Digital Commons Network^™

Industry Versus Government Regulation Of Food Date Labels: Observed Adherence To Industry-Endorsed Phrases, Brian E. Roe, Danyi Qi, Kathryn E. Bender, Julia Hilty

Faculty Publications

© 2019 by the authors. A leading factor in the creation of avoidable household food waste is confusion about food date labels. In the United States, date labels are largely unregulated, resulting in a plethora of date label phrases used in commerce. Federal regulation has been proposed but never passed, while both industry and government have provided voluntary guidance on preferred label phrases. We study food producer adherence to the label phrases endorsed by the Trading Partner Alliance (TPA, an industry group), which includes "Use By" for perishable products subject to a material degradation of critical performance or potential food …

Nonlinear Xuv Signal Generation Probed By Transient Grating Spectroscopy With Attosecond Pulses, Ashley P. Fidler, Seth J. Camp, Erika R. Warrick, Etienne Bloch, Hugo J.B. Marroux, Daniel M. Neumark, Kenneth J. Schafer, Mette B. Gaarde, Stephen R. Leone

Faculty Publications

Nonlinear spectroscopies are utilized extensively for selective measurements of chemical dynamics in the optical, infrared, and radio-frequency regimes. The development of these techniques for extreme ultraviolet (XUV) light sources facilitates measurements of electronic dynamics on attosecond timescales. Here, we elucidate the temporal dynamics of nonlinear signal generation by utilizing a transient grating scheme with a subfemtosecond XUV pulse train and two few-cycle near-infrared pulses in atomic helium. Simultaneous detection of multiple diffraction orders reveals delays of ≥1.5 fs in higher-order XUV signal generation, which are reproduced theoretically by solving the coupled Maxwell–Schrödinger equations and with a phase grating model. The …

Lignin-Polysaccharide Interactions In Plant Secondary Cell Walls Revealed By Solid-State Nmr, Xue Kang, Alex Kirui, Malitha C. Dickwella Widanage, Frederic Mentink-Vigier, Daniel J. Cosgrove, Tuo Wang

Faculty Publications

© 2019, The Author(s). Lignin is a complex aromatic biopolymer that strengthens and waterproofs plant secondary cell walls, enabling mechanical stability in trees and long-distance water transport in xylem. Lignin removal is a key step in paper production and biomass conversion to biofuels, motivating efforts to re-engineer lignin biosynthesis. However, the physical nature of lignin’s interactions with wall polysaccharides is not well understood. Here we show that lignin self-aggregates to form highly hydrophobic and dynamically unique nanodomains, with extensive surface contacts to xylan. Solid-state NMR spectroscopy of intact maize stems, supported by dynamic nuclear polarization, reveals that lignin has abundant …

Integrated Solid-State Nmr And Molecular Dynamics Modeling Determines Membrane Insertion Of Human Β-Defensin Analog, Xue Kang, Christopher Elson, Jackson Penfield, Alex Kirui, Adrian Chen, Liqun Zhang, Tuo Wang

Faculty Publications

© 2019, The Author(s). Human β-defensins (hBD) play central roles in antimicrobial activities against various microorganisms and in immune-regulation. These peptides perturb phospholipid membranes for function, but it is not well understood how defensins approach, insert and finally disrupt membranes on the molecular level. Here we show that hBD-3 analogs interact with lipid bilayers through a conserved surface that is formed by two adjacent loops in the solution structure. By integrating a collection of 13C, 1H and 31P solid-state NMR methods with long-term molecular dynamic simulations, we reveal that membrane-binding rigidifies the peptide, enhances structural polymorphism, and promotes β-strand conformation. …

A Review Of Interactions Between Insect Biological Control Agents And Semiochemicals, Anamika Sharma, Ramandeep Kaur Sandhi, Gadi V.P. Reddy

Faculty Publications

Biological control agents and semiochemicals have become essential parts of the integrated pest management of insect pests over recent years, as the incorporation of semiochemicals with natural enemies and entomopathogenic microbials has gained significance. The potential of insect pheromones to attract natural enemies has mainly been established under laboratory conditions, while semiochemicals from plants have been used to attract and retain natural enemies in field conditions using strategies such as trap crops and the push–pull mechanism. The best-known semiochemicals are those used for parasitoids–insect pest–plant host systems. Semiochemicals can also aid in the successful dispersal of entomopathogenic microbials. The use …

