Physical Sciences and Mathematics Commons^™

Breaking Coastal Hypoxia: Destratification Of Gulf Of Mexico Deadzone To Encourage Oxygen Transport Downwards To Maintain Marine Fauna, Veda Thipparthi

LSU Master's Theses

As a consequence of seasonal eutrophication and human input, a vast hypoxic area termed The Dead Zone develops every year in the Gulf of Mexico (GOM) during summer along the Louisiana coastline characterized by vertical seawater density-stratification with oxygen concentrations less than 2 mg.l^-1 at the seafloor. It poses a threat to bottom-dwelling faunae and their environment which has negative ecological and economic consequences. This project aims to mitigate hypoxia by employing mechanical impellers placed at strategic water depths and locations in the Gulf. Enhanced transport of oxygen results by mixing oxygen-enriched seawater at the surface, downward into the …

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 …

Changes In Students’ Mental Models From Computational Modeling Of Gene Regulatory Networks, Joseph Dauer, Heather E. Bergan-Roller, Gretchen P. King, Mckenzie Kjose, Nicholas J. Galt, Tomáš Helikar

School of Natural Resources: Faculty Publications

Background: Computational modeling is an increasingly common practice for disciplinary experts and therefore necessitates integration into science curricula. Computational models afford an opportunity for students to investigate the dynamics of biological systems, but there is significant gap in our knowledge of how these activities impact student knowledge of the structures, relationships, and dynamics of the system. We investigated how a computational modeling activity affected introductory biology students’ mental models of a prokaryotic gene regulatory system (lac operon) by analyzing conceptual models created before and after the activity.

Results: Students’ pre-lesson conceptual models consisted of provided, system-general structures (e.g., activator, repressor) …

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. …

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. …

The Application Of Gray-Scale Level-Set Method In Segmentation Of Concrete Deck Delamination Using Infrared Images, Chongsheng Cheng, Zhigang Shen

Department of Construction Engineering and Management: Faculty Publications

Conventional nondestructive delamination detection of concrete pavements through thermography is often based on temperature contrasts between delaminated and sound areas. Non-uniform backgrounds caused by the environmental conditions are often challenging for contrast-based methods to robustly differentiate the delaminated areas from the sound areas. Instead of focusing on the temperature contrast, this study proposes a temperature gradient-based level set method (LSM) to detect boundaries for delamination segmentations. A modified edge indicator function is developed to represent the normalized temperature gradient of a thermal image. The experimental study was conducted to evaluate its applicability and stability for boundary detection in terms of …

Biological And Practical Implications Of Genome-Wide Association Study Of Schizophrenia Using Bayesian Variable Selection, Benazir Rowe, Xiangning Chen, Zuoheng Wang, Jingchun Chen, Amei Amei

School of Medicine Faculty Publications

Genome-wide association studies (GWAS) have identified over 100 loci associated with schizophrenia. Most of these studies test genetic variants for association one at a time. In this study, we performed GWAS of the molecular genetics of schizophrenia (MGS) dataset with 5334 subjects using multivariate Bayesian variable selection (BVS) method Posterior Inference via Model Averaging and Subset Selection (piMASS) and compared our results with the previous univariate analysis of the MGS dataset. We showed that piMASS can improve the power of detecting schizophrenia-associated SNPs, potentially leading to new discoveries from existing data without increasing the sample size. We tested SNPs in …

Retrieval Of Intrinsic Mesospheric Gravity Wave Parameters Using Lidar And Airglow Temperature And Meteor Radar Wind Data, Robert Reichert, Bernd Kaifler, Natalie Kaifler, Markus Rapp, Pierre-Dominique Pautet, Michael J. Taylor, Alexander Kozlovsky, Mark Lester, Rigel Kivi

