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Articles 2641 - 2670 of 3417

Full-Text Articles in Physical Sciences and Mathematics

Evolution Of An Allochthonous Salt System, Southern Mars-Ursa Basin, Northern Gulf Of Mexico, Angela Bordelon Pell Jan 2007

Evolution Of An Allochthonous Salt System, Southern Mars-Ursa Basin, Northern Gulf Of Mexico, Angela Bordelon Pell

LSU Master's Theses

This study examines the evolution of an allochthonous salt system in the southern Mars-Ursa basin. A seismic stratigraphic framework and biostratigraphic markers provided constraints on basin development and sediment accumulation from late Miocene to middle Pliocene time. External geometries of tectonostratigraphic packages are identified in the study area and are combined with analyses of brittle deformation to track salt evacuation in the study area. External geometries identified in the study include: wedge, layer and trough. Fifty-nine faults were mapped in basin and suprasalt strata and five phases of brittle deformation were identified. Eight evolutionary stages were identified for the time …

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Environmental Factors Influencing The Siting Of Temporary Housing In Orleans Parish, Philip J. Chandler Jan 2007

Environmental Factors Influencing The Siting Of Temporary Housing In Orleans Parish, Philip J. Chandler

LSU Master's Theses

The disaster in New Orleans due to Hurricane Katrina showcased the city's many environmental problems. The industrial history of the city, subsidence of the city causing it to be below sea-level, and the fact that the city is protected by levees and pumps were critical elements of the disaster and played a large role in the emergency response. The disaster led to an enormous emergency response by many entities, but the Federal Emergency Management Agency (FEMA) has the lead in these actions. In response to the large number of homes being flooded and unlivable in Orleans Parish, FEMA implemented its …

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Evaluation Of Harvesting Disturbance And Establishment Practices On Early Height Growth Of Loblolly Pine (Pinus Taeda L.), Shanna Marie Mccarty Jan 2007

Evaluation Of Harvesting Disturbance And Establishment Practices On Early Height Growth Of Loblolly Pine (Pinus Taeda L.), Shanna Marie Mccarty

LSU Master's Theses

Land for forest plantations is declining while demand for forest products is increasing, creating concern over sustainable forest management. Maintenance of site productivity is fundamental to forest sustainability, and an assessment of cumulative height growth is a useful index of productivity. Loblolly pine height data were used from four research plantations installed by the project Cooperative Research in Sustainable Silviculture and Soil Productivity from Texas to Georgia. The sites vary in soil characteristics, management history, nutrient status at time of planting, and age (from 4 to 9 years). Each site is a randomized complete block design with a factorial treatment …

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Hurricane Modeling In Gis: An Investigation Of Threshold Storm Events Affecting Special Medical Needs Populations In Coastal Louisiana, Kathryn Emily Streva Jan 2007

Hurricane Modeling In Gis: An Investigation Of Threshold Storm Events Affecting Special Medical Needs Populations In Coastal Louisiana, Kathryn Emily Streva

LSU Master's Theses

Recent hurricane events in coastal Louisiana have emphasized the severe vulnerability of medical special needs (MSN) patients during flood disasters. MSN populations may be comprised of hospital, nursing home or hospice patients; the physically or mentally disabled; medically-dependent individuals requiring life-sustaining equipment or medicines; and frail elderly. Over 150 hospital and nursing home fatalities resulted from Hurricane Katrina in New Orleans. More than four hundred elderly over the age of seventy perished. Chronic diseases and mental health illness were among the top conditions reported in field hospitals, emergency rooms and shelters immediately following the storm. Louisiana MSN facilities and residences …

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Synthesis And Properties Of Isoporphyrins And Related Derivatives For Application In Photodynamic Therapy, Sandra Celinah Mwakwari Jan 2007

Synthesis And Properties Of Isoporphyrins And Related Derivatives For Application In Photodynamic Therapy, Sandra Celinah Mwakwari

