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Articles 2221 - 2250 of 3417

Full-Text Articles in Physical Sciences and Mathematics

Miocene Fluctuations Of The West Antarctic Ice Sheet And The Influence Of Meltwater On The Ross Sea Outer Continental Shelf: Seismic-Stratigraphic Based Interpretations, Sean Francis Kerrin Jan 2010

Miocene Fluctuations Of The West Antarctic Ice Sheet And The Influence Of Meltwater On The Ross Sea Outer Continental Shelf: Seismic-Stratigraphic Based Interpretations, Sean Francis Kerrin

LSU Master's Theses

The changing extents of the West Antarctic Ice Sheet (WAIS) and the manifestation of meltwater discharge on the outer shelf during the Miocene were deduced using seismic stratigraphy and seismic facies interpretations. Deep Sea Drilling Project (DSDP) Leg 28 drill sites were used for chronologic constraints of the outer continental shelf (OCS) seismic stratigraphy to establish correlations to coeval strata at the inner shelf SMS-ANDRIL drill site. The evidence indicates that grounded ice sheets periodically existed on the OCS during the early and middle Miocene and in section inferred to have been deposited in the late-Miocene. Large-scale grounding events occurred …

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Correlation Of Defaults In Complex Portfolios Using Copula Techniques, Adam Lodygowski Jan 2010

Correlation Of Defaults In Complex Portfolios Using Copula Techniques, Adam Lodygowski

LSU Master's Theses

This work, dealing with the correlation between subportfolios in more complex portfolios, begins with a brief survey of the necessary theoretical background. The basic statistical and probabilistic concepts are reviewed. The notion of copulas is introduced along with the fundamental theorem of Sklar. After this background a numerical procedure and code are developed for correlated defaults in multiple correlated portfolio. Further on, interesting results regarding the impact of changes in correlation on the portfolio performance are investigated in the simulations. The most valuable observations regarding the expected default ratios of two subportfolios considered jointly are presented and explained with particular …

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Rapid Microwave-Assisted Acid Extraction Of Chromate Copper Arsenate (Cca)-Treated Southern Pine, Bin Yu Jan 2010

Rapid Microwave-Assisted Acid Extraction Of Chromate Copper Arsenate (Cca)-Treated Southern Pine, Bin Yu

LSU Master's Theses

Recovery of heavy metals from chromated copper arsenate (CCA) treated southern pine wood samples with three different dimension was investigated by recovery with acetic acid, oxalic acid and phosphoric acid in microwave reactor. Diluted phosphoric acid mixed with acetic acid was found to be very effective to remove copper, chromium, and arsenic from spent CCA-treated southern pine sawdust at a high temperature and in a short time. No single acid can totally recover all these three metals in one step in this method. Oxalic acid was effective in removing chromium and arsenic, and acetic acid was effective in removing copper …

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Effective Use Of Web-Based Homework In High School Physics, Elizabeth Pullig Hitt Jan 2010

Effective Use Of Web-Based Homework In High School Physics, Elizabeth Pullig Hitt

LSU Master's Theses

High school physics tests and web-based homework grades were analyzed to determine if web-based homework improves test grades; if the number of web assignments before a test affects the test grade; and if the length of the web assignment affects the number of students that complete the homework assignment. The test grades of students who did their homework were compared to test grades of students who did not do their homework; the assumption was that doing web-based homework improved test grades at this school during the four years studied. The homework group scored seven points higher on average than the …

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Geothermal Resource Assessment Of The Gueydan Salt Dome And The Adjacent Southeast Gueydan Field, Vermilion Parish, Louisiana, Taylor Austin Gray Jan 2010

Geothermal Resource Assessment Of The Gueydan Salt Dome And The Adjacent Southeast Gueydan Field, Vermilion Parish, Louisiana, Taylor Austin Gray

LSU Master's Theses

The fluids heated by the high thermal conductivity and vertical geometry of salt domes in South Louisiana have the potential to be an economic source of geothermal energy. The Gueydan dome is a piercement salt diapir in Southwest Louisiana lying along the Vermilion and Acadia Parish border. Isotherms indicate a thermal anomaly at the crest of the dome with formation temperatures of 62 ˚C recorded at 1346 m, which is too cold for a geothermal prospect. The shallowest salt encountered is at a depth of 1475 m, and the surrounding strata are Cenozoic sand and clay deposits. Previous geothermal assessments …

