Physical Sciences and Mathematics Commons^™

Magnetic Resonance Elastography Of The Brain Using An Ergonomic Driver: Assessment Of Scan-Rescan Reproducibility, Hatim Chafi

LSU Master's Theses

Magnetic resonance elastography (MRE) allows the visualization of displacement patterns from induced harmonic mechanical waves propagating in tissue. Strain and mechanical properties can be computed from these displacement patterns. Mechanical properties of tissue are affected by various disease processes. MRE has shown brain tumor to differ in stiffness in comparison to normal tissue. MRE is currently being offered as an upgrade on most conventional MRI scanners. However, the actuator supplied by vendors is a drum driver designed primarily for hepatic MRE scan. The goals of the project was to design and build an ergonomic flexible driver for use in MRE …

Fish Biomass And Community Structure Around Standing And Toppled Oil And Gas Platforms In The Northern Gulf Of Mexico Using Hydroacoustic And Video Surveys, Emily Marissa Reynolds

LSU Master's Theses

There has been relatively little study of the efficacy of decommissioned oil and gas platforms as artificial reef habitats for fish assemblages in the northern Gulf of Mexico (GOM). A variety of fish species have been reported on these structures, but the species biomass distribution and community structure has not been studied thoroughly. Hydroacoustic and video surveys were conducted quarterly from June 2013 to June 2014 at three standing and two toppled oil and gas platforms located approximately 130 km off the coast of Louisiana at 90 m depth; to gain information about the spatial biomass distribution and community structure …

Fish Assemblage Response To Environmental Gradients And Altered Dendritic Connectivity In The Red River Basin, Central Louisiana, Catherine Nell Reuter

LSU Master's Theses

Louisiana’s small streams provide critical habitat for diverse ecologically and economically important fish species. However, the relationship between these fish assemblages and habitat variables remains poorly understood. The role of anthropogenic alteration of dendritic stream connectivity is of specific interest and has been shown to significantly influence stream ecology. This study explored the interaction among watershed characteristics, stream connectivity, stream physico-chemistry, and fish assemblages in little-studied Red River basin of central Louisiana as well as how reservoir littoral zones compared to streams, both in terms of fish assemblage and habitat. Fish and habitat were sampled in 21 headwater streams, half …

Oil And Gas Platforms On Ship Shoal, Northern Gulf Of Mexico As Habitat For Reef-Associated Organisms, David Bradley Reeves

LSU Master's Theses

Nearshore Louisiana has experienced substantial changes within the last half-century, including the annual formation of the world’s second largest hypoxic zone and the construction of thousands of oil and gas platforms (rigs). Ship Shoal and its rigs may provide important substrate in nearshore Louisiana because rigs act as de facto artificial reefs and the shoal’s bottom waters were well oxygenated on 43% of days when surrounding areas were hypoxic. From July to September of 2014, fish assemblages and hydrography were compared at shoal rigs, rigs inshore of the shoal, and rigs offshore of the shoal, and stone crab populations were …

String Searching With Ranking Constraints And Uncertainty, Sudip Biswas

LSU Doctoral Dissertations

Strings play an important role in many areas of computer science. Searching pattern in a string or string collection is one of the most classic problems. Different variations of this problem such as document retrieval, ranked document retrieval, dictionary matching has been well studied. Enormous growth of internet, large genomic projects, sensor networks, digital libraries necessitates not just efficient algorithms and data structures for the general string indexing, but indexes for texts with fuzzy information and support for queries with different constraints. This dissertation addresses some of these problems and proposes indexing solutions. One such variation is document retrieval query …

Population Abundance And Transience Of Selected Coastal Plain Crayfishes, Samantha Lott

LSU Master's Theses

Crayfish are important for stability, determining ecosystem structure, and ecosystem functions in freshwater habitats. Louisiana has many endemic species of crayfish, but most are poorly described. This study investigated the populations of some of the lesser known crayfishes in the South Central Plains. Specifically, the goals were to examine movement, movement across anthropogenic barriers, and estimate population size of 10 species reported from the area: Procambarus natchitochae, P. vioscai, P. clarkii, P. acutus, P. zonangulus, P. tulanei, P. kensleyi, Orconectes maletae, O. lancifer, and O. palmeri. In combination with a field team, I sampled twelve wadeable streams with DC backpack …

