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2008

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Articles 5821 - 5850 of 5871

Full-Text Articles in Physical Sciences and Mathematics

Colloid Mediated Transport Of Heavy Metals In Soils Following Reclamation With And Without Biosolid Application, Jarrod O. Miller Jan 2008

Colloid Mediated Transport Of Heavy Metals In Soils Following Reclamation With And Without Biosolid Application, Jarrod O. Miller

University of Kentucky Doctoral Dissertations

Soils disturbed by strip mining practices may have increased colloid loads moving to groundwater resources, also enhancing the transport of contaminants into our water resources. We hypothesize that contaminant transport within soils following mining is enhanced by colloid mobility. Two sites were chosen for this study, a 30-year old reclaimed strip mine in southwest Virginia and a recently mined area from eastern Kentucky. Intact reclaimed soil monoliths were retrieved from sandstone derived soils in southwestern Virginia. Reclaimed monoliths from eastern Kentucky were recreated in the lab. Intact undisturbed (native) soil monoliths representing the soils before mining were also sampled for …


Algebraic Properties Of Edge Ideals, Rachelle R. Bouchat Jan 2008

Algebraic Properties Of Edge Ideals, Rachelle R. Bouchat

University of Kentucky Doctoral Dissertations

Given a simple graph G, the corresponding edge ideal IG is the ideal generated by the edges of G. In 2007, Ha and Van Tuyl demonstrated an inductive procedure to construct the minimal free resolution of certain classes of edge ideals. We will provide a simplified proof of this inductive method for the class of trees. Furthermore, we will provide a comprehensive description of the finely graded Betti numbers occurring in the minimal free resolution of the edge ideal of a tree. For specific subclasses of trees, we will generate more precise information including explicit formulas for …


The H-Vectors Of Matroids And The Arithmetic Degree Of Squarefree Strongly Stable Ideals, Erik Stokes Jan 2008

The H-Vectors Of Matroids And The Arithmetic Degree Of Squarefree Strongly Stable Ideals, Erik Stokes

University of Kentucky Doctoral Dissertations

Making use of algebraic and combinatorial techniques, we study two topics: the arithmetic degree of squarefree strongly stable ideals and the h-vectors of matroid complexes.

For a squarefree monomial ideal, I, the arithmetic degree of I is the number of facets of the simplicial complex which has I as its Stanley-Reisner ideal. We consider the case when I is squarefree strongly stable, in which case we give an exact formula for the arithmetic degree in terms of the minimal generators of I as well as a lower bound resembling that from the Multiplicity Conjecture. Using this, we can …


Charge Density Wave Polarization Dynamics, Luis Alejandro Ladino Gaspar Jan 2008

Charge Density Wave Polarization Dynamics, Luis Alejandro Ladino Gaspar

University of Kentucky Doctoral Dissertations

We have studied the charge density wave (CDW) repolarization dynamics in blue bronze (K0.3MoO3) by applying symmetric bipolar square-wave voltages of different frequencies to the sample and measuring the changes in infrared transmittance, proportional to CDW strain. The frequency dependence of the electro-transmittance was fit to a modified harmonic oscillator response and the evolution of the parameters as functions of voltage, position, and temperature are discussed. We found that resonance frequencies decrease with distance from the current contacts, indicating that the resulting delays are intrinsic to the CDW with the strain effectively flowing from the contact. …


Paleogene Mirelands Of The Upper Mississippi Embayment, Western Kentucky, Jennifer Marie Klein O'Keefe Jan 2008

Paleogene Mirelands Of The Upper Mississippi Embayment, Western Kentucky, Jennifer Marie Klein O'Keefe

University of Kentucky Doctoral Dissertations

Detailed petrography, geochemistry, and palynology together describe the depositional environments and paleoecology of an abandoned meander-fill system in western Kentucky. Oriented block petrography reveals alternating clay-rich and attrinite-rich zones of variable thickness. Woody tissues, where present, do not show dessication features and deflation layers could not be identified. Overall, petrography is indicative of a topogenous mire. Mire palyno-assemblages are less diverse than assemblages reported from clays in the region. Castanea-Cupuliferoidaepollenites assemblages dominate the entire system and other tree pollen are common; fungal spores are relatively uncommon. Weighted statistical analyses reveal ecological groupings beyond this dominance and define botanical succession within …


Avoidance Of Hydrolyzed Casein By Mice, Kristin L. Field, Bruce A. Kimball, Julie A. Mennella, Gary K. Beauchamp, Alexander A. Bachmanov Jan 2008

Avoidance Of Hydrolyzed Casein By Mice, Kristin L. Field, Bruce A. Kimball, Julie A. Mennella, Gary K. Beauchamp, Alexander A. Bachmanov