LSU Doctoral Dissertations

Isoporphyrins are tautomers of porphyrins with an interrupted macrocyclic conjugation owing to the presence of a sp3 hybridized meso-carbon. Due to their absorption at long wavelengths (~800nm), isoporphyrins are potential candidates as photosensitizers in photodynamic therapy (PDT), a ternary modality of cancer treatment. They are also of biological interest due to their unique redox properties among porphyrin derivatives and could be a new class of near-IR dyes. Isoporphyrins are known to be unstable with respect to transformation back to the fully conjugated porphyrin chromophore except when the meso-carbon is geminally substituted and for this reason a detailed study of this …

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Predicting Water Quality Effects On Bay Anchovy (Anchoa Mitchilli) Growth And Production In Chesapeake Bay: Linking Water Quality And Individual-Based Fish Models, Aaron Thomas Adamack Jan 2007

Predicting Water Quality Effects On Bay Anchovy (Anchoa Mitchilli) Growth And Production In Chesapeake Bay: Linking Water Quality And Individual-Based Fish Models, Aaron Thomas Adamack

LSU Doctoral Dissertations

Water quality in the Chesapeake Bay and the Patuxent River has decreased since the 1950s due to an increase in nutrient loadings. Increased nutrient loads have caused an increase in the extent and duration of hypoxic conditions. Restoration via large-scale reductions in nutrient loadings is now underway. How reducing nutrient loadings will affect water quality is well predicted; however the effect on fish is generally unknown as most water quality models do not include trophic levels higher than zooplankton. I combined two water quality models with bay anchovy models (Anchoa mitchilli) to examine the effects of changes in nutrient loadings …

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Multifunctional Ligands For Supramolecular Chemistry, James Kakoullis Jan 2007

Multifunctional Ligands For Supramolecular Chemistry, James Kakoullis

LSU Master's Theses

Metal-organic frameworks (MOFs) are the primary focus of the Maverick research group, almost exclusively with the acac moeity. Before such MOFs can be attempted, multifunctional ligands of the appropriate geometry for the desired MOFs first must be synthesized. In this thesis, the synthesis and characterization of two new β-diketone ligands, specifically, Re(CO)3Cl(PyacH)2, 2.2, Pphac3H3, 1.23, and its oxide 3.6, are described. Also in this thesis, attempts to synthesize other new MOFs will be discussed. The MOF for which Re(CO)3Cl(PyacH)2, 2.2 was designed was Re(CO)3ClCu(pyac)2] …

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Chemical Analysis Of Extracts From Port-Orford Cedar Wood And Bark, Heng Gao Jan 2007

Chemical Analysis Of Extracts From Port-Orford Cedar Wood And Bark, Heng Gao

LSU Master's Theses

This study investigated a Soxhlet extract procedure to separate chemical components in the wood and bark of Port-Orford cedar (POC) (Chamaecyparis lawsoniana). The bio-activities, antioxidant properties, and decay resistance were evaluated. The heartwood extracts were analyzed by gas chromatography-mass spectrometry (GC-MS). Three vitro assays including (1) 1, 1-diphenyl-2-picrylhydrazyl hydrate (DPPH• ) radical scavenging assay, (2) 2,2-azinobis ( 3-ethylbenzothiszoline-6-sulfonic acid) diammonium salt (ABTS) radical cation scavenging ability assay, and (3) metal chelating activity assay were carried out to evaluate the antioxidant activity. The total phenol content of the extracts was determined by the Folin-Ciocalteu method and expressed as Gallic Acid Equivalent …

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Evaluation Of Anuran Richness In Restored Wetlands Of Central Louisiana, Sarah Jane Barlow Jan 2007

Evaluation Of Anuran Richness In Restored Wetlands Of Central Louisiana, Sarah Jane Barlow