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Habitat Use, Movements And Spring Migration Chronology And Corridors Of Female Gadwalls That Winter Along The Louisiana Gulf Coast, Jacob M. Gray Jan 2010

Habitat Use, Movements And Spring Migration Chronology And Corridors Of Female Gadwalls That Winter Along The Louisiana Gulf Coast, Jacob M. Gray

LSU Master's Theses

The Louisiana Gulf Coast is an important wintering area for North American gadwall (Anas strepera). Conservation of winter habitat is a top priority of the Gulf Coast Joint Venture. Quantitative estimates of habitat use by wintering gadwall would help improve energetic demand models and subsequent estimates of habitat requirements. I used satellite telemetry (PTTs) to estimate winter habitat and refuge uses, spring migration chronology and corridors, as well as inter- and intra-regional winter movements of females. I used a split-plot MANOVA to evaluate the effects of individual females, female age, winter, hunt periods within winter, time of day, and all …

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A Functional And Ontogenetic Skull Analysis Of The Extant Rhinoceroses And Teleoceras Major, An Extinct Miocene North American Rhinoceros, Mark Daniel Hagge Jan 2010

A Functional And Ontogenetic Skull Analysis Of The Extant Rhinoceroses And Teleoceras Major, An Extinct Miocene North American Rhinoceros, Mark Daniel Hagge

LSU Master's Theses

Functional and ontogenetic skull differences among extant rhinoceroses and the extinct North American rhinoceros Teleoceras major were investigated to assess the unknown feeding ecology of Teleoceras. Ontogenetic skull sequences of the extant Indian rhino (Rhinoceros unicornis), Sumatran rhino (Dicerorhinus sumatrensis), white rhino (Ceratotherium simum), and black rhino (Diceros bicornis), and the extinct Miocene North American rhino T. major were gathered for both qualitative and quantitative assessments. Eleven functional characters related to specific feeding ecologies in extant perissodactyls were morphologically described, and each species’ skull development was described in detail. Nineteen linear skull measurements were taken across all specimens of all …

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Evaluation Of Microfacies Controls On Hydrocarbon Seal Quality, Nchekwube Mbamalu Jan 2010

Evaluation Of Microfacies Controls On Hydrocarbon Seal Quality, Nchekwube Mbamalu

LSU Master's Theses

A microfacies based approach is proposed for the petrophysical prediction of the most effective hydrocarbon seals. Four distinct microfacies types deposited by different deep water depositional processes have been identified based on textural and mineralogical characteristics. Individual microfacies types include: 1) finely laminated, silt poor to slightly silty hemipelagic claystones; 2) faintly laminated, slightly to moderately silty distal hemiturbiditic claystones; 3) weakly laminated, moderately silty to slightly sandy intermediate hemiturbiditic mudstones; and 4) very silty and sandy proximal hemiturbiditic mudstones. Hemipelagic and distal hemiturbiditic claystones (microfacies types 1 and 2) containing well to modestly organized fabric, high total clay contents, …

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Effectiveness Of Forestry Best Management Practices In Minimizing Harvesting Impacts On Streamflow And Sediment Loading In Low-Gradient Headwaters Of The Gulf Coastal Plain, Kristopher Brown Jan 2010

Effectiveness Of Forestry Best Management Practices In Minimizing Harvesting Impacts On Streamflow And Sediment Loading In Low-Gradient Headwaters Of The Gulf Coastal Plain, Kristopher Brown

LSU Master's Theses

Few studies have examined the effectiveness of timber harvesting Best Management Practices (BMPs) in water quality protection of widely-spread, low-gradient, and highly intermittent headwaters on the Gulf Coastal Plain. Also, a spatial disparity exists between the plot-scale water quality benefits afforded by BMP implementation and the watershed-scale with which most watershed stewardship programs are managed. In this thesis research, paired-watershed and Before-After-Control-Impact (BACI) designs were utilized to quantify plot- and watershed-scale changes in streamflow, as well as baseflow and stormflow Total Suspended Sediment (TSS) concentration and yield for 27 months after clearcut harvesting with and without BMPs in a low-gradient, …

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Public Perception Of Wildfire Risk And Prescribed Burning In The Wildland/Urban Interface Of The Louisiana Florida Parishes, Charlotte Ann Gerald Jan 2010

Public Perception Of Wildfire Risk And Prescribed Burning In The Wildland/Urban Interface Of The Louisiana Florida Parishes, Charlotte Ann Gerald