Adjective Learning In Young Typically Developing Children And Children With Developmental Language Disorder: A Retrieval-Based Approach, Laurence B. Leonard, Patricia Deevy, Jeffrey D. Karpicke, Sharon Christ, Christine Weber, Justin B. Kueser, Eileen Haebig

Faculty Publications

Purpose: There are strong retention benefits when learners frequently test themselves during the learning period. This practice of repeated retrieval has recently been applied successfully to children’s word learning. In this study, we apply a repeated retrieval procedure to the learning of novel adjectives by preschool-age children with developmental language disorder (DLD) and their typically developing (TD) peers. We ask whether the benefits of retrieval extend to children’s ability to apply the novel adjectives to newly introduced objects sharing the same characteristics as the objects used during the learning period. Method: Fourteen children with DLD (Mage = 62.64 months) and …

Effect Of Two Digestive Enzymes And Ph On The Dsrna Of Endornaviruses Of Bell Pepper And Melon Under In Vitro Conditions, Adair Mccanless, Allison Hultgren, Cesar Escalante, Alyssa Ardt, Rodrigo A. Valverde

Faculty Publications

Purpose: The objective of this investigation was to determine the in vitro effect of two common digestive enzymes, amylase and pepsin, and pH on the integrity of the RI dsRNA of bell pepper endornavirus (BPEV) and Cucumis melo endornavirus (CmEV) evaluated by gel electrophoresis and reverse-transcription PCR (RT-PCR). Methods: We conducted experiments on the in vitro effect of two common digestive enzymes, amylase and pepsin, and pH on the structural integrity of the replicative intermediate (RI) dsRNA of bell pepper endornavirus (BPEV) and Cucumis melo endornavirus (CmEV), evaluated by gel electrophoresis and reverse-transcription polymerase chain reaction. Result: The effect of …

The Marine Geological Imprint Of Antarctic Ice Shelves, James A. Smith, Alastair G.C. Graham, Alix L. Post, Claus Dieter Hillenbrand, Philip J. Bart, Ross D. Powell

Faculty Publications

Reductions in the thickness and extent of Antarctic ice shelves are triggering increased discharge of marine-terminating glaciers. While the impacts of recent changes are well documented, their role in modulating past ice-sheet dynamics remains poorly constrained. This reflects two persistent issues; first, the effective discrimination of sediments and landforms solely attributable to sub-ice-shelf deposition, and second, challenges in dating these records. Recent progress in deciphering the geological imprint of Antarctic ice shelves is summarised, including advances in dating methods and proxies to reconstruct drivers of change. Finally, we identify several challenges to overcome to fully exploit the paleo record.

Results From A 14-Year Intervention Program Designed To Impact Pursuit Of A Phd In Research Among Underrepresented Students In Stem Disciplines, Gretchen Schneider Burton, Eugene Kennedy, Maria Da Graça H. Vicente

Faculty Publications

Minority research and training (MRT) programs have been used across U.S. colleges and universities as a method to close the educational achievement gap and generate a highly skilled and diverse workforce. Previous studies have improved our understanding of the need to diversify the science, technology, engineering and mathematics (STEM) disciplines and the various interventions that have been developed to support these efforts. However, there is still little evidence about what strategies are most effective in promoting interest, continuation, and matriculation into STEM graduate programs among underrepresented groups. The study herein utilized a case study design with a mixed methods approach …

Apparatuses, Systems And Methods For Performing Remote Real-Time Experiments, Paulo J. Waltrich

College of Engineering Patents

Embodiments of the present invention include apparatuses and methods for performing remote experiments in real-time. The method includes sending requests to perform remote experiments for a desired configuration to a first and second facility. The desired configuration may include a first and second configuration. The method includes running a first remote experiment in real-time at the first facility to obtain a first output variable. The first facility may include the first configuration with a first input variable. The method includes simultaneously running a second remote experiment in real-time at a second facility to obtain a second output variable. The second …

@Houstonpolice: An Exploratory Case Of Twitter During Hurricane Harvey, Seungwon Yang, Brenton Stewart

Faculty Publications

Abstract

Purpose

The purpose of this paper is to examine the Houston Police Department (HPD)’s public engagement efforts using Twitter during Hurricane Harvey, which was a large-scale urban crisis event.

Design/methodology/approach

This study harvested a corpus of over 13,000 tweets using Twitter’s streaming API, across three phases of the Hurricane Harvey event: preparedness, response and recovery. Both text and social network analysis (SNA) techniques were employed including word clouds, n-gram analysis and eigenvector centrality to analyze data.