LSU Master's Theses

Bottomland hardwood forests and associated fauna, including frogs, are disappearing. The 1990 Farm Bill created a wetland restoration program on private lands called the Wetland Reserve Program (WRP) that has the potential to reverse the declines in species associated with bottomland hardwood forests. As of September 2005, nearly 85,000 ha had been enrolled in Louisiana, but the structure and value of these wetlands to frogs is not known. I evaluated 22 restored and 8 reference wetlands from January through May in 2004 and 2005 to determine the effects of local and landscape scale habitat characteristics on frog species richness and …

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Evaluation Of Mvct Images With Skin Collimation For Electron Treatment Planning, Allen Beardmore Jan 2007

Evaluation Of Mvct Images With Skin Collimation For Electron Treatment Planning, Allen Beardmore

LSU Master's Theses

Purpose: To evaluate the accuracy of electron beam dose calculations in MVCT images containing lead alloy masks. Method and Materials: A phantom consisting of two 30x30x5 cm3 slabs of CIRS plastic water® was imaged using kVCT (GE Lightspeed-RT) and MVCT (TomoTherapy Hi·Art). Nine MVCT scans were taken with different square masks of lead alloy (Cerrobend®, density = 9.4 g·cm-3) on top of the phantom. The masks contained square apertures of 3x3 cm2, 6x6 cm2 and 10x10 cm2 and had thicknesses of 6 mm, 8 mm and 10 mm. The same collimation was simulated …

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Relationships Between Macroinvertebrate Communities And Environmental Characteristics Of Headwater Streams In Central Louisiana, Adrienne Viosca Jan 2007

Relationships Between Macroinvertebrate Communities And Environmental Characteristics Of Headwater Streams In Central Louisiana, Adrienne Viosca

LSU Master's Theses

Headwater streams are an integral part of any watershed system because they strongly influence the physical, chemical, and biological components of downstream reaches. Little information exists about macroinvertebrate community structure, spatiotemporal variation, or their relationships with environmental factors in low-gradient headwater streams of the subtropical coastal plain region in the Southern US. These headwater streams are typically slow moving, capable of accumulating large amounts of organic material, and often become intermittent during the dry season. Research is needed to understand the effects of these unique characteristics on stream health and ecology. This study aimed to determine aquatic macroinvertebrate community structure, …

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Early Flotant Establishment And Growth Dynamics In A Nutrient Amended Wetland In The Lower Mississippi River Delta, Caleb W. Izdepski Jan 2007

Early Flotant Establishment And Growth Dynamics In A Nutrient Amended Wetland In The Lower Mississippi River Delta, Caleb W. Izdepski

LSU Master's Theses

Nutrient dynamics and seasonal marsh growth were examined in a newly formed Panicum virgatum floating marsh at Thibodaux LA. The floating marsh formed in a cleared area of forested wetland receiving secondarily treated effluent. Net Areal Primary Productivity (NAPP), total belowground biomass, NO3, and δ15N ratios varied significantly (P <0.05) along a 75m marsh transect while mean δ13C varied between plant species. The upland end of the transect had the highest NAPP (3876 g m-2y-1), total belowground biomass (4079.0 ± 298.5 g m-2), and mean NO3 (5.4 ± 2.9 mg l-1). The mean floating-marsh …

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Quantifying The Edge Effects Associated With Predator Removal Blocks On The Nesting Success Of Upland Ducks In North Dakota, Margaret Jean Kuhn Jan 2007

Quantifying The Edge Effects Associated With Predator Removal Blocks On The Nesting Success Of Upland Ducks In North Dakota, Margaret Jean Kuhn

LSU Master's Theses

Much evidence suggests that nest success is one of the key drivers of duck production. Accordingly, for the past thirty years, waterfowl managers have focused their efforts on increasing nest success. One way to increase nest success is through predator trapping. Previous studies have shown that predator trapping increases nest success on different sized trapped blocks. This study attempted to answer the question: does trapping affect nest success on areas directly adjacent to trapped block boundaries? I hypothesized that predator abundance outside trapped blocks would be reduced. I predicted that nest success would decline with distance from the boundary while …