Publications

We analyse gravity waves in the upper-mesosphere, lower-thermosphere region from high-resolution temperature variations measured by the Rayleigh lidar and OH temperature mapper. From this combination of instruments, aided by meteor radar wind data, the full set of ground-relative and intrinsic gravity wave parameters are derived by means of the novel WAPITI (Wavelet Analysis and Phase line IdenTIfication) method. This WAPITI tool decomposes the gravity wave field into its spectral component while preserving the temporal resolution, allowing us to identify and study the evolution of gravity wave packets in the varying backgrounds. We describe WAPITI and demonstrate its capabilities for the …

Investigating The Origins Of Toxins Present In Electronic Cigarette Aerosols, Shawna Vreeke

Dissertations and Theses

The purported safety of electronic cigarettes has come under scrutiny with the significant increase of lung related illnesses starting in the summer of 2019. Public view has started to shift towards understanding the potential negative health impact associated with these devices. While many investigations indicate probable hazards present in e-cigarette aerosols, inter-laboratory assessments are wide ranging and can be contradictory. Due to the novelty of this field, relatively little is known about these products. In this work, the identification and quantification of inhalation toxicants such as formaldehyde, acrolein, acetaldehyde and dihydroxyacetone are reported. Results of the investigation of the ability …

Morphological Signatures Induced By Dust Back Reactions In Discs With An Embedded Planet, Chao-Chin Yang, Zhaohuan Zhu

Physics & Astronomy Faculty Research

Recent observations have revealed a gallery of substructures in the dust component of nearby protoplanetary discs, including rings, gaps, spiral arms, and lopsided concentrations. One interpretation of these substructures is the existence of embedded planets. Not until recently, however, most of the modelling effort to interpret these observations ignored the dust back reaction to the gas. In this work, we conduct local-shearing-sheet simulations for an isothermal, inviscid, non-self-gravitating, razor-thin dusty disc with a planet on a fixed circular orbit. We systematically examine the parameter space spanned by planet mass (0.1Mth ≤ Mp ≤ 1Mth, where Mth is the thermal mass), …

Non-Invasive Methods For Measuring And Monitoring Stress Physiology In Imperiled Amphibians, Edward J. Narayan, Zachery R. Forsburg, Drew R. Davis, Caitlin R. Gabor

School of Earth, Environmental, and Marine Sciences Faculty Publications and Presentations

Global climate change is negatively impacting global biodiversity and ectothermic vertebrates, with amphibians being the most imperiled vertebrate taxa. Increased mean global atmospheric temperatures, high rates of habitat degradation, and exposure to infectious diseases, such as chytridiomycosis, have contributed to population declines and extinctions of rare and endangered amphibian species. Field-based monitoring of physiological endocrine traits can help determine the sub-lethal effects of environmental stressors and provide early alerts when populations are chronically stressed. Recent advances in amphibian stress endocrinology include the development and use of non-invasive methods to quantify the glucocorticoid, or stress biomarker, corticosterone. Non-invasive methods, such as …

Wasp-52b. The Effect Of Star-Spot Correction On Atmospheric Retrievals, Giovanni Bruno, Nikole K. Lewis, Munazza K. Alam, Mercedes López-Morales, Joanna K. Barstow, Hannah R. Wakeford, David K. Sing, Gregory W. Henry, Gilda E. Ballester, Vincent Bourrier, Lars A. Buchhave, Ofer Cohen, Thomas Mikal-Evans, Antonio García Muñoz, Panayotis Lavvas, Jorge Sanz-Forcada

Information Systems and Engineering Management Research Publications

We perform atmospheric retrievals on the full optical to infrared (0.3−5μm⁠) transmission spectrum of the inflated hot Jupiter WASP-52b by combining HST/STIS, WFC3 IR, and Spitzer/IRAC observations. As WASP-52 is an active star that shows both out-of-transit photometric variability and star-spot crossings during transits, we account for the contribution of non-occulted active regions in the retrieval. We recover a 0.1–10× solar atmospheric composition, in agreement with core accretion predictions for giant planets, and no significant contribution of aerosols. We also obtain a star-spots, a measure which is likely affected by the models used to fit instrumental effects in …