Planktonic Influence On The Toxicity Of Hewafs (High-Energy Water Attenuated Fractions), Erin Elizabeth Saal

LSU Master's Theses

The Deep Water Horizon oilrig explosion led to the release of 6.8 ± 1.7 x 108 kg or 4.9 million barrels of petroleum hydrocarbons into the Gulf of Mexico. The spill persisted from the end of April to mid July 2010 affecting a significant portion of the Gulf coast. The effects of this spill are being studied in labs across the country, and this thesis investigated high-energy water accommodated fractions (HEWAFs) as a potential tool for use in this effort. Water accommodated fractions (WAFs) are mediums containing only the fraction of petroleum that remains in aqueous phase after a mixing …

Pytracks: A Tool For Visualizing Fish Movement Tracks On Different Scales, Ross Fossum

LSU Master's Theses

A fundamental problem in conservation biology and fisheries management is the ability to make educated decisions based on the data collected. Fish populations and their spatial distributions need to be represented accurately for conversation efforts and management decisions. Methods such as modeling, surveying, and tracking can all be used to collect data on a particular fishery. To include the movement patterns in conservation and management, one needs to work with and process fish tracking data or data exported from fish movement simulation models. This data can often be difficult to process. This topic is becoming increasingly popular as technology to …

A Critique Of A Student-Centered Learning Approach Used In A Geometry Classroom, Alana Blackwell Day

LSU Master's Theses

This thesis offers a framework for identifying effective classroom materials to support student-centered learning. Based on a review of published studies on effective classroom activities, as well as theses by Louisiana Math and Science Teachers Institute (LaMSTI) graduates, we identify promising characteristics. We employed these in five lessons, refined them into questions, and offer in final form for use.

Partial Cosine-Funk Transforms At Poles Of The Cosine-Λ Transform On Grassmann Manifolds, Christopher Adam Cross

LSU Doctoral Dissertations

The cosine-λ transform, denoted C^λ, is a family of integral transforms we can define on the sphere and on the Grassmannian manifolds of p-dimensional subspaces in Kⁿ where K is R, C or the skew field H of quaternions. We treat the Grassmannians as the symmetric spaces SO(n)/S(O(p) × O(q)), SU(n)/S(U(p) × U(q)) and Sp(n)/(Sp(p) × Sp(q)) and we work by analogy with the case of the cosine-λ transform on the sphere, which is also a symmetric space.

The family C^λ extends meromorphically in λ to the complex plane with poles at (among other values) λ …

Writing In The Geometry Classroom, Amy Lynn Rome

LSU Master's Theses

This study sought a time-efficient way to implement writing in ninth-grade Geometry. Students wrote responses to five expository writing prompts spread out over the spring semester of the 2014-2015 school year. Students’ first attempts were graded and returned to them along with feedback in the form of a teacher-written exemplar. Students rewrote assignments to improve their grades. All first and second attempts were collected and evaluated. We found that students were more successful after seeing the exemplar. Moreover, on assignments occurring later in the semester, more students were able to score in the top categories of the writing assignments on …

The Implementation Of Two Cooperative Learning Structures, Rally Coach And Teams-Games-Tournaments, In High School Chemistry Courses, Joanna Miketinas Stewart

LSU Master's Theses

To combat the obstacles that students experience in chemistry, two cooperative learning strategies, Rally Coach and Teams-Games-Tournaments, were implemented in five chemistry courses at East Ascension High School. Rally Coach called for two students to work as a pair and peer tutor to successfully complete practice problems for each lesson. Teams-Games-Tournaments required students to work in groups of four to complete practice problems and compete for team points as a review. Every student experienced both learning strategies. A comparison was made to see which cooperative learning strategy better helped student performance, including comparisons of effects on different student demographics and …

Metacommunity Dynamics And The Biogeography Of Central Louisiana Crayfishes, William Robert Budnick

LSU Master's Theses

The greatest diversity of crayfishes, especially of rare Orconectes species, is found in the central Louisiana watersheds (Red River, Mermentau, Calcasieu, and Vermillion-Teche), and most species are widely distributed among the drainages. The purpose of this research was to lay groundwork for species distribution and metacommunity modelling for crayfishes in this region. To address this goal, two field studies were performed in the summers of 2013 and 2014, as well as an indoor laboratory study. Analyses of broadly distributed species indicated no significant correlations between species abundances and habitat variables nor any significant environmental gradients for those species. Within-drainage variability …