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Evaluation Of Allochthonous And Autochthonous Microbial Populations In The In-Situ Remediation Of Weathered Oil In A Coastal Freshwater Habitat, Kyle Alan Schmidt Jan 2007

Evaluation Of Allochthonous And Autochthonous Microbial Populations In The In-Situ Remediation Of Weathered Oil In A Coastal Freshwater Habitat, Kyle Alan Schmidt

LSU Master's Theses

Use of bioremedial technologies has gained popularity in recent decades for application at oil spill sites. While much research has been done on specific case studies along marine shores, such as with the spill of the Exxon Valdez, there still remain questions as to the advantage of active biological treatment vs. natural attenuation in freshwater environments. To examine this question, a comparative study of allochthonous and autochthonous microbial communities ability to degrade weathered oil residuals was implemented at the CITGO Petroleum Refinery in Lake Charles, Louisiana following a spill of approximately 40,000 barrels of slop oil on June 19th, 2006 …

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Habitat Use, Movements, And Survival Of Radio-Marked Female Mallards In The Lower Mississippi Alluvial Valley, Bruce Edward Davis Jan 2007

Habitat Use, Movements, And Survival Of Radio-Marked Female Mallards In The Lower Mississippi Alluvial Valley, Bruce Edward Davis

LSU Master's Theses

Mallard (Anas platyrhynhcos) populations in the Lower Mississippi Alluvial Valley (LMAV) historically averaged 1.6 million and represented the largest concentrations of wintering mallards in North America. Effective management of this wintering population requires current information on use of habitats, movements, and survival of female mallards. I used radio-telemetry techniques to assess these parameters during winters 2004-2005 and 2005-2006. Radio-marked female mallards used forested wetland habitats extensively during diurnal and nocturnal sampling periods. Proportional use of habitats varied inconsistently among time periods defined by hunting seasons and winters. Proportional use of forested wetlands ranged from 0.464 to 0.816 and from 0.280 …

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Reducing False Alarms In Searches For Gravitational Waves From Coalescing Binary Systems, Andres Rodri­Guez Jan 2007

Reducing False Alarms In Searches For Gravitational Waves From Coalescing Binary Systems, Andres Rodri­Guez

LSU Master's Theses

LIGO observatories in Livingston, LA and Hanford, WA may detect gravitational waves emitted from coalescing binary systems composed of two compact objects. In order to detect compact binary coalescence (CBC) events, LIGO searches utilize matched filtering techniques. Matched filtering is the optimal detection strategy for stationary, Gaussian noise, however, LIGO noise is often non-stationary, non-Gaussian. Non-stationary noise result in an excess of false candidate events, commonly known as false alarms. This thesis develops the r2 test to reduce the false alarm rate for LIGO CBC searches. Results of the search for primordial black hole binary systems (where each object …

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Evaluation Of Compliance With The Long Term 1 Enhanced Surface Water Treatment Rule, Racquel Rena Douglas Jan 2007

Evaluation Of Compliance With The Long Term 1 Enhanced Surface Water Treatment Rule, Racquel Rena Douglas

LSU Master's Theses

Cryptosporidium is a common protozoan parasite that causes cryptosporidiosis, a severe gastrointestinal disease. Currently, there is no antibiotic available to treat the disease. Cryptosporidium has been responsible for several waterborne disease outbreaks in the United States. The largest cryptosporidiosis outbreak in United States history occurred in Milwaukee, Wisconsin in spring 1993. The vulnerability of the United State drinking water supply to waterborne disease outbreak is still prevalent nearly 15 years after the Milwaukee outbreak. In order to effectively control Cryptosporidium, the EPA has strengthened the regulations on turbidity control for filtration performance by implementing the Long Term 1 Enhanced Surface …

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Use Of An Agricultural Non-Point Source Pollution Model To Assess Impacts Of Development And Management Practicies [Sic] In An Urban Watershed, John Admiral Cross Jan 2007

Use Of An Agricultural Non-Point Source Pollution Model To Assess Impacts Of Development And Management Practicies [Sic] In An Urban Watershed, John Admiral Cross

