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Articles 1291 - 1320 of 3417

Full-Text Articles in Physical Sciences and Mathematics

Platinum Complexes With Tridentate Ligands As Models For Active Monofunctional Anticancer Drugs, Chase Koby Andrepont Jan 2015

Platinum Complexes With Tridentate Ligands As Models For Active Monofunctional Anticancer Drugs, Chase Koby Andrepont

LSU Doctoral Dissertations

Pt(II) complexes bind preferentially at N7 of G residues of DNA, causing DNA structural distortions associated with anticancer activity. Some distortions induced by difunctional cisplatin are also found for monofunctional Pt(II) complexes with carrier ligands having bulk projecting toward the guanine base. This ligand bulk can be correlated with impeded rotation about the Pt–N7(guanine) bond. The objective of this study is to understand the influences of in-plane bulk of Pt(Ltri)G adducts (Ltri = tridentate carrier ligand, G = guanine derivative bound to a metal, but not tethered to another nucleobase). NMR spectroscopy provided conclusive evidence that Pt(Ltri)G (Ltri = di-(2-picolyl)amine …

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Measuring Social Vulnerability To Environmental Hazards In The Dutch Province Of Zeeland, Ryan Hamilton Kirby Jan 2015

Measuring Social Vulnerability To Environmental Hazards In The Dutch Province Of Zeeland, Ryan Hamilton Kirby

LSU Master's Theses

The Netherlands is a kingdom known for resisting the perils of natural disaster and keeping records of how these great feats were accomplished. The Dutch have measured physical risk through methods such as the intricate VNK models to predict flood scenarios, but little research has been conducted to examine how the people living in affected areas could be impacted from a natural disaster event. This study employs fine-scale data to construct a social vulnerability index for the 164 districts of the low-lying delta province of Zeeland. The methodology used to measure social vulnerability is built on recent social vulnerability and …

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Exploring Rational Numbers In Middle School, Robyn Jasmin Boudoin Jan 2015

Exploring Rational Numbers In Middle School, Robyn Jasmin Boudoin

LSU Master's Theses

The move by the state of Louisiana to fully implement the Common Core State Standards (CCSS) from 2013 -2014 school year on and to align all state mandated tests to the CCSS has caused teachers to change the way they teach and how they deliver content. The overall most crucial new part of the CCSS in Mathematics is the emphasis on the “Standards for Mathematical Practice”. In order to illustrate the meaning of the Mathematical Practice Standards, non routine problems must be used that allow students and teachers to “dig deeper” and practice their mathematical habits of mind. Rational numbers …

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An Analysis Of Risk Perceptions And Attitudes Towards Climate Change Among Residents Of Southeastern Louisiana, Heather Marie Brown Jan 2015

An Analysis Of Risk Perceptions And Attitudes Towards Climate Change Among Residents Of Southeastern Louisiana, Heather Marie Brown

LSU Master's Theses

Climate change is an important issue of concern, as its environmental impacts are already beginning to manifest in various means, such as through sea level rise and increased frequencies of storms. Areas of high vulnerability to the effects of climate change, such as southeastern Louisiana, are prime locations to initiate research in determining what factors influence individual’s risk perceptions towards climate change. This study aims is to identify key factors, specifically in the areas of socioeconomic, demographic, exposure, and attitudinal attributes, which affect climate change risk perceptions. The study area is that of the zip codes around Lake Pontchartrain in …

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Impact Of Exposure To Weathered Crude Oil And Accumulation Of Pahs In Crawfish (Procambarus Clarkii), Brittany Lynn Chichester Jan 2015

Impact Of Exposure To Weathered Crude Oil And Accumulation Of Pahs In Crawfish (Procambarus Clarkii), Brittany Lynn Chichester