Findings

Findings indicate that departmental tweets coalesced around topics of protocol, reassurance and community resilience. Twitter accounts of governmental agencies, such as …

The Societal Collapse Of The Southern Lowland Maya Civilization: Don’T Miss The Forest For The Trees, Dwayne Hinton

Honors Capstones

No abstract provided.

Modeling And Simulations Of Peptoids, Pu Du

LSU Doctoral Dissertations

Polypeptoids, or poly-N-substituted glycines, are a class of sequence defined polymers that are structural mimics of polypeptides. Polypeptoids currently have received a growing interest due to their improved thermal stability, larger chemical diversity, and easier synthetic pathways as compared to peptides. Their lack of backbone hydrogen bonding and stereochemistry coupled with their easily tunability make them an ideal prototypical model system to study the effect of secondary/non-covalent interactions on self-assembly in solution. In order to develop a molecular level understanding of the effect of secondary interactions on polypeptoid self-assembly, systematic studies were carried out using molecular dynamics simulations on several …

Rfid Item-Level Tagging In A Grocery Store Environment, Brian Truman

LSU Master's Theses

The purpose of this research was to investigate how effective item-level Radio Frequency Identification (RFID) tagging would be using current RFID technology as a replacement for barcodes in a supermarket/grocery store environment.

To accomplish this, an experiment was be performed that utilized commercially available RFID technology. Passive Ultra High Frequency (UHF) RFID Tags were affixed to various grocery store items of different material categories (Food, Metal, Plastic, Liquid, and Glass), and placed in a metal shopping cart. Eight (8) antenna arrangements were created, comprised of different combinations of four (4) antennas in different locations around the cart.

The experiment was …

Race, Geography, And News Coverage Of The Opioid Epidemic, Nicholas B. Robert

LSU Master's Theses

The opioid epidemic is the deadliest drug epidemic in United States history. During the early stages of the epidemic, the focus was on white victims in rural and suburban areas. Using the geo-ethnic framework developed from immigration research, this study examines if geography and race impacted the framing of the opioid epidemic in newspapers. The study finds there to be a low level of geo-ethnic influenced framing in news coverage of the opioid epidemic from 2016-2018.

Supporting The Algebra I Curriculum With An Introduction To Computational Thinking Course, Michelle M. Laskowski

LSU Master's Theses

The Louisiana Workforce Commission predicts a 33.6% increase in computer science and mathematical occupations by 2022 and the Bureau of Labor Statistics foresees a 16% increase in computer scientists from 2018-2028. Despite these opportunities for job and financial security, the number of Louisiana students enrolled in a nationally accredited computing course is less than 1%, compared to national leaders California and Texas which have 3% and 3.8% of students respectively. Furthermore, the international assessments of mathematical literacy, PISA and TIMMS, both report American students continue to fall further behind their international peers in mathematics achievement.

This thesis rejects these statistics …

Simultaneous Enhancement Of Near-Infrared Emission And Dye Photodegradation In A Racemic Aspartic Acid Compound Via Metal-Ion Modification, Frank R. Fronczek, Jian Xu

Faculty Publications

Changing functionalities of materials using simple methods is an active area of research, as it is "green" and lowers the developing cost of new products for the enterprises. A new small molecule racemic N,N-dimethyl aspartic acid has been prepared. Its structure is determined by single-crystal X-ray diffraction. It is characterized by FTIR, XPS, 1 H NMR, and mass spectroscopy. Its near-infrared luminescence can be enhanced by the combination of metal ions, including Dy3+, Gd3+, Nd3+, Er3+, Sr3+, Y3+, Zn2+, Zr4+, Ho3+, Yb3+, La3+, Pr6+/Pr3+, and Sm3+ ions. An optical chemistry mechanism upon interaction between the sensitizer and activator is proposed. …

Dynamical Modeling In Cell Biology With Ordinary Differential Equations, Renee Marie Dale

LSU Doctoral Dissertations

Dynamical systems have been of interest to biologists and mathematicians alike. Many processes in biology lend themselves to dynamical study. Movement, change, and response to stimuli are dynamical characteristics that define what is 'alive'. A scientific relationship between these two fields is therefore natural. In this thesis, I describe how my PhD research variously related to biological, mathematical, and computational problems in cell biology. In chapter 1 I introduce some of the current problems in the field. In chapter 2, my mathematical model of firefly luciferase in vivo shows the importance of dynamical models to understand systems. Data originally collected …