LSU Master's Theses

A Geographical Information System (GIS) linked to a Non-Point Source (NPS) model are being used to predict the effectiveness of storm water management strategies and examine the impact of proposed land use changes on Total Maximum Daily Load (TMDL) attainment. This study tests a methodology for analyzing land use changes and management using GIS analyses of impervious surfaces and AGricultural Non-Point Source (AGNPS) pollution modeling in an approximate 1100 acre urban watershed located in East Baton Rouge Parish (EBRP), Louisiana. The GIS analyses of Total Impervious Area (TIA) quantified increases in urbanization and provided land use data utilized in AGNPS …

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Accuracy Of Cranial Coplanar Beam Therapy With Brainlab Exactrac Image Guidance, Justin Vinci Jan 2007

Accuracy Of Cranial Coplanar Beam Therapy With Brainlab Exactrac Image Guidance, Justin Vinci

LSU Master's Theses

Purpose: To develop a system for measuring 2D dose distributions in the cranium and to use this system to evaluate the accuracy of coplanar conformal therapy using ExacTrac image guidance. Methods: Techniques were developed to measure dose distributions in each principal plane using a CIRS anthropomorphic head phantom with a custom internal film cassette. Sections of EDR2 film were cut, processed, and digitized using custom templates. Spatial and dosimetric accuracy and precision of the film system was assessed. BrainScan was used to plan a coplanar-beam treatment conforming to irradiate a 2-cm diameter x 2-cm cylindrical target. Prior to delivery phantom …

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Laboratory Evaluation Of Dunaliella Tertiolecta As A Candidate Algal Species For Tertiary Wastewater Treatment Of Nitrogen And Phosphorus-Laden Effluents Impacting Marine Environments, Ashley Juanika Belle Jan 2007

Laboratory Evaluation Of Dunaliella Tertiolecta As A Candidate Algal Species For Tertiary Wastewater Treatment Of Nitrogen And Phosphorus-Laden Effluents Impacting Marine Environments, Ashley Juanika Belle

LSU Master's Theses

Dunaliella tertiolecta was evaluated to determine the effectiveness of utilizing the algal species to reduce the nutrient load of saline wastewater during tertiary treatment. Nutrient uptake studies performed using f/2-Si medium illustrated that Dunaliella tertiolecta favored phosphate uptake over nitrate-nitrogen. Over a 7-day observational period, total phosphorus concentration was reduced by over 97% and the kinetic rate of uptake observed was approximately 0.5 - 1 mg/L/day. Daily nitrate-nitrogen concentrations were highly variable and a model could not be determined to predict uptake behavior. In heavily concentrated nutrient loads, the algae still favored phosphate uptake. However as the nutrient load increased …

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Providing The Best Of Both Worlds: Balancing Conservation And Recreation In A System Of Protected Areas In Texas, Kellen Allison Smith Jan 2007

Providing The Best Of Both Worlds: Balancing Conservation And Recreation In A System Of Protected Areas In Texas, Kellen Allison Smith

LSU Master's Theses

Societies are becoming increasingly urban and isolated from natural areas. Protecting certain natural areas is vital for building and maintaining resilience in ecological systems for the continued conservation of biodiversity and provision of ecological services. The International Union for the Conservation of Nature and Natural Resources (IUCN) promotes the development of systems of protected areas within nations and regions as a sustainable means of preserving the biodiversity within natural areas. Allowing sustainable ecotourism and wildlife-based recreation activities in protected areas can provide economic incentives to surrounding communities making protection an attractive alternative to more extractive forms of land use. Managing …

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Rna:Dna As An Indicator Of Nutritional Condition And Growth In Larval Naked Goby, Gobiosoma Bosc, Michelle C. Satterwhite Jan 2007

Rna:Dna As An Indicator Of Nutritional Condition And Growth In Larval Naked Goby, Gobiosoma Bosc, Michelle C. Satterwhite