Interpretation Of Geochemical Signatures From Modern Carbonate Springs To The Rock Record, Benjamin Maas

LSU Doctoral Dissertations

Despite the importance of carbonate aquifers as reservoirs of oil, of water, and of carbon dioxide, questions remain about the diagenetic processes that enhance porosity and permeability. Some of the questions are: 1) what are the water-rock interactions that control the geochemistry of spring waters; 2) are the geochemical signatures of saline-fresh water mixing zones preserved in the carbonate rock record; and 3) how much carbon dioxide outgases along spring runs? To address these questions, two field sites, one in Oklahoma (the site of an active saline-fresh water mixing zone) and the other in Colorado, the location of a former …

Advanced Math Curriculum - Act Prep And Pre-College Algebra, Lauren Louise Morris

LSU Master's Theses

The purpose of this thesis was to create a non-traditional Advanced Mathematics course paired with Math XL® for School (MXL) for senior-level students with low ACT Math scores. The Advanced Math course was created with the purpose of helping students increase their ACT Math scores and preparing them for first-year college math, College Algebra. The course was taught at a private high school in Louisiana for the 2014-2015 school year and is attached to this thesis as an appendix. Upon completion of this course, the participating students achieved an average increase of 3.1 points in their ACT Math scores. After …

Toxic Landscapes, Environmental Justice, And The Community: An Assessment Of Citizen Participation In Superfund Site Remediation Across Vulnerable Populations, Simone Justine Domingue

LSU Master's Theses

The environmental justice movement has made progress toward unveiling environmental inequalities and addressing these inequalities through the empowerment of low-income and minority communities. Federal agencies like the EPA have incorporated environmental justice principles into their operating frameworks, with the goals of ensuring every community is treated similarly when it comes to the implementation of environmental statutes, and ensuring community members are active participants in environmental activities that affect community well-being. Community involvement at federal Superfund sites is rarely conceptualized as an event related to environmental justice despite the role it has in shaping decisions at hazardous waste sites. This study …

Wading Bird Food Availability In Rice Fields And Crawfish Ponds Of The Chenier Plain Of Southwest Louisiana And Southeast Texas, Cullen C. Foley

LSU Master's Theses

Wading birds in southwestern Louisiana and southeastern Texas rely heavily on rice fields and crawfish ponds as foraging areas; however, little information exists on food availability throughout the annual crop cycle. The objectives of this study are: 1) Develop a classification for rice and crawfish fields based upon tillage, forage crop (for crawfish fields), water depths, vegetation density, vegetation height, and other visible parameters; 2) Quantify the distribution of rice and crawfish fields in various stages across the landscape through time; 3) Determine the effects of rice and crawfish field types and landscape characteristics on wading bird use; and, 4) …

Otoliths Then And Now: A Study Of Ancient And Modern Fish Populations In Louisiana's Coastal Waters, Marshall James Kormanec

LSU Master's Theses

Fish otoliths are composed of inorganic calcium carbonate that aid in gravity and auditory reception. Substances permanently accrete to otolith surfaces in distinct temporal patterns of alternating opaque and translucent rings; these rings are direct proxies for a fish’s age. The objective of my research is to demonstrate how otoliths can be used through time and space to estimate both age and growth of fish. I investigated the spatial differences in age distributions and growth models for red snapper, Lutjanus campechanus, at four natural shelf-edge reefs in the northwestern Gulf of Mexico. Red snapper cohorts ranged 1987-2010 cohorts, with the …

The Correlation Between Parental Involvement And Student Academic Achievement, Damien Ramon Antoine

LSU Master's Theses

This study investigates whether or not there is a correlation between parental involvement and student academic achievement. A sample of 103 students at Madison Preparatory Academy and CSAL Middle School (CSAL, Inc) were tested for correlations between the degree with which their parents are engaged in their academic lives and the success that they achieve as a result. Small correlations were found to exist between some of the variables tested. The test group consisted of a group of high school students from Madison Preparatory Academy (MPA) and their siblings who attended CSAL Middle which is the feeder school for MPA. …