LSU Master's Theses

Wildfire has been suppressed in the nation’s forests for over a hundred years. The accumulation of forest fuels over time has created an urgent need to reduce fuel loads to prevent catastrophic wildfires from occurring, not only in our wildlands, but also in our Wildland/Urban Interfaces (WUI’s). The residents who live within the WUI are particularly vulnerable to extreme wildfire events. As cities become more densely populated, increasing numbers of people are moving beyond the suburbs into the WUI. A complex matrix of structures and forested land, developing communities, and impinging forests exists within the WUI. This study utilized a …

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New Age Control On A Mid-Shelf Grounding Event In Eastern Basin, Ross Sea, Amy Noelle Cone Jan 2010

New Age Control On A Mid-Shelf Grounding Event In Eastern Basin, Ross Sea, Amy Noelle Cone

LSU Master's Theses

It is widely accepted that the West Antarctic Ice Sheet (WAIS) was grounded at the continental shelf edge in Eastern Ross Sea during the Last Glacial Maximum (LGM), but the precise chronology is debated. Existing post-LGM ice retreat chronologies are considered suspect because nearly all have been developed using radiocarbon dating of acid-insoluble organics (AIO). Foraminifer tests yield more accurate radiocarbon dates than AIO because unlike loose sediment, foram tests are unlikely to be contaminated by allochthonous carbon, but unfortunately forams are sparse in Antarctic marine sediment cores. Here I utilized a new 3-D multibeam survey of a mid-continental-shelf grounding …

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The Effects Of Salinity On Nitrogen Cycling In Wetland Soils And Sediments Of The Breton Sound Estuary, La, Brett Whitfield Marks Jan 2010

The Effects Of Salinity On Nitrogen Cycling In Wetland Soils And Sediments Of The Breton Sound Estuary, La, Brett Whitfield Marks

LSU Master's Theses

Wetlands in the coastal zone are slowly becoming more saline under rising sea level over the long-term. However, there are a number of events in the coastal environment which lead to quick and temporary changes in the salinity of coastal marshes. Seawater driven inland from storm surge can significantly increase salinity in oligohaline wetlands over the short-term (weeks). Recent large-scale efforts to restore coastal wetlands in Louisiana have utilized Mississippi River surface water diversions to re-introduce freshwater into coastal marshes, decreasing the salinity of coastal marshes. We examined the effect of salinity changes on two important nitrogen cycling processes, potential …

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Comprehensive Study Of Parameters For Volumetric Modulated Arc Therapy (Vmat) Treatment Planning, Catharine Elizabeth Talbert Jan 2010

Comprehensive Study Of Parameters For Volumetric Modulated Arc Therapy (Vmat) Treatment Planning, Catharine Elizabeth Talbert

LSU Master's Theses

Volumetric modulated arc therapy (VMAT) is a rotational IMRT technique that uses a radiotherapy linear accelerator gantry with a dynamic MLC, variable dose rate, and variable gantry speed. These new degrees of freedom of VMAT delivery introduced complexities for treatment planning, and Pinnacle3 SmartArc treatment module was recently developed as a solution. However, it was unclear how varying each SmartArc parameter affected the resulting plan quality. The purpose of this study was to systematically examine all planning parameters and quantify the effect of varying each on the quality of a reference plan. Parameters were separated into two categories: commissioning parameters …

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Speciation Of Heavy Metals In Disturbed And Undisturbed Sediments From Atchafalaya Bay, Houma Navigation Canal, And Southwest Pass, Louisiana, Amanda Jo Zimmerman Jan 2010

Speciation Of Heavy Metals In Disturbed And Undisturbed Sediments From Atchafalaya Bay, Houma Navigation Canal, And Southwest Pass, Louisiana, Amanda Jo Zimmerman

LSU Master's Theses

In coastal Louisiana it is common to use dredge spoil to build marshland that has been lost due to a variety of factors. Under various conditions such as deposition in a drained oxygenated environment, metals in the spoil can become more bioavailable posing a threat to the ecosystem. This study compares metal availability in natural and dredged sediments to determine what changes occur in nature. Forty four samples from three locations, Atchafalaya Delta, Houma Navigation Canal, and Southwest Pass, were analyzed for 13 common elements with known or potentially harmful health effects; Al, As, Ba, Be, Cd, Cr, Co, Cu, …

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Geological Analysis And Hydrodynamic Modeling Of Tropical Cyclone Influence: Northeastern Gulf Of Mexico Inner Shelf, Amy Lynn Spaziani Jan 2010