LSU Master's Theses

Developing organism-based metrics for assessing habitat quality is an important tool in conservation and restoration of aquatic habitats. The use of the RNA:DNA ratio as an early indicator of habitat effects on growth of nekton species has been suggested, but requires species-specific laboratory assessment prior to field application. We used food availability in laboratory treatments to simulate differences in habitat quality. Wild Gobiosoma bosc eggs were collected using nest-traps constructed of PVC pipe. Eggs from several different nests collected in the field were hatched in the lab, yielding larvae that were randomly assigned to three feeding treatments in two replicate …

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Experimental Investigation Of An Electronically Collimated Radiation Detector For Location Of Gamma-Ray Sources, William H. Hill Jr. Jan 2007

Experimental Investigation Of An Electronically Collimated Radiation Detector For Location Of Gamma-Ray Sources, William H. Hill Jr.

LSU Master's Theses

A electronically collimated prototype detector was built with commercially available cadmium zinc telluride (CZT) modules and assessed by experiment and simulation. Sensitivity was roughly equivalent to a common hand held 1"x1" NaI(Tl) detector. The maximum useful count rate was 300 counts per second (cps) per module. Overall angular error was less than 7°, which is generally less than source placement uncertainty, and angular resolution was between 20° and 40° for several common isotopes with photon energies between 511 keV and 1333 keV. Prototype data and backprojections were used to verify a simple three dimensional model of charge induction in pixellated …

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Denitrification Capacity And Denitrifying Bacteria In A Restored Bottomland Hardwood Forest, Mississippi River Alluvial Valley: Hydrological Impacts, Yan Li Jan 2007

Denitrification Capacity And Denitrifying Bacteria In A Restored Bottomland Hardwood Forest, Mississippi River Alluvial Valley: Hydrological Impacts, Yan Li

LSU Master's Theses

Mississippi River Alluvial Valley (MAV) is one of the most important ecosystems in the United States, and bottomland hardwood forests (BLHs) are a major components of this ecosystem. The ecological and hydrological functions of BLHs can help maintain the diversity of species, groundwater balance, and nutrient removal etc. However, due to the increased human activities in the area, most of the BLHs were converted to agricultural land. Realizing the seriousness of the situation of the ecosystem, a series of programs have been carried out by the U.S. Fish and Wildlife Service (USFWS) and the U.S. Department of Agriculture (USDA) to …

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Ecosystem Effects Of Expanding Populations Of Avicennia Germinans In A Southeastern Louisiana Spartina Alterniflora Saltmarsh, Carey Lynn Perry Jan 2007

Ecosystem Effects Of Expanding Populations Of Avicennia Germinans In A Southeastern Louisiana Spartina Alterniflora Saltmarsh, Carey Lynn Perry

LSU Master's Theses

Although the Earth may be in the early stages of the projected trends of global warming, several ecological responses to recent warming are already evident. The timing of seasonal activities of plants and animals has begun to shift, and the advancement of species poleward is occurring in several regions of the world. One unique distributional shift is the movement of Avicennia germinans (black mangrove) northward into temperate salt marshes dominated by the marsh grass, Spartina alterniflora. In Louisiana, black mangroves were historically restricted to the southernmost barrier islands and beaches; however, in recent years a noticeable expansion of Avicennia northward …

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Effects Of Predator Activity On The Nesting Of American Black Ducks And Other Birds On Barrier Islands In The Mid-Atlantic Coast, Brian Joseph Arquilla Jan 2007

Effects Of Predator Activity On The Nesting Of American Black Ducks And Other Birds On Barrier Islands In The Mid-Atlantic Coast, Brian Joseph Arquilla

LSU Master's Theses

Landscape change throughout North America has resulted in heightened nest predator population and declining avian productivity. Essential to establishing effective management design is an understanding of differential predation pressure among avian groups as group specific responses to predation impact may exist. The objective of this study was to examine the efficacy of predator trapping on the nest success and density of ground nesting avifauna in 2004-2005 in the Virginia Coast Reserve, specifically dabbling ducks, Canada Goose and Willet. Second, we determine the impact of predation on ground nesting birds by relating indices of predator abundance to nest density and nest …