Caspar: Congestion Avoidance Shortest Path Routing For Delay Tolerant Networks, Michael F. Stewart

LSU Master's Theses

Unlike traditional TCP/IP-based networks, Delay and Disruption Tolerant Networks (DTNs) may experience connectivity disruptions and guarantee no end-to-end connectivity between source and destination. As the popularity of DTNs continues to rise, so does the need for a robust and low latency routing protocol capable of connecting not only DTNs but also densely populated, dynamic hybrid DTN-MANET. Here we describe a novel DTN routing algorithm referred to as Congestion Avoidance Shortest Path Routing (CASPaR), which seeks to maximize packet delivery probability while minimizing latency. CASPaR attempts this without any direct knowledge of node connectivity outside of its own neighborhood. Our simulation …

A Palynological Analysis Of Seymour Island And King George Island Off The Antarctic Peninsula: A Dating And Climatic Reconstruction, Caven Madison Kymes

LSU Master's Theses

During the Cretaceous and early Paleocene, Antarctica was covered by lush vegetation. However, Antarctica today is covered with ice and snow leaving less than 1% of the continent inhabited by vegetation. By studying this decline in vegetation and reconstructing past environments, we can gain a better understanding of environmental changes and use this knowledge to predict future changes. In this thesis, I present my results and interpretations of palynological changes across the Antarctic Peninsula during the Late Eocene, Middle Oligocene, and Miocene. The first study discusses a paleoenvironmental reconstruction of the upper La Meseta formation (Late Eocene), Seymour Island, and …

A Study Of Mathematical Equivalence: The Importance Of The Equal Sign, Christy De'sha Duncan

LSU Master's Theses

The purpose of this study was to investigate students’ understanding and knowledge of the equal sign, so that instructional resources could be identified to improve student’s conceptual understanding about mathematical equivalence. A test, consisting of a combination of items taken from previous studies, as well as items developed by the researchers, was designed to gauge students’ understanding of the equality symbol. The test was administered to 54 seventh-graders in Spring 2015. The results of the test indicated a significant number of students in our district have a limited understanding of mathematical equivalence. This papers ends with some suggested activities recommended …

Hydrological Influences On Catahoula Lake In An Altered Floodplain, Lincoln Dugue

LSU Master's Theses

Floodplain lakes in floodplains of large rivers undergoing intensive alterations are subject to hydrologic alteration. One example is in the Lower Mississippi Alluvial Valley (LMAV) and pivotal habitat for wildlife. Catahoula Lake has experienced hydrologic regime alterations over the past ~150 years that may be contribute to changes in the habitat with expansion of woody plants. A Diversion Channel was constructed in 1972 to provide the natural, annual de-watering of the lake to maintain its ecological integrity, but ecologic changes are still occurring. Our general goal is to understand the hydrologic regime of the lake, particularly the historical hydrologic regime …

Impact Of Multileaf Collimator Configuration Parameters On The Dosimetric Accuracy Of 6-Mv Intensity-Modulated Radiation Therapy Treatment Plans, Nicholas Colin Petersen

LSU Master's Theses

Purpose: To improve the dosimetric accuracy of intensity modulated radiation therapy (IMRT) dose distributions as calculated by the treatment planning system (TPS) by optimizing the parameters that govern multileaf collimator (MLC) transmission and rounded leaf offset. Methods: The MLC leaf transmission was optimized based on measurements made with ionization chambers and radiographic film. The rounded leaf offset table was optimized by measuring the radiation field edge as a function of leaf bank position with an ionization chamber in a water scanning tank and comparing the location to TPS equivalent dose calculations. Optimizations were validated by performing IMRT quality assurance (QA) …

Phylogenetic Tree Construction For Starfish And Primate Genomes Via Alignment Free Methods, Ambujam Krishnan

LSU Master's Theses

A phylogenetic tree is a tree like diagram showing the evolutionary relationship among various species based on their differences or similarity in their physical or genetic makeup.The similarity in their genetic makeup is traditionally measured based on pairwise distance between their gene sequences using sequence alignment methods. Due to the advancement in next generation sequencing technologies there is a huge amount of datasets available for partially or completely sequenced genomes. These massive datasets requires a faster comparison methods other than the traditional alignment-based approaches. Therefore, alignment free approaches are gaining popularity in recent years. In this thesis, we compare alignment-based …