Geological Analysis And Hydrodynamic Modeling Of Tropical Cyclone Influence: Northeastern Gulf Of Mexico Inner Shelf, Amy Lynn Spaziani

LSU Master's Theses

The need to characterize offshore resources as borrow areas for beach restoration has initiated interest of the impact of storms to the inner continental shelf. While numerous studies have investigated the response of coastal systems to major storms, very little is known about the geological response of inner shelves to frequent and intense storms. This approach integrated a geological study with modeling of hydrodynamics during recent storms, in order to relate trends in the geological signature to physical forcing mechanisms during storms. First, waves and hydrodynamic conditions were modeled during two major recent storms that made landfall in the northeastern …

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Evaluating Remote Setting Techniques For Oyster (Crassostrea Virginica) Seed Production In Louisiana, Victoria D. Ippolito Jan 2010

Evaluating Remote Setting Techniques For Oyster (Crassostrea Virginica) Seed Production In Louisiana, Victoria D. Ippolito

LSU Master's Theses

Research was conducted to implement remote setting technology for the commercial- scale production of oysters on alternative cultch material in Louisiana. Genetic research has created an enhanced oyster stock for commercial cultivation. Since the Louisiana oyster industry relies on natural seed production for product, they are unable to utilize these new advances and are never guaranteed a reliable source of oyster seed. Remote setting is one way of producing a consistent supply of genetically improved oysters. Cultch material for oyster settlement is a limiting resource. Several alternatives to clamshell have been explored. The objectives of this study are: (1) test …

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Understanding The Use Of Barrier Islands As Nesting Habitat For Louisiana Birds Of Concern, Cecilia Marie Leumas Jan 2010

Understanding The Use Of Barrier Islands As Nesting Habitat For Louisiana Birds Of Concern, Cecilia Marie Leumas

LSU Master's Theses

Colonial nesting seabirds are threatened by habitat loss and degradation, human disturbance, predation, and climate change. Several species of conservation concern concentrate high percentages of their total U.S. populations in Louisiana breeding colonies. We studied seabirds, including Royal Terns, Sandwich Terns, and Black Skimmers, nesting on Isles Dernieres barrier islands along the Gulf coast of Louisiana. Two of the four islands in this chain host extensive seabird colonies and two do not. We used an experimental approach to test the hypothesis that large terns and skimmers are prevented from nesting on Trinity Island, the largest of the Isles Dernieres, by …

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Hepatotoxic Cyanobacterial Blooms In Louisiana's Estuaries: Analysis Of Risk To Blue Crab (Callinectes Sapidus) Following Exposure To Microcystins, Ana Cristina Garcia Jan 2010

Hepatotoxic Cyanobacterial Blooms In Louisiana's Estuaries: Analysis Of Risk To Blue Crab (Callinectes Sapidus) Following Exposure To Microcystins, Ana Cristina Garcia

LSU Master's Theses

The most common toxins detected following freshwater harmful algal blooms are microcystins, a group of hepatotoxins produced by cyanobacteria (e.g., Microcystis and Anabaena spp.). Preference for filter-feeding prey, including bivalves, makes the blue crab, Callinectes sapidus, vulnerable to microcystin contamination and makes the commercially important crab a potential vector of microcystins. I used a combination of field and laboratory studies to determine blue crab vulnerability to microcystin contamination and consequent impacts on crab physiology. Samples collected from a hyper-eutrophic freshwater lake, Lac des Allemands, Louisiana, were analyzed for cyanobacterial abundances and microcystins in surface water and blue crabs using light-microscopy …

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Fraction Competency And Algebra Success, Coretta Thomas Jan 2010

Fraction Competency And Algebra Success, Coretta Thomas

LSU Master's Theses

Abstract In this thesis, I investigated the importance of fraction competence to success in algebra. I studied 107 of the students whom I teach. These students were all enrolled in Algebra I. A fraction pretest and an algebra pretest were given at the beginning of the 2009-2010 school year. A comparison was done to study the connection between the fraction pretest score and the semester grade as well as the algebra pretest score and the semester grade. The strongest correlation was between the fraction pretest and the semester grade. This supported the theory that fraction competence is a strong predictor …

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The Influence Of Two Estrogens On The Sex And Ovarian Development Of Eastern Oysters (Crassostrea Virginica) Maintained In A Closed Recirculating System, Wesley Michael Burnside Jan 2010

The Influence Of Two Estrogens On The Sex And Ovarian Development Of Eastern Oysters (Crassostrea Virginica) Maintained In A Closed Recirculating System, Wesley Michael Burnside

LSU Master's Theses

As a multi-million dollar industry, production of the eastern oyster Crassostrea virginica is significant to the economy of the nation’s coastal regions. The cost of commercial oyster aquaculture has higher inputs than the oyster fishery, but larger, better quality oysters can be produced for culture by the stable availability of triploid individuals.