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Environmental Factors Affecting The Distribution Of Native And Invasive Aquatic Plants In The Atchafalaya River Basin, Louisiana, U.S.A., Rachel Cathleen Walley Jan 2007

Environmental Factors Affecting The Distribution Of Native And Invasive Aquatic Plants In The Atchafalaya River Basin, Louisiana, U.S.A., Rachel Cathleen Walley

LSU Master's Theses

Over the last century, the aquatic macrophyte community of the Atchafalaya River Basin (ARB) has become increasingly dominated by invasive species. I used digital photography and GIS software to determine ARB macrophyte community composition by measuring percent cover of each plant species within five 0.25-m2 quadrats sampled from 108 sites in 2005 and 103 sites in 2006. Macrophyte community data and measurements of soil and water physicochemistry at each site were used to investigate environmental associations of the macrophytes inhabiting bayou, lake, excavated canal, and swamp habitats. Analyses indicated substantial differences in physicochemical conditions among habitats, but none of the …

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Empirical Modeling Of Late Quaternary Sediment Supply To The Gulf Of Mexico Shelf Margin In A Cool Lowstand World, Jill Hattier Womack Jan 2007

Empirical Modeling Of Late Quaternary Sediment Supply To The Gulf Of Mexico Shelf Margin In A Cool Lowstand World, Jill Hattier Womack

LSU Master's Theses

During the last glacial period, river systems responded to the lowering of sea level by incising valleys, extending across the continental shelf, and depositing deltas on the shelf margin and upper slope of surrounding basins. These deltas represent important repositories for sediment delivered to the coastal ocean and provide partial records of sediment discharged from continental landmasses. Over relatively short time scales, like that of the last glacial-interglacial cycle, hinterland drainage areas, relief and lithology can be considered constants while the primary variable of significance is climate change (Syvitski and Milliman, 2007). It is reasonable to assume, therefore, that supply …

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Carbonated Sections From Komatiite Flow- Top Alteration Zones In The Barberton Greenstone Belt: Implications For Near-Surface Archean Environments, Judith E. F. Stoute Jan 2007

Carbonated Sections From Komatiite Flow- Top Alteration Zones In The Barberton Greenstone Belt: Implications For Near-Surface Archean Environments, Judith E. F. Stoute

LSU Master's Theses

Over a dozen komatiitic flows in the 3.2-3.5 Ga Barberton Greenstone Belt are topped with unique green silica- and carbonate-rich rocks, which likely formed from interaction of the cooling lava flow with seawater shortly after deposition. This study focuses on an alteration zone in the Mendon Formation. Two styles of alteration are observed in this alteration zone: silicification and carbonation. The goal of this study is to characterize the carbonates in the alteration zone, constrain the timing of alteration, test whether the alteration zones are due to interaction with seawater after deposition, and estimate the elemental fluxes between the rock …

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Synthesis And Functionalizations Of Tetrapyrrole Derivatives, Lijuan Jiao Jan 2007

Synthesis And Functionalizations Of Tetrapyrrole Derivatives, Lijuan Jiao

LSU Doctoral Dissertations

Chapter 1 of this Dissertation presents a brief overview of the history of tetrapyrrole derivatives and of their fundamental properties. Overviews of porphyrins, benzoporphyrins, chlorins and porphycenes are presented. Work presented in Chapter 2 through Chapter 4 mainly focuses on the syntheses and functionalization of chromophore-extended porphyrin derivatives. Several new synthetic routes for the syntheses and functionalizations of extended porphyrins either at the β-position or at the meso-position of porphyrin are developed. From these improved synthetic routes, the regio-selective syntheses of porphyrin derivatives are described. Chapter 2 mainly focuses on the syntheses of β,β'-fused methylenepropanoporphyrins and related porphyrin dimers. Chapter …

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