High-Dimensional Clustering Method Based On Variant Bat Algorithm, Kou Guang, Guangming Tang, Jiajing He, Hengwei Zhang

Journal of System Simulation

Abstract: With the advent of the era of big data, the information resource is growing rapidly, and the data are becoming high-dimensional. Traditional clustering methods have a good effect for low-dimensional data, but no longer apply to high-dimensional data. On the basis of existing high-dimensional clustering algorithm, a high-dimensional clustering algorithm based on intelligent optimization SSC-BA is proposed. A novel objective function is designed, which integrates the fuzzy weighting within-cluster compactness and the between-cluster separation. A variant bat algorithm is introduced to calculate the weight matrix, giving the new learning rules. Simulation experiments are made for the proposed algorithm, and …

Sensing Optical Cavity Mismatch With A Mode-Converter And Quadrant Photodiode, Fabian Magana-Sandoval, Thomas Vo, Daniel Vander-Hyde, Jaclyn (Jax) Sanders, Stefan W. Ballmer

Physics Faculty Research and Publications

We present a new technique for sensing optical cavity mode mismatch and alignment by using a cylindrical lens mode converting telescope, radio-frequency quadrant photodiodes, and a heterodyne detection scheme. The telescope allows the conversion of the Laguerre-Gauss bullseye mode (LG₀₁) into the 45° rotated Hermite-Gauss (“pringle”) mode (HG₁₁), which can be easily measured with quadrant photodiodes. We show that we can convert to the HG basis optically, measure mode mismatched and alignment signals using widely produced radio-frequency quadrant photodiodes, and obtain a feedback error signal with heterodyne detection.

The Hydrogen Bond: A Hundred Years And Counting, Steve Scheiner

Chemistry and Biochemistry Faculty Publications

Since its original inception, a great deal has been learned about the nature, properties, and applications of the H-bond. This review summarizes some of the unexpected paths that inquiry into this phenomenon has taken researchers. The transfer of the bridging proton from one molecule to another can occur not only in the ground electronic state, but in various excited states as well. Study of the latter process has developed insights into the relationships between the nature of the state, the strength of the H-bond, and the height of the transfer barrier. The enormous broadening of the range of atoms that …

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 …

Graded Quivers, Generalized Dimer Models And Toric Geometry, Sebastián Franco, Azeem Hasan

Publications and Research

The open string sector of the topological B-model on CY (m+2)-folds is described by m-graded quivers with superpotentials. This correspondence extends to general m the well known connection between CY (m+2)-folds and gauge theories on the world-volume of D(5-2m)-branes for m = 0, ..., 3. We introduce m-dimers, which fully encode the m-graded quivers and their superpotentials, in the case in which the CY (m+2)-folds are toric. Generalizing the well known m = 1,2 cases, m-dimers significantly simplify the connection between geometry and m-graded quivers. A key …

Water‐Borne And Plasma Corticosterone Are Not Correlated In Spotted Salamanders, Alice R. Millikin, Sarah K. Woodley, Drew R. Davis, Ignacio T. Moore, James T. Anderson

School of Earth, Environmental, and Marine Sciences Faculty Publications and Presentations

Water‐borne hormone measurement is a noninvasive method suitable for amphibians of all sizes that are otherwise difficult to sample. For this method, containment‐water is assayed for hormones released by the animal. Originally developed in fish, the method has expanded to amphibians, but requires additional species‐specific validations. We wanted to determine physiological relevance of water‐borne corticosterone in spotted salamanders (Ambystoma maculatum) by comparing concentrations to those taken using established corticosterone sampling methods, such as plasma. Using a mixture of field and laboratory studies, we compared water‐borne corticosterone levels to other traditional methods of sampling corticosterone for spotted salamander larvae, metamorphs, and …