The goal of this project was to determine if the use of an estrogen, estradiol-17β or estradiol-3-benzoate, at a consistent environmental temperature would increase the percentage of females in a population, as well as ovarian development of eastern oysters. Ultimately, this could be applied to triploids to increase …

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Effective Lesson Planning: Field Trips In The Science Curriculum, Cynthia Rau Rieger Jan 2010

Effective Lesson Planning: Field Trips In The Science Curriculum, Cynthia Rau Rieger

LSU Master's Theses

Science field trips can positively impact students and motivate them into future studies in various science fields. However, if a field trip is not executed properly, it can result in a loss of valuable educational time and could promote misconceptions in the students. This study was undertaken to determine if a classroom lesson before an out-of-the-classroom activity would affect learner gain more or less than a lesson after the activity. The students were divided into two different groups. The groups differed based on the sequence of activities that they received. The activities involved in this study included visiting an immersive …

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Subgroups Of The Torelli Group, Leah R. Childers Jan 2010

Subgroups Of The Torelli Group, Leah R. Childers

LSU Doctoral Dissertations

Let Mod(Sg) be the mapping class group of an orientable surface of genus g, Sg. The action of Mod(Sg) on the homology of Sg induces the well-known symplectic representation:

Mod(Sg) ---> Sp(2g, Z).
The kernel of this representation is called the Torelli group, I(Sg).

We will study two subgroups of I(Sg). First we will look at the subgroup generated by all SIP-maps, SIP(Sg). We will show SIP(Sg) is not I(Sg) and is in fact an infinite index subgroup of I(Sg). We will also classify which SIP-maps are in the kernel of the Johnson homomorphism and Birman-Craggs-Johnson homomorphism.

Then we will …

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Metamorphic Rocks In The Sawtooth Mountains, Idaho, Usa: A Window Into The Precambrian Basement Of Southwest Laurentia, Kyle Michael Metz Jan 2010

Metamorphic Rocks In The Sawtooth Mountains, Idaho, Usa: A Window Into The Precambrian Basement Of Southwest Laurentia, Kyle Michael Metz

LSU Master's Theses

The western North American craton consists of a mosaic of Precambrian basement terranes that developed through episodes of microcontinent collision and magmatic arc accretion. Defining the extent and boundaries of these terranes is critical to deciphering the Precambrian development of Laurentia. The poorly exposed Selway terrane occurs between the Archean Wyoming province and the Neoproterozoic rifted margin of Laurentia. A rare exposure of Precambrian metamorphic rocks, the Sawtooth Metamorphic Complex (SMC), crops out over 33 km2 in the Sawtooth Mountains of Idaho, USA, and potentially provides a window into the deep crust of the region. Field mapping, petrographic analyses, and …

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A Characterization Of Near Outer-Planar Graphs, Tanya Allen Lueder Jan 2010

A Characterization Of Near Outer-Planar Graphs, Tanya Allen Lueder

LSU Master's Theses

This thesis focuses on graphs containing an edge whose removal results in an outer-planar graph. We present partial results towards the larger goal of describing the class of all such graphs in terms of a finite list of excluded graphs. Specifically, we give a complete description of those members of this list that are not 2-connected or do not contain a subdivision of a three-spoke wheel. We also show that no members of the list contain a five-spoke wheel.