LSU Master's Theses

The number of pipelines transporting crude oil and other refined petroleum products across the U.S. has increased 15.4% from 2004 to 2013. In Louisiana, over 3,450 miles of liquid petroleum pipelines crisscross the state. In January 2013, crude oil was accidentally released from an underground pipeline into Bayou Sorrel, Louisiana. This freshwater wetland is located within the Atchafalaya River Basin which is home to large populations of wild crawfish that could be impacted by the crude oil released. This study aims to assess the potential lethal impacts that crude oil spill may have produced in adult crawfish (P. clarkii) and …

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Hybridization And Population Structure Of Western Gulf Coast Mottled Ducks, Robert Joseph Ford Jan 2015

Hybridization And Population Structure Of Western Gulf Coast Mottled Ducks, Robert Joseph Ford

LSU Master's Theses

Rates of hybridization between species that do not normally interbreed have increased due to human impacts on natural environments, such as habitat alteration or introductions of non-native species. Human-induced hybridization can be detrimental to wildlife and contribute to species extinctions. In Florida, feral Mallards (Anas platyrhynchos) hybridize with endemic Mottled Ducks (A. fulvigula) at rates close to 9%. However, levels of hybridization between these two species have not been extensively examined in the western Gulf Coast (from Alabama to northern Mexico) despite the potential impact on the Mottled Duck lineage. In this study, I examined the degree of hybridization between …

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I. Synthesis Of Ascarosides For Biological Evaluation And Ii. Development Of Visible Light-Promoted Selenofunctionalization And Grafting Of Aryl Iodides, Elizabeth Susan Conner Balapitiya Jan 2015

I. Synthesis Of Ascarosides For Biological Evaluation And Ii. Development Of Visible Light-Promoted Selenofunctionalization And Grafting Of Aryl Iodides, Elizabeth Susan Conner Balapitiya

LSU Doctoral Dissertations

This dissertation focuses on analog synthesis for biological evaluation and visible light promoted method development. Chapter 1 centers upon the synthesis of Caenorhabditis elegans dauer pheromone analogs. C. elegans is a nematode which, in times of environmental stress, enters a dauer stage. Two highly conserved pathways, which play important roles in some diseases in higher organisms, monitor dauer formation: TGF-β and IGF-1. Dauer formation is triggered by the nematode’s chemosensation of the dauer pheromone, consisting of a group of previously-isolated ascarosides. These compounds differ in chain length, saturation, terminal functionality of side chain, ω vs. ω-1 oxygenation and presence of …

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Z-Spectral Modeling For Magnetization Transfer Ratio Asymmetry Calculations In Chemical Exchange Saturation Transfer Mri At 3 Tesla, Ryan Nicholas Schurr Jan 2015

Z-Spectral Modeling For Magnetization Transfer Ratio Asymmetry Calculations In Chemical Exchange Saturation Transfer Mri At 3 Tesla, Ryan Nicholas Schurr

LSU Master's Theses

Chemical exchange saturation transfer (CEST) and magnetization transfer (MT) are types of magnetic resonance imaging (MRI) experiments in which contrast is based on the transfer of magnetization from selectively saturated solute or macromolecular protons to bulk water protons. These processes offer insight into the chemical composition of tissue and are quantified by the asymmetry of the magnetization transfer ratio (MTRasym). This study was to develop a Z-spectral curve fitting procedure based on the underlying physics of CEST-MRI from which MTRasym values can be calculated and applied to distinguish healthy tissue from cancer. Z-spectra were collected from CEST-MR images of a …

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Synthesis, Characterization, And Evaluation Of Small Molecule-Based Fluorogenic Probes For The Detection Of Cellular Thiols, Rasika Ranatunga Nawimanage Jan 2015

Synthesis, Characterization, And Evaluation Of Small Molecule-Based Fluorogenic Probes For The Detection Of Cellular Thiols, Rasika Ranatunga Nawimanage