Sample Transfer Optimization With Adaptive Deep Neural Network, Hemanta Sapkota, Md Arifuzzaman, Engin Arslan

Computer Science Faculty Research & Creative Works

Application-layer transfer configurations play a crucial role in achieving desirable performance in high-speed networks. However, finding the optimal configuration for a given transfer task is a difficult problem as it depends on various factors including dataset characteristics, network settings, and background traffic. The state-of-the-art transfer tuning solutions rely on real-time sample transfers to evaluate various configurations and estimate the optimal one. However, existing approaches to run sample transfers incur high delay and measurement errors, thus significantly limit the efficiency of the transfer tuning algorithms. In this paper, we introduce adaptive feed forward deep neural network (DNN) to minimize the error …

Investigations Of Aerobic Methane Oxidation In Two Marine Seep Environments: Part 1—Chemical Kinetics, Eric W. Chan, Allan M. Shiller, Dongjoo J. Joung, Eleanor C. Arrington, David L. Valentine, Molly C. Redmond, John A. Breier, Scott A. Socolofsky, John D. Kessler

School of Earth, Environmental, and Marine Sciences Faculty Publications and Presentations

Microbial aerobic oxidation is known to be a significant sink of marine methane (CH4), contributing to the relatively minor atmospheric release of this greenhouse gas over vast stretches of the ocean. However, the chemical kinetics of aerobic CH4 oxidation are not well established, making it difficult to predict and assess the extent that CH4 is oxidized in seawater following seafloor release. Here we investigate the kinetics of aerobic CH4 oxidation using mesocosm incubations of fresh seawater samples collected from seep fields in Hudson Canyon, U.S. Atlantic Margin and MC118, Gulf of Mexico to gain a fundamental chemical understanding of this …

Afternoon Keynote: How Climate Change Impacts Are Considered In The Credit Rating Process, Leonard Jones

Virginia Coastal Policy Center Annual Conference

No abstract provided.

Tumor Dynamics Under Immunotherapy: A Time-Delay Revised Predator-Prey Model, Emma A. Turian

Faculty Research and Creative Activities Symposium

Cancer remains a leading cause of death worldwide and traditional treatments such as surgical resection, chemotherapy, and radiotherapy may have limited benefits depending on the type of cancer and the stage at which it is diagnosed. Immunity is the state of protection against foreign pathogens or substances (i.e., antigens). Recent research into novel approaches to treatment has suggested that immunotherapy, which aims to optimize the body’s own natural responses to combating disease through various mechanisms, may be a promising strategy that can improve prognosis for certain cancer types that are refractory to other treatment options. Quantitative models simulating the dynamics …

High Multiplicity Strip Packing Problem With Three Rectangle Types, Andy Yu

Electronic Thesis and Dissertation Repository

The two-dimensional strip packing problem (2D-SPP) involves packing a set R = {r₁, ..., r_n} of n rectangular items into a strip of width 1 and unbounded height, where each rectangular item r_i has width 0 < w_i ≤ 1 and height 0 < h_i ≤ 1. The objective is to find a packing for all these items, without overlaps or rotations, that minimizes the total height of the strip used. 2D-SPP is strongly NP-hard and has practical applications including stock cutting, scheduling, and reducing peak power demand in smart-grids.

This thesis considers …

Arsenoplatins - Potent Anticancer Agents Against Triple-Negative Breast Cancer, Denana Miodragovic

Faculty Research and Creative Activities Symposium

Triple-negative breast cancer (TNBC) is a more aggressive breast cancer with a poorer prognosis than other types of breast cancer. TNBC mortality is 42% higher in African American women compared to other American women, which is one of the most significant examples of racial disparity in oncology. TNBC does not express the common receptors estrogen and progesterone or the human epidermal growth factor receptor 2 (HER2), making targeted hormone therapies ineffective. Thus, there is an urgent medical need for the development of novel potential drug candidates for TNBC. In clinics, platinum-based regimes provide overall survival advantages for TNBC patients compared …