From Piz Daint To The Stars: Simulation Of Stellar Mergers Using High-Level Abstractions, Gregor Dai, Parsa Amini, John Biddiscombe, Patrick Diehl, Juhan Frank, Kevin Huck, Hartmut Kaiser, Dominic Marcello, David Pfander, Dirk Pfüger

Faculty Publications

We study the simulation of stellar mergers, which requires complex simulations with high computational demands. We have developed Octo-Tiger, a finite volume grid-based hydrodynamics simulation code with Adaptive Mesh Refinement which is unique in conserving both linear and angular momentum to machine precision. To face the challenge of increasingly complex, diverse, and heterogeneous HPC systems, Octo-Tiger relies on high-level programming abstractions. We use HPX with its futurization capabilities to ensure scalability both between nodes and within, and present first results replacing MPI with libfabric achieving up to a 2.8x speedup. We extend Octo-Tiger to heterogeneous GPU-accelerated supercomputers, demonstrating node-level performance …

Examining Spatial Patterns Of Dominant Bunchgrass Species In Pine Savanna Groundcover Plant Communities, Katherine Anne Hovanes

LSU Doctoral Dissertations

Non-random spatial patterns within species are commonly observed in nature. Identifying spatial patterns of individuals within populations can give insight into processes regulating those populations and may indicate processes operating at community and ecosystem levels. Non-random spatial patterns of sessile organisms and dominant species are especially important for determining ecological processes structuring those populations. C₄ tussock-forming grasses (bunchgrasses) are dominant competitors and foundation species in pine savanna groundcover plant communities. Characterizing the spatial patterning of dominant bunchgrasses informs our understanding of processes regulating bunchgrass populations and indicates how bunchgrass populations may influence community assembly and ecosystem function in pine …

Managing Overheads In Asynchronous Many-Task Runtime Systems, Bibek Wagle

LSU Doctoral Dissertations

Asynchronous Many-Task (AMT) runtime systems are based on the idea of dividing an algorithm into small units of work, known as tasks. The runtime system is then responsible for scheduling and executing these tasks in an efficient manner by taking into account the resources provided to it and the associated data dependencies between the tasks. One of the primary challenges faced by AMTs is managing such fine-grained parallelism and the overheads associated with creating, scheduling and executing tasks. This work develops methodologies for assessing and managing overheads associated with fine-grained task execution in HPX, our exemplar Asynchronous Many-Task runtime system. …

Mini-Actors, Mega-Stages: Examining The Use Of Theatre Among Children And Youth In U.S. Evangelical Megachurches, Carla Elisha Lahey

LSU Doctoral Dissertations

How do children and youth first encounter the performing arts? While schools may stand out as an obvious answer, a recent study conducted by the U.S. Department of Education shows that the percentage of public schools offering theatre classes dropped at both the primary and secondary level from 2000-2010 (Brenchley). Yet, even as arts offerings experience a decline in some public schools, many students are being introduced to performance through another venue – the evangelical megachurch.

Since the birth of the church growth movement in the 1970s, megachurches (defined as Protestant congregations that average at least 2,000 weekly attendees) have …

Distributed Transactional Memory For Gpu Clusters, Samuel Oridge Irving

LSU Doctoral Dissertations

In this dissertation, we explore multiple designs for a Distributed Transactional Memory framework for GPU clusters. Using Transactional Memory, we relieve the programmer of many concerns including 1) how to move data between many discrete memory spaces; 2) how to ensure data correctness when shared objects may be accessed by multiple devices; 3) how to prevent catastrophic warp divergence caused by atomic operations; 4) how to prevent catastrophic warp divergence caused by long-latency off-device communications; and 5) how to ensure Atomicity, Consistency, Isolation, Durability for programs with irregular memory accesses. Each of these concerns individually can be daunting to programmers …

Social Justice Through Social Media: The Use Of Twitter As A Tool For Activism In The #Metoo #Blacklivesmatter Era, Laura L. Coleman

LSU Master's Theses

This study focuses on social justice and how people on Twitter chose to talk about it. The rise of social media has allowed Twitter users to speak more freely in more spaces than one. The study compared two different sexual assault cases between Judge Brett Kavanaugh and Professor Christine Blasey; and Virginia’s Lt. Governor Justin Fairfax and Vanessa Tyson. Applying the social responsibility theory, which allows free press without any censorship, I then can see the tone of which Black Twitter users have when talking about two separate sexual assault cases. This study compares the use of the #BlackTwitter hashtag …