LSU Doctoral Dissertations

Fluorescence methods for disease diagnosis and detection of important analytes are becoming popular route as a technique, as they offer a simple non-invasive approach. Recently, many novel fluorophores and probes have been reported for selectively and sensitively detecting low abundance biological species in disease pathways. Biological thiols, such as glutathione, cysteine, and homocysteine, along with the smallest member hydrogen sulfide, are key thiol analytes in biological environments, and they play a vital role in living systems by maintaining the redox homeostasis of cells. Alteration of their ratios can cause cellular dysfunction and cell death. Furthermore, thiol levels in cells and …

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Analysis Of Nonlinear Dispersive Model Equations, Jacob Grey Jan 2015

Analysis Of Nonlinear Dispersive Model Equations, Jacob Grey

LSU Doctoral Dissertations

In this work we begin with a brief survey of the classical fluid dynamics problem of water waves, and then proceed to derive well known evolution equations via a Hamiltonian Variational approach. This method was first introduced in the seminal work of Walter Craig, et al. \cite{CG}. The distinguishing feature of this scheme is that the Dirichlet-Neumann operator of the fluid domain appears explicitly in the Hamiltonian. In the second and third chapters, we utilize the Hamiltonian perturbation theory introduced in \cite{CG} to derive the Benjamin-Bona-Mahony (BBM) and Benjamin-Bona-Mahony-Kadomtsev-Petviashvili (BBM-KP)equations. Finally, we briefly review the existence theory for their corresponding …

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Augite In Komatiitic Basalts: A Study Of The Mobility Of Trace Elements During Rock Alteration, Alesha C. Morabito Jan 2015

Augite In Komatiitic Basalts: A Study Of The Mobility Of Trace Elements During Rock Alteration, Alesha C. Morabito

LSU Master's Theses

Komatiitic basalts are ultramafic rocks formed from volcanic liquids containing less than 18 wt.% magnesium oxide that can be linked, spatially, geochemically and texturally to komatiites. Archean komatiites and komatiitic basalts are critical to models of early Earth’s mantle evolution. Major and trace elements in these rocks are poorly preserved due to early sub-seafloor alteration with superimposed regional metamorphism: in particular the alkali, alkaline earths, and other elements with low valence numbers. Current analytical methods focus on analyzing whole rock, fresh olivines and melt inclusions to evaluate elemental concentrations and for petrogenetic studies. Although these methods establish elemental concentrations, REE, …

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A Study Of Resiliency In New Orleans Neighborhoods Ten Years After Hurricane Katrina, Paul Ramnauth Algu Jan 2015

A Study Of Resiliency In New Orleans Neighborhoods Ten Years After Hurricane Katrina, Paul Ramnauth Algu

LSU Master's Theses

Hurricane Katrina made landfall on August 29, 2005, flooding over eighty percent of the Greater New Orleans area and causing a mass exodus of the local population. Statistical analysis was used to quantify recovery at a neighborhood level and answer the following questions: What is the recovery rate of New Orleans neighborhoods ten years after Hurricane Katrina? What factors account for variation in recovery rates among neighborhoods? Six neighborhoods in Orleans Parish were selected for further study based on their unique geographical and recovery metrics. Recovery rates among the seventy-two neighborhoods were based on a comparison of United States Postal …

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Magnetic Susceptibility Of North American Ordovician Epicontinental Seas: Spatial Variability And Sandbian-Katian Boundary Correlation, Thomas J. Schramm Jan 2015

Magnetic Susceptibility Of North American Ordovician Epicontinental Seas: Spatial Variability And Sandbian-Katian Boundary Correlation, Thomas J. Schramm

LSU Doctoral Dissertations

Magnetic susceptibility (χ) has gained increased usage as a stratigraphic correlation tool. This project evaluates the utility of a χ correlation tool, including its shortcomings, and attempts its integration with other datasets. The Upper Ordovician of eastern North America represent the stratigraphic interval in which these experiments were conducted. 4566 samples were collected for the purposes of this study, and χ was measured on 3345 of the samples. This project includes three major facets, 1) the spatial variability of χ, 2) correlation of Sandbian-Katian boundary interval strata in eastern North America using χ, and 3) utility of χ for interpreting …