Tracing Sediment In The Subsurface Using Beryllium-7: Green River Basin, Ky, Caroline Adams Broderick

LSU Master's Theses

As water flows through areas of limestone, karst inevitably develops, creating sinking streams and sinkholes that transport alumino-silicate particles from the surface into the subsurface. Sediment budget studies on short term scales through karst are rare. Thus, a feasibility study using beryllium-7 (7Be), which attaches to soil particles and can be used as a short-term (2-3 month) tracer of the movement of fine-grained sediment in karst was investigated. Sediment samples were collected from a karstic catchment within Green River basin, Kentucky, both on the surface and in the subsurface along a cave stream. Samples were collected prior to and immediately …

Chlorine Enrichment Of Hydrous Minerals In Archean Granulite Facies Ironstone From The Beartooth Mountains, Montana, Usa: Implications For High-Grade Metamorphic Fluids, Nicholas Michael Daigle

LSU Master's Theses

The amount of chlorine present in hydrous minerals influences mineral stability and may serve as a monitor of the evolving fluid phase during progressive metamorphism. Chlorine contents of amphibole and biotite vary as a function of temperature, pressure, crystallochemical factors, and fluid composition. The sensitivity of these minerals to serve as a monitor of Cl in aqueous fluids is particularly effective in Fe-rich amphibole and biotite such as those found in ironstones. Ironstones from the eastern Beartooth Mountains, Montana are typified by dominantly anhydrous mineral assemblages of quartz + magnetite + orthopyroxene + garnet ± clinopyroxene and have equilibrated during …

Distribution Of Uranium In A Black Shale Across The Shelf Of The Late Pennsylvanian Midcontinent Sea, Maxwell A. Lindaman

LSU Master's Theses

Uranium paleoredox proxies such as enrichment factors and 238U/235U ratios can be used to reconstruct redox conditions in ancient water masses on local and global scales based on the differential behavior of uranium in oxic, suboxic, and anoxic environments. Many studies have focused on black shales due to their high levels of metal enrichment and association with climactic events. However, the influence of local effects on uranium accumulation is uncertain, particularly in ancient epeiric sea environments. This study consists of two parts: an evaluation of common sequential extraction methods for U analysis (particularly the Tessier-type sequential extraction) and the application …

Habitat Preferences Of Adult Spotted Seatrout, Cynoscion Nebulosus, In Lake Pontchartrain, Louisiana, Noelle Marie Bramer

LSU Master's Theses

Spotted seatrout (Cynoscion nebulosus) are a highly sought after sportfish, making up over 90% of the recreational fishery in Louisiana. As a significant portion of every life history stage is spent within its natal estuary, it is an ideal bio-indicator of estuarine health. As one of the largest estuaries in Louisiana, Lake Pontchartrain represents one such supporting ecosystem. From November 2012 to April 2014 acoustic tagging of individual fish, a lake-wide receiver array, and ArcGIS mapping software were utilized to determine the spatial distribution of spotted seatrout within the lake. Receivers were placed in representative locations including man-made and natural …

Development Of New Linking Chemistry With The Fac-{Re(Co)3}+ Core For Eventual Applications In Radiopharmaceuticals In Imaging And Therapy, Aponsu Meregngna Pramuditha Lakmi Abhayawardhana

LSU Doctoral Dissertations

The facile labeling of biomolecules with a radionuclide is a key goal in radiopharmaceutical development. This study explores two different ligand systems for fac-[Re(CO)3L]+ complexes, that could be used in bioconjugation. The first approach uses a tridentate ligand having a sulfonamide linkage and modeled on previously evaluated fac-[Re(CO)3(N(SO2R)dpa)]PF6 complexes. The present goal was to develop new related sulfonamide complexes with more hydrophilic ligands designed to avoid the bioavailability problems that would plague the N(SO2R)dpa ligand system. A series of fac-[Re(CO)3(N(SO2R)dien)]PF6 complexes with different R groups linked to the central nitrogen of a symmetric tridentate sulfonamides were synthesized with the aim …