Male Malady Modus Operandi: France's Evolving Gender Identity Crisis In The 19th Century, Victoria Rachelle Mosing

LSU Master's Theses

The following thesis analyzes, expands, and departs from Margaret Waller’s male malady theory, as she details in her article, “Cherchez La Femme: Male Malady and Narrative Politics in the French Romantic Novel.” Departures from Waller’s theory include the exploration of a dichotomous female protagonist and how her sexual presence threatens patriarchal order. Male protagonists, suffering from patriarchal alienation, must dispose of this female threat and thus restore order if they are to return to society. Using Atala by Chateaubriand, La fille aux yeux d’or by Honoré de Balzac, and Carmen by Prosper Mérimée as case studies, the thesis also argues …

Testing The Validity And Reliability Of Electromyography Acquisition Capabilities Of A Wearable Emg Device, Sense3, By Strive, Stanley Smith

LSU Master's Theses

There is a growing demand in the sports world for wearable technology, particularly those with electromyography acquisition capabilities. Electromyography (EMG) is technique for measuring the electrical activity that occurs during muscle contraction and relaxation. Basic practical applications of EMG use in sports include, but are not limited to: measuring activation timing of a muscle, measuring levels of activation, and detecting fatigue. The sports performance company Strive has designed an EMG wearable, called Sense3, that targets the following muscles of the lower limb: Quadriceps, Hamstrings, and Glutes. Sense3 must pass reliability assays to determine the validity of the EMG system in …

L'Apport Des Écrivains Catholiques Du Début Du Xxe Siècle Au Roman D'Analyse À Travers Leur Étude Du Mariage, Edouard D'Espalungue D'Arros

LSU Master's Theses

The psychological novel (roman d’analyse) as a genre starts in France with Mme de Lafayette (1634-1693) in the seventeenth century with the publication of La Princesse de Clèves (1678). However, the use of a psychological perspective is less known among early twentiethth century catholic authors. At the beginning of the century, several authors have used this genre extensively to convey their moral message: Paul Bourget (1852-1935); Henry Bordeaux (1870-1963); and Émile Baumann (1868-1941). The works of these writers have not been the object of research when it comes to analyzing their views and their accounts of their epoch. …

The Use Of Social Media In Emergency Management By Public Agencies And Non-Governmental Organizations: Lessons Learned From Areas Affected By Hurricanes Isaac, Sandy, And Harvey, Ryan Hamilton Kirby

LSU Doctoral Dissertations

Natural disasters are increasingly costly for the United States. The literature suggests emergency managers may improve disaster outcomes and enhance disaster resilience by supplementing their official public-communications methods with more bi-directional communication tactics using social media. This study aims to understand how social media is used within the “whole community” of emergency management in areas affected by recent hurricanes. The first research objective examines how social media is used by governmental and non-governmental organizations across the four phases of emergency management (preparedness, response, recovery, mitigation). The second objective is to identify challenges governmental and non-governmental groups have encountered and strategies …

Bio-Mechanical Characterization Of Adherent Cell Layers With A Pdms Cantilever, Merrel Truly Holley

LSU Doctoral Dissertations

In the last few decades, the mechanical characteristics of human cells has been linked to many physiological processes and pathological conditions, illustrating the importance as effective biomarkers. Mounting research has shown the mechanical force between cells and the extracellular matrix (ECM) plays a vital role in cellular processes such as tissue homeostasis, wound healing, cancer metastasis, and the progression of various diseases. This mechanical force, or the force that a cell produces on its surroundings, is termed as the cellular traction force (CTF). Precise characterization of the CTF can expand our knowledge of these important cellular processes as well as …

Shortest Path Calculation Using Contraction Hierarchy Graph Algorithms On Nvidia Gpus, Roozbeh Karimi

LSU Doctoral Dissertations

PHAST is to date one of the fastest algorithms for performing single source shortest path (SSSP) queries on road-network graphs. PHAST operates on graphs produced in part using Geisberger's contraction hierarchy (CH) algorithm. Producing these graphs is time consuming, limiting PHAST's usefulness when graphs are not available in advance. CH iteratively assigns scores to nodes, contracts (removes) the highest-scoring node, and adds shortcut edges to preserve distances. Iteration stops when only one node remains. Scoring and contraction rely on a witness path search (WPS) of nearby nodes. Little work has been reported on parallel and especially GPU CH algorithms. This …