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Sub-Marine Sediment Instability Near Southwest Pass Of The Mississippi River: Evidence Of Mass Movements From Raciochemistry And Other Proxies, Gregory Paul Keller Jan 2015

Sub-Marine Sediment Instability Near Southwest Pass Of The Mississippi River: Evidence Of Mass Movements From Raciochemistry And Other Proxies, Gregory Paul Keller

LSU Master's Theses

Mass wasting events are an important geomorphic control on the Mississippi River Delta Front. Short multicores (<50cm) and longer gravity cores (<3m) were collected seaward of the Southwest Pass of the Mississippi River Delta and were analyzed to assess the frequency, extent, and potential causes of submarine mass wasting events. Cores were analyzed for radionuclide activity, grain size, and density at 2cm resolution. Short-term sedimentation rates calculated from 7-Be are 2-16cm/y, while longer-term accumulation from 210-Pb are only 1.3-7.3 cm/y. In most cores, 210-Pb activity steadily decreases downcore without displaying a “stairstep” nature. However, seven cores have layers of low 210-Pb activity stratigraphically above layers with higher activity. In a gravity core from a mudflow gully, 210-Pb steadily decreases for the upper 70 cm before stabilizing for the remaining 150 cm. Clay content generally ranges between 25-40% and sand ranges between 5-15% with silt making up the rest of each sample. Sediment accumulation rates derived from 210-Pb in the short cores indicate that proximity to the river mouth has stronger influence than depositional environment (mudflow gully, depositional lobe, prodelta). This finding may be explained by rapid sedimentation rates coupled with a reduced tropical cyclone activity over the delta in the last seven years (2006-2013) which is a known cause of mass wasting events. The regions of decreased 210-Pb activity may be evidence of scavenging effects of plume sedimentation because they do not correspond with decreases in clay fraction. The layer of homogenized activity below 70cm in the gully core corresponds with a layer of decreased density. This layer occurs at a depth equivalent to 9-18 years, indicating mixing on a decadal scale from mudflows. These results may be explained by a lack of recent mass failures corresponding with lulls in tropical cyclone activity over the delta, preceded by a period of more active hurricane-driven mudflow activity.

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If You Build It, What Will Come? Assessing The Avian Response To Wetland Restoration In The Mississippi River Bird’S Foot Delta Through Multiple Measures Of Density And Biodiversity, Lauren Rae Sullivan Jan 2015

If You Build It, What Will Come? Assessing The Avian Response To Wetland Restoration In The Mississippi River Bird’S Foot Delta Through Multiple Measures Of Density And Biodiversity, Lauren Rae Sullivan

LSU Master's Theses

Multiple wetland restoration and enhancement techniques are used in Louisiana to combat land loss and provide habitat for waterbirds. We investigated the avian response to three wetland restoration techniques in the Lower Mississippi Bird’s Foot Delta to determine if the different habitat types resulted in differences in the value of edge habitat. Species richness, guild richness, total bird density, bird density by foraging guild, and bird abundance relative to distance from the marsh edge was compared among (i) crevasse splays, a type of sediment diversion which allow the river to build new wetlands, (ii), beneficial use of dredged material marshes, …

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Large-Scale Geometric Data Decomposition, Processing And Structured Mesh Generation, Wuyi Yu Jan 2015

Large-Scale Geometric Data Decomposition, Processing And Structured Mesh Generation, Wuyi Yu

LSU Doctoral Dissertations

Mesh generation is a fundamental and critical problem in geometric data modeling and processing. In most scientific and engineering tasks that involve numerical computations and simulations on 2D/3D regions or on curved geometric objects, discretizing or approximating the geometric data using a polygonal or polyhedral meshes is always the first step of the procedure. The quality of this tessellation often dictates the subsequent computation accuracy, efficiency, and numerical stability. When compared with unstructured meshes, the structured meshes are favored in many scientific/engineering tasks due to their good properties. However, generating high-quality structured mesh remains challenging, especially for complex or large-scale …