Internet Searching Behaviors Of Low Literacy Breast Cancer Survivors, Francisco D. Iacobelli, Ginger L. Dragon, Giselle Mazur, Judy Guitelman

Faculty Research and Creative Activities Symposium

Internet searching is a popular tool for patients to find health-related information. However, low literacy individuals are at a disadvantage with respect to their ability to evaluate online health information. When using common web search engines to find health information, behaviors such as misspelling, misappropriation of words and incomplete search queries can result in inadequate results and misleading information. The goal of this research is to understand the search strategies and common mistakes that low-literacy Latina breast cancer survivors exhibit when searching for information online in order to inform future information seeking interfaces. To explore search behaviors online we asked …

Newton’S Iteration At Nonisoated Solutions, Zhonggang Zeng

Faculty Research and Creative Activities Symposium

Newton’s iteration is arguably the most important and fundamental method for solving systems of nonlinear equations with a long and fascinating history. Its local quadratic convergence to isolated nonsingular solutions is well documented in the literature. It is also well-known that the iteration loses its quadratic rate of convergence, if it applies and converges at all, to nonisolated solutions with a dismal attainable accuracy in numerical computation. Even though solving systems of nonlinear equations is a standard topic in textbooks of numerical analysis, the elaboration has always been limited to isolated solutions. Models with nonisolated solutions frequently arise in applications. …

On The Apparent Attractive Interaction Between Colloidal Particles Of Like Charge, Stefan Tsonchev

Faculty Research and Creative Activities Symposium

A new attractive force between colloidal particles of like charge has been discovered. This force is of entropic depletion origin, and is exhibited between colloidal particles in electrolyte solution. The attractive potential associated with this force is a function of the electrolyte concentration, and can have a minimum up to the order of -10 kT deep for certain parameters of the system. Implications of the force to various systems of interest will be discussed.

Monitoring The Breakdown Of Plastic Materials Under Ultraviolet And Visible Light, Samantha Brown-Xu

Faculty Research and Creative Activities Symposium

The accumulation of plastic waste in landfills and especially in water systems is a pressing environmental concern. Every year, roughly 8 million tons of plastic waste escapes into the oceans, which over time can then break down into microplastics, less than a quarter inch in size, that are consumed by ocean wildlife. The plastic degradation can occur by mechanical means, but energy absorbed from sunlight is also involved in the breakdown of plastic materials. If the efficiency of this degradation was increased, solar energy could be used to eliminate plastic waste and regenerate fuels or chemical feedstocks. In this study, …

Integrating Problem Solving, Coding, Mathematics, And Pedagogy, John F. Erickson

Faculty Research and Creative Activities Symposium

We present a case study illustrating an integrated approach to the teaching of problem solving, computation, and mathematics. This approach combines ideas from Polya, Ross, and Moore about mathematical pedagogy with a heavy dose of computer assisted calculation in the spirit of experimental mathematics facilitated by the rapid prototyping environment of Mathematica which is ideal for an exploratory approach to learning. Essentially, students learn math and programming the same way mathematicians do research and we believe that this can scale all the way from grammar school to graduate school. To be more specific, we start with an elementary recreational math …

Guiding Us Throughout A Sea Of Data - A Survey On Recommender Systems And Its Privacy Challenges, Xiwei Wang, Marcelo O. Sztainberg

Faculty Research and Creative Activities Symposium

Over the past decades, the Internet has served as the backbone connecting people to others, places and things. With the sheer volume of information generated everyday, people can feel overwhelmed when having to make a selection among the multiple options that normally come up after a search or application request. For example, when searching for news articles regarding a particular topic, the search engine will present a number of results to you. When looking for some product on shopping websites, there are usually several pages of results that match the keywords. It can be very challenging for people to find …