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Effects Of Habitat Structural Complexity On Nekton Assemblages: Lab And Field Observations In Southern Louisiana, Austin T. Humphries Jan 2010

Effects Of Habitat Structural Complexity On Nekton Assemblages: Lab And Field Observations In Southern Louisiana, Austin T. Humphries

LSU Master's Theses

Greater structural complexity is often associated with more diverse and abundant species assemblages. Biogenic reefs formed by the eastern oyster (Crassostrea virginica) are structurally complex in nature and have been recognized for their potential habitat value in estuarine systems along the Atlantic and Gulf of Mexico coasts. To determine how the structural complexity of newly created oyster reefs may influence the abundance and distribution of species, three objectives were established. First, to examine spatial and temporal patterns of nekton use at newly created oyster reefs, as well as the impact of wave exposure, six paired oyster reef and mud-bottom treatments …

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Introgression, Health, And Condition Of Florida, Northern, And Fx Hybrid Largemouth Bass In Louisiana Water Bodies, Melissa Ann Fries Jan 2010

Introgression, Health, And Condition Of Florida, Northern, And Fx Hybrid Largemouth Bass In Louisiana Water Bodies, Melissa Ann Fries

LSU Master's Theses

Since 1982, the Louisiana Department of Wildlife and Fisheries (LDWF) has stocked Florida-strain largemouth bass (FLMB; Micropterus salmoides floridanus) to incorporate Florida alleles into native populations (NLMB; M. s. salmoides) and enhance recreational fishing opportunities. I collected habitat data and largemouth bass samples from 12 LDWF stocked reservoirs and disconnected oxbow lakes to examine the relationships between reservoir characteristics, genetic identity, relative weight (Wr), liver somatic index (LSI), parasite loads, and back-calculated length-at-age. I examined the relationships between water body and genetic identity with Wr, LSI, and back-calculated length-at-age by ANOVA. Parasite loads were analyzed with ordinal regression. Principle component …

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Age Related Productivity And Consistency Of Nest Initiation Timing Of Wild Mallards In Eastern North Dakota, Timothy Charles Kimmel Jan 2010

Age Related Productivity And Consistency Of Nest Initiation Timing Of Wild Mallards In Eastern North Dakota, Timothy Charles Kimmel

LSU Master's Theses

Mallards Anas platyrhnchos are arguably the most researched waterfowl species in North America. They exhibit great flexibility in certain breeding metrics such as timing of nest initiation and clutch size. A study on captive female Mallards (Batt and Prince 1979) fed ad libitum, held in identical breeding compartments, and paired with the same mate in each year of the study exhibited substantial variation in the timing of nest initiation within a given year, yet some individual females demonstrated consistency in initiation date among years. My objective was to examine breeding metrics such as timing of nest initiation and clutch size …

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Investigating The Effectiveness Of Informal Science Education Through Quantitative And Qualitative Analysis: Ocean Commotion, Catherine Angela Sutera Jan 2010

Investigating The Effectiveness Of Informal Science Education Through Quantitative And Qualitative Analysis: Ocean Commotion, Catherine Angela Sutera

LSU Master's Theses

Informal science education serves as an important source for science education for both individuals and school groups. However, the effectiveness of school visits to informal science education events outside of either museums or science centers has received little investigation. This study explores the short-term effects of a hands-on learning experience on students’ attitude and content knowledge. Specifically, it investigates the impact of Ocean Commotion, a one-day event where exhibitors present information and hands-on demonstrations about marine environments and products, especially those important to Louisiana. Pre-tests were utilized to document students’ initial knowledge of and attitude toward wetlands and the ocean, …

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Predicting First Year Seedling Survival From Quality Distributions Of Bareroot Seedlings And Microsites, Puskar Nath Khanal Jan 2010

Predicting First Year Seedling Survival From Quality Distributions Of Bareroot Seedlings And Microsites, Puskar Nath Khanal

LSU Master's Theses

Seeding survival has been a continuing problem since the start of the commercial pine plantation in 1950s. The first-year survival of bare-root loblolly pine seedlings at intensively prepared sites in Louisiana has reached a survival plateau of 75 to 85 % with an average of almost 80 %. The major hypothesis of this research was that the survival plateau is a function of the interaction between the frequency distribution of seedling quality and the frequency distribution of microsite quality. This study examined bare-root seedlings and microsite variation, and analyzed the possible options to increase the first-year seedling survival. The study …

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Koszul Duality For Multigraded Algebras, Fareed Hawwa Jan 2010

Koszul Duality For Multigraded Algebras, Fareed Hawwa

LSU Doctoral Dissertations

Classical Koszul duality sets up an adjoint pair of functors establishing an equivalence of categories. The equivalence is between the bounded derived category of complexes of graded modules over a graded algebra and the bounded derived category of complexes of graded modules over the quadratic dual graded algebra. This duality can be extended in many ways. We consider here two extensions: first we wish to allow a multigraded algebra, meaning that the algebra can be graded by any abelian group (not just the integers). Second, we will allow filtered algebras. In fact we are considering filtered quadratic algebras with an …

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