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Knots, Skein Theory And Q-Series, Mustafa Hajij Jan 2015

Knots, Skein Theory And Q-Series, Mustafa Hajij

LSU Doctoral Dissertations

The tail of a sequence {P_n(q)} of formal power series in Z[q^{-1}][[q]], if it exists, is the formal power series whose first $n$ coefficients agree up to a common sign with the first n coefficients of P_n. The colored Jones polynomial is link invariant that associates to every link in S^3 a sequence of Laurent polynomials. In the first part of this work we study the tail of the unreduced colored Jones polynomial of alternating links using the colored Kauffman skein relation. This gives a natural extension of a result by Kauffman, Murasugi, and Thistlethwaite regarding the highest and lowest …

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Factors Influencing Mottled Duck Nest Success On The Atchafalaya River Delta, Brendan Caillouet Jan 2015

Factors Influencing Mottled Duck Nest Success On The Atchafalaya River Delta, Brendan Caillouet

LSU Master's Theses

The Atchafalaya River Delta system along with the Wax Lake Outlet Delta and the Mississippi River Delta are the only three areas in Louisiana where land is being gained. Beneficial use of dredge spoil from shipping channel maintenance is used on the Atchafalaya River Delta to supplement natural accretion. These dredge spoil islands have the ability to provide valuable nesting habitat for a variety of waterbirds, including Mottled Ducks. Previous studies on these islands reported mammalian predation to be a significant cause of nest failure for Mottled Ducks. I tested the hypothesis that predator reduction through trapping would increase Mottled …

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An Ion Detector For The Array For Nuclear Astrophysics And Structure With Exotic Nuclei (Anasen), Cedric Williams, K Macon, C M. Deibel, J C. Blackmon Jan 2015

An Ion Detector For The Array For Nuclear Astrophysics And Structure With Exotic Nuclei (Anasen), Cedric Williams, K Macon, C M. Deibel, J C. Blackmon

Honors Theses

No abstract provided.

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Expression And Characterization Of Mouse Notch1 Abruptex Egf Repeats In E. Coli, Amid Paudyal Jan 2015

Expression And Characterization Of Mouse Notch1 Abruptex Egf Repeats In E. Coli, Amid Paudyal

LSU Master's Theses

Notch1 is a transmembrane protein involved in cell signaling, which is found to be linked to various genetic and neurodegenerative diseases. The extracellular domain of the Notch1 protein consists of 36 tandem epidermal growth factor-like (EGF) repeats, which are directly involved in ligand binding and are heavily glycosylated. EGF 24-29 repeats lie in the Abruptex region of the Notch1 protein, and regulate the ligand binding activity through structural changes. The role of glycosylation in ligand binding events and the overall structure of the Abruptex region are not known. Also, the role of calcium binding in Notch activation or inhibition is …

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Effects Of Hydrologic Modifications On Flooding In Bottomland Hardwoods, Erin Johnson Jan 2015

Effects Of Hydrologic Modifications On Flooding In Bottomland Hardwoods, Erin Johnson

LSU Master's Theses

Complex fluvial processes influence floodplains. River modifications in the 1930s have affected hydrogeomorphic processes influencing the lower White River in southeastern Arkansas. The overall objective of this study was to better understand the hydrologic and geomorphic influence on the floodplain forest. We used the HEC-RAS model to quantify hydrologic relationships within the floodplain before and after 1930s river modifications. The model can replicate flooding within 3-5 m. Despite river modifications, HEC-RAS modeling showed headwater floods influenced the upper reach of the floodplain while backwater floods from the Mississippi River influenced the lower reach of the floodplain. Post-1930s incision that occurred …

