaladanki, Arjun Kapoor, Carol Horowitz, Nicholas Defelice, Richard Cooper, Benjamin Glicksberg, Erwin P. Bottinger, Allan C. Just, Girish N. Nadkarni

Faculty Publications

No abstract provided.

Natural Variation And Evolutionary Responses To Climate Change Stressors In Marine Invertebrates, Joanna Sarah Griffiths

LSU Doctoral Dissertations

Our rapidly changing climate is putting many species at risk of extinction and there is an urgent need to understand how species will respond to these changes. In this dissertation, I evaluate how three species of marine invertebrates (corals, oysters, and copepods) respond to stressful conditions in their current environments and how plasticity and evolutionary adaptation could alter their response to future climate change stressors. I first employed a space for time study to elucidate population differences in the response of cold-water corals, Balanophyllia elegans, to future ocean acidification. I found evidence that upwelling history (natural low pH exposure) influences …

Essays On Mortgage Portfolio Diversification, Timothy Patrick Dombrowski

LSU Doctoral Dissertations

Portfolios of mortgage loans played an important role in the Great Recession and continue to compose a material part of bank assets. The distribution of mortgage portfolio returns, and consequently, the risk of these portfolios, is quite distinct even from other fixed income asset classes. This dissertation contains three essays, each aiming to analyze a specific component of risk in mortgage portfolios and role of geographical diversification in reducing this risk.

The first essay investigates how cross-sectional dependence in the underlying properties flows through to the loan returns, and thus, the risk of the portfolio. In addition to demonstrating this …

The Seasonal Evolution Of Albedo Across Glaciers And The Surrounding Landscape Of Taylor Valley, Antarctica, Anna Bergstrom, Michael N. Gooseff, Madeline Myers, Peter T. Doran, Julian M. Cross

Faculty Publications

© Author(s) 2020. The McMurdo Dry Valleys (MDVs) of Antarctica are a polar desert ecosystem consisting of alpine glaciers, ice-covered lakes, streams, and expanses of vegetation-free rocky soil. Because average summer temperatures are close to 0 °C, the MDV ecosystem in general, and glacier melt dynamics in particular, are both closely linked to the energy balance. A slight increase in incoming radiation or change in albedo can have large effects on the timing and volume of meltwater. However, the seasonal evolution or spatial variability of albedo in the valleys has yet to fully characterized. In this study, we aim to …

An Improved Uniqueness Result For A System Of Sde Related To The Stochastic Wave Equation, Carl Mueller, Eyal Neuman, Michael Salins, Giang Truong

Journal of Stochastic Analysis

No abstract provided.

Effect Of Channelized And Unchannelized Lateral Outflow On Three-Dimensional Flow Structure And Sediment Transport Mechanisms In A River Delta, Mohammad Kifayath Chowdhury

LSU Master's Theses

Spatial and temporal patterns in three-dimensional flow structure have been linked to channel morphology and processes in many environments, including river meander bends, confluences-diffluences, and bedrock canyons. However, there is not yet an understanding of how channelized and gradual, distributed lateral outflows that are often prevalent in deltaic distributary systems influence three-dimensional flow structure and sediment transport mechanisms. This thesis presents an analysis of 3D flow structure data collected from Wax Lake Delta, a naturally developing river-dominated delta in the northern Gulf of Mexico. Three hydrographic surveys were conducted using boat-mounted acoustic Doppler current profiler (ADCP) at two sites: an …

Contextual Adjustment Of The Ite Trip Generation Rates Using Wi-Fi And Bluetooth Technologies, Saba Doulabi

LSU Master's Theses

The ITE Trip Generation Handbook has been in common use for about half a century to estimate vehicle trips generated by more than 172 land use categories as a function of establishment size (floor area) only. However, observed trip rates display a huge error range across different sites. Although contextual adjustment factors can ameliorate the error in the ITE trip generation estimates considerably, local site-specific trip generation rates should be collected for this purpose. Due to the huge time and monetary costs of data collection, adjusting the ITE trip generation rate is ignored by many jurisdictions. The primary contribution of …

Parkinson's Disease In Louisiana, 1999-2012: Based On Hospital Primary Discharge Diagnoses, Incidence, And Risk In Relation To Local Agricultural Crops, Pesticides, And Aquifer Recharge, Martin E. Hugh-Jones, R. Hampton Peele, Vincent L. Wilson

Faculty Publications

The two major causes of Parkinson's disease (PD) are genetic susceptibility and exposure to agricultural pesticides. Access to 23,224 individuals' hospital primary discharge diagnoses of PD allowed the mapping of cases against known crop distributions and pesticides. Our main objective was to map PD risks (cases per 10,000 people) against crops and their pesticides. The ZIP Code address locations, and the 2000 and 2010 census data, were used to map the risks of PD throughout Louisiana and in relation to United States Department of Agriculture (USDA)-recorded crops. The introduction of glyphosate-resistant crops appears to have initiated the PD disappearance from …

Genome-Wide Association Study To Identify Genetic Loci Associated With Gastrointestinal Nematode Resistance In Katahdin Sheep, G. M. Becker, K. M. Davenport, J. M. Burke, R. M. Lewis, J. E. Miller, J. L.M. Morgan, D. R. Notter, B. M. Murdoch

Faculty Publications

© 2020 The Authors. Animal Genetics published by John Wiley & Sons Ltd on behalf of Stichting International Foundation for Animal Genetics Resistance to gastrointestinal nematodes has previously been shown to be a moderately heritable trait in some breeds of sheep, but the mechanisms of resistance are not well understood. Selection for resistance currently relies upon faecal egg counts (FEC), blood packed cell volumes and FAMACHA visual indicator scores of anaemia. Identifying genomic markers associated with disease resistance would potentially improve the selection process and provide a more reliable means of classifying and understanding the biology behind resistant and susceptible …

Testing The Interaction Between The Cystic Fibrosis Transmembrane Regulator And Anoctamin 1 In Amacrine Cells Of Gallus Gallus Retinas, Hailey Danielle Simpson

Honors Capstones

No abstract provided.