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The Effects Of Tropical Storms And Hurricanes On Phytoplankton And Nutrient Concentrations In Wetland-Estuary Transition Zones Along The Gulf Coast, Tiffany Chantelle Johnson Jan 2015

The Effects Of Tropical Storms And Hurricanes On Phytoplankton And Nutrient Concentrations In Wetland-Estuary Transition Zones Along The Gulf Coast, Tiffany Chantelle Johnson

LSU Master's Theses

Two consecutive storms made landfall along the Northern Gulf of Mexico on June and August 2012 (Tropical Storm Debby, 06/26/2012; Isaac, 08/28/2012, Category (Cat) 1 Saffir-Simpson Hurricane Scale). Each storm passed within 48 to 273 km of one of seven wetland-estuary transition zone sampling sites, and indirect storm effects associated with changes in freshwater discharge and an inflow of inorganic nutrients were observed at five of the seven sites. To assess the impacts of the 2012 hurricanes on hydrology, nutrient concentrations, and phytoplankton concentrations at transition zones along the Gulf Coast, a within-sites analysis along with a seasonal analysis were …

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Bridging Gaps: Supplemental Materials For Struggling Students In Common Core Aligned Algebra 1, Reynalin Apinardo Baricuatro Jan 2015

Bridging Gaps: Supplemental Materials For Struggling Students In Common Core Aligned Algebra 1, Reynalin Apinardo Baricuatro

LSU Master's Theses

This thesis emphasizes the need for, and the development of, auxiliary and supplemental materials for students struggling with the Module 1 of the Common Core aligned EngageNY/Eureka Math, Algebra 1 Curriculum, in particular, special education students and regular education students who are missing essential pre-requisite skills. The goal of this thesis is to provide resources which assist both the students and the teachers with the transition from the old Louisiana Comprehensive Curriculum to the intensity, rigor, and mathematical sophistication of the new Common Core aligned curriculum. Clearly, the need for supplementary materials is not restricted to the first of six …

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Effects Of Oil Spill And Recovery Of Terrestrial Arthropods In Louisiana Saltmarsh Ecosystem, Wokil Bam Jan 2015

Effects Of Oil Spill And Recovery Of Terrestrial Arthropods In Louisiana Saltmarsh Ecosystem, Wokil Bam

LSU Master's Theses

Saltmarshes are under continuous multiple stressors such as, land loss, erosion, climate change, environmental pollutions and oil spills, which affect the ecological communities inhabiting saltmarshes. Terrestrial arthropods play an important role in the ecology of saltmarshes, affecting primary production and decomposition. Arthropods are often found in the gut contents of Seaside Sparrows and fishes making them an important trophic link to terrestrial and marine vertebrates. Insects and spiders have the potential to be a good indicator of overall marsh health and environment as they are differentially sensitive to oil exposure. Oil pollutants may have significant long-term negative impacts on the …

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An Accelerated Middle School Mathematics Curriculum: Combined Engageny Math 6 And Math 7 Curriculum, Emily Jane Moran Jan 2015

An Accelerated Middle School Mathematics Curriculum: Combined Engageny Math 6 And Math 7 Curriculum, Emily Jane Moran

LSU Master's Theses

This thesis discusses the importance and benefits of subject acceleration for mathematically gifted students. The objective was to create an accelerated mathematics curriculum for mathematically gifted students by combining the Math 6 and Math 7 EngageNY curricula and adapting these curricula to meet the needs of my gifted students. This curriculum is to be implemented in a gifted classroom, which allows students to be on an accelerated path in mathematics. This thesis focuses on the Accelerated Mathematics 6 program implemented for 15 sixth grade gifted and scholastic academy students at Woodlawn Middle School, a school located in Baton Rouge, Louisiana. …

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Increasing Student Engagement In The Secondary Math Classroom, Chantell Holloway Walker Jan 2015

Increasing Student Engagement In The Secondary Math Classroom, Chantell Holloway Walker

LSU Master's Theses

This thesis reports on a professional development package developed by the author to help three teachers increase the level of student engagement in their math classrooms. There were three phases: 1) initial presentation of strategies and sample lessons, 2) classroom implementation, 3) reflection and evaluation. As a result of the professional development, the Louisiana Compass Teacher Evaluation Rubric scores of the teachers improved in the area of student engagement. This thesis can be used as a guide for principals or instructional specialists who wish to provide professional development for small groups of teachers, with a focus on increasing student engagement.