Unreasonable People And The Possibility Of Liberal Containment, Cameron Simmons

Honors Capstones

No abstract provided.

Investigating The Origins Of Facultative Heterotrophy In Cyanobacteria, Emily A. Brown

Honors Capstones

No abstract provided.

Postmastectomy Radiotherapy For Left-Sided Breast Cancer Patients: Comparison Of Advanced Techniques, Yibo Xie, Daniel Bourgeois, Beibei Guo, Rui Zhang

Faculty Publications

Postmastectomy radiotherapy (PMRT) has been shown to improve the overall survival for invasive breast cancer patients, and many advanced radiotherapy technologies were adopted for PMRT. The purpose of our study is to compare various advanced PMRT techniques including fixed-beam intensity-modulated radiotherapy (IMRT), non-coplanar volumetric modulated arc therapy (NC-VMAT), multiple arc VMAT (MA-VMAT), and tomotherapy (TOMO). Results of standard VMAT and mixed beam therapy that were published by our group previously were also included in the plan comparisons. Treatment plans were produced for nine PMRT patients previously treated in our clinic. The plans were evaluated based on planning target volume (PTV) …

The Infrared View Of Dust And Molecules Around V4334 Sgr (Sakurai's Object): A 20-Yr Retrospective, A. Evans, R. D. Gehrz, C. E. Woodward, D. P.K. Banerjee, T. R. Geballe, G. C. Clayton, P. J. Sarre, S. Starrfield, K. Hinkle, R. R. Joyce, Foteini Lykou, L. A. Helton, S. P.S. Eyres, H. Worters, E. J. Montiel, T. Liimets, A. Zijlstra, M. Richter, J. Krautter

Faculty Publications

We present an analysis of the evolution of circumstellar dust and molecules in the environment of the very late thermal pulse object V4334 Sgr (Sakurai's object) over an ∼20-yr period, drawing on ground-, airborne-, and space-based infrared photometry and spectroscopy. The dust emission, which started in 1997, resembles a blackbody that cooled from ∼1200 K in 1998 August to ∼180 K in 2016 July. The dust mass, assuming amorphous carbon, was ∼5 × 10-10M⊙ in 1998 August, and we estimate that the total dust mass was ∼2 × 10-5M⊙ by ∼2016. The appearance of a near-infrared excess in 2008 suggests …

A Plethora Of New R Coronae Borealis Stars Discovered From A Dedicated Spectroscopic Follow-Up Survey, P. Tisserand, G. C. Clayton, M. S. Bessell, D. L. Welch, D. Kamath, P. R. Wood, P. Wils, Wyrzykowski, P. Mróz, A. Udalski

Faculty Publications

Context. It is more and more suspected that R Coronae Borealis (RCB) stars-rare hydrogen-deficient and carbon-rich supergiant stars-are the products of mergers of CO/He white-dwarf binary systems in the intermediate mass regime (0.6 < MTot < 1.2 M· ). Following the merger, a short-lived cool supergiant phase starts. RCB stars are extremely rare as only 77 have hitherto been known in the Galaxy, while up to 1000 have been predicted from population synthesis models. Aims. The goal is to significantly increase the number of known RCB stars in order to better understand their evolutionary paths, their spatial distribution, and their formation rate in the context of population synthesis results. A list of 2356 RCB star candidates was selected using infrared colours from the all-sky 2MASS and WISE surveys. The objective is to follow them up spectroscopically to classify the candidates and, thus, to distinguish RCB stars from other dust-producing stars. Methods. A series of brightness and colour-colour cuts that were used as selection criteria were then tested using the sample of known Galactic and Magellanic RCB stars. RCB spectral energy distribution models were also used to understand the effects of each selection criterion in terms of circumstellar shell temperature. Optical, low-resolution spectra were obtained for nearly 500 of the candidate stars. These spectra were compared to synthetic spectra from a new grid of MARCs hydrogen-deficient atmospheric models. This allowed us to define a spectroscopic classification system for RCB stars depending on their effective temperature and photometric status. Results. This programme has found 45 new RCB stars, including 30 Cold (4000 < Teff < 6800 K), 14 Warm (6800 < Teff < 8500 K), and one Hot (Teff > 15 000 K). Forty of these belong to the Milky Way and five are located in the Magellanic Clouds. We also confirmed that the candidate KDM 5651 is indeed a new RCB star, increasing the total number of Magellanic RCB stars to 30. Conclusions. We increased the total number of RCB stars known by ∼50%, bringing it up to 147. In addition, we compiled a list of …