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Analyzing Site Suitability For Baldcypress (Taxodium Distichum) Regeneration Along A Hydrologic Gradient In South Louisiana Swamps, Marcus Rutherford Jan 2015

Analyzing Site Suitability For Baldcypress (Taxodium Distichum) Regeneration Along A Hydrologic Gradient In South Louisiana Swamps, Marcus Rutherford

LSU Master's Theses

The future of Louisiana’s coastal cypress-tupelo forests is threatened by prolonged or permanent flooding during the growing season. Permanent inundation prevents baldcypress seedlings from becoming established. The upper limit of submergence with respect to adequate planted baldcypress seedling performance has not been effectively tested under actual field conditions. Similarly, an effective method for determining a site’s regeneration potential based on present vegetation attributes has not been developed. To test first-year performance of planted baldcypress seedlings under varying levels of submergence, I planted 900 of both 1-0 and 2-0 age-class bare-root seedlings across 12 different sites covering a range of hydrologic …

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Constructing Desirable Scalar Fields For Morse Analysis On Meshes, Mustafa Hajij Jan 2015

Constructing Desirable Scalar Fields For Morse Analysis On Meshes, Mustafa Hajij

LSU Master's Theses

Morse theory is a powerful mathematical tool that uses the local differential properties of a manifold to make conclusions about global topological aspects of the manifold. Morse theory has been proven to be a very useful tool in computer graphics, geometric data processing and understanding. This work is divided into two parts. The first part is concerned with constructing geometry and symmetry aware scalar functions on a triangulated $2$-manifold. To effectively apply Morse theory to discrete manifolds, one needs to design scalar functions on them with certain properties such as respecting the symmetry and the geometry of the surface and …

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Microtopographic Ecohydrology Of A Forested Wetland In Louisiana, Yu-Hsin Hsueh Jan 2015

Microtopographic Ecohydrology Of A Forested Wetland In Louisiana, Yu-Hsin Hsueh

LSU Master's Theses

Coastal wetland forest ecosystems rely on the intimate interactions of hydrology, salinity, and coastal forest vegetation. The boundary between marsh and forest is often where hummock-swale terrain exists. It remains unknown as to the degree to which trees may experience varied salinity level within hummocks provided with freshwater flux. This study examined the hydrological regime of the hummock-swale terrain that resulted in salinity variation and whether freshwater source exists for baldcypress. Natural tracers of stable isotopes of water and salinity were applied to understand the sources of water. To better examine the tracers used, we conducted several experiments to gain …

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Rare Earth Element Patterns In Conodont Apatite From The Upper Ordovician: Testing Enrichment Sources And Possible Oceanographic Changes, Cody Christian Schulte Jan 2015

Rare Earth Element Patterns In Conodont Apatite From The Upper Ordovician: Testing Enrichment Sources And Possible Oceanographic Changes, Cody Christian Schulte

LSU Master's Theses

The Mohawkian series of the Middle Late Ordovician was a time of great lithological and faunal changes that coincide with a positive ä13C excursion known as the Guttenberg Isotopic Carbon Excursion (GICE). Two prevailing hypotheses have been proposed to explain the cause of these changes. The “cold-water” hypothesis suggests that global cooling caused the tropical belt to shrink and cold water to invade the epicontinental sea while the “tectonic-forcing” hypothesis suggests that increased weathering rates led to basinal deepening, resulting in cooler oceanic waters invading the midcontinent sea. This study tests if regional tectonics caused by the Taconic Orogeny led …

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