United States Department of Agriculture Wildlife Services: Staff Publications

When casein, a milk protein, is hydrolyzed, it renders human foods that contain it (e.g., hypoallergenic infant formula, cheeses) distasteful to many people. This rejection of hydrolyzed casein (HC)-containing foods has recently been found to also occur in a non-human species (deer, Odocoileus spp.). Identifying other animals that avoid HC would facilitate understanding how and why HC-containing food is often rejected. This study determined whether HC-containing food is avoided by Mus musculus and whether consumption patterns were sensitive to testing conditions, specifically food form (powder, pellet or dough) and food access (ad libitum or 1.5 h/day following 6 h …


Evaluation Of Stop-Level Vs. Route-Level Breeding Bird Survey Counts For Modeling The Influence Of Land Use And Climate On Breeding Blackbird Abundance In North Dakota, Michelle L. Petersen, George M. Linz, Greg Forcey, Wayne Thogmartin, William J. Bleier Jan 2008

Evaluation Of Stop-Level Vs. Route-Level Breeding Bird Survey Counts For Modeling The Influence Of Land Use And Climate On Breeding Blackbird Abundance In North Dakota, Michelle L. Petersen, George M. Linz, Greg Forcey, Wayne Thogmartin, William J. Bleier

United States Department of Agriculture Wildlife Services: Staff Publications

The Red-winged Blackbird (Agelaius phoeniceus), Yellow-headed Blackbird (Xanthocephalus xanthocephalus), and Common Grackle (Quiscalus quiscula) are the three most abundant blackbird species (Icteridae) found in North Dakota and comprise almost 10% of its avian population (Stewart and Kantrud 1972). Blackbird abundance combined with their food habitats make them significant agricultural pests on sunflower. Cost estimates for blackbird damage to sunflower in the North Dakota are likely over $10 million dollars annually (Kleingartner, pers. comm). Because of this economic impact blackbirds have on agriculture, it is important to understand land use and climatic factors influencing blackbird …


Development Of Polymorphic Microsatellite Loci For The Common Vampire Bat, Desmodus Rotundus (Chiroptera: Phylostomidae), Antoinette J. Piaggio, John J. Johnston, Susan L. Perkins Jan 2008

Development Of Polymorphic Microsatellite Loci For The Common Vampire Bat, Desmodus Rotundus (Chiroptera: Phylostomidae), Antoinette J. Piaggio, John J. Johnston, Susan L. Perkins

United States Department of Agriculture Wildlife Services: Staff Publications

The common vampire bat (Desmodus rotundus) is one of three haematophagous species of bats and the only species in this genus. These New World bats prey on mammals and create significant economic impacts through transmission of rabies in areas where livestock are prevalent. Furthermore, in some portions of their range, it is not uncommon for them to prey upon humans. It is critical to the management of this species and for understanding the spread of bat rabies that detailed studies of D. rotundus population structure be conducted. To further such studies, we have characterized 12 microsatellite loci for …


Isolation Of Microsatellite Loci From The Coqui Frog, Eleutherodactylus Coqui, Maureen B. Peters, Karen H. Beard, Cris Hagen, Eric M. O'Neill, Karen E. Mock, William Pitt Jan 2008

Isolation Of Microsatellite Loci From The Coqui Frog, Eleutherodactylus Coqui, Maureen B. Peters, Karen H. Beard, Cris Hagen, Eric M. O'Neill, Karen E. Mock, William Pitt

United States Department of Agriculture Wildlife Services: Staff Publications

Thirteen microsatellite loci were isolated from the coqui frog (Eleutherodactylus coqui) and optimized for future research. The loci were screened across 37 individuals from two Puerto Rican populations. Loci were variable with the number of alleles per locus ranging from three to 38. Polymorphic information content ranged from 0.453 to 0.963 and observed heterozygosity for each population ranged from 0.320 to 0.920.


Evaluation Of An Electrified Mat As A White-Tailed Deer (Odocoileus Virginianus) Barrier, Thomas W. Seamans, David A. Helon Jan 2008

Evaluation Of An Electrified Mat As A White-Tailed Deer (Odocoileus Virginianus) Barrier, Thomas W. Seamans, David A. Helon

United States Department of Agriculture Wildlife Services: Staff Publications

White-tailed deer (Odocoileus virginianus) pose economic and safety problems for agricultural and transportation industries. We tested an electronic mat to determine if it would reduce deer crossing through fence openings. We measured deer intrusions and corn consumption at five sites with charged mats and five sites with non-charged mats. Weekly intrusions at treated sites decreased an average of 95% from pre-treatment. Weekly intrusions at control sites were reduced 60% during weeks 1 and 2 and increased to 10% reduction by week 6. Weekly corn consumption at treated sites decreased from pretreatment through all treatment weeks. Weekly corn consumption …


Estimating The Efficacy Of Drc-1339-Treated Rice Bait In Blackbird Staging Areas In North Dakota Using A Bioenergetics Simulation, Randal S. Stahl, John J. Johnston, George M. Linz Jan 2008

Estimating The Efficacy Of Drc-1339-Treated Rice Bait In Blackbird Staging Areas In North Dakota Using A Bioenergetics Simulation, Randal S. Stahl, John J. Johnston, George M. Linz

United States Department of Agriculture Wildlife Services: Staff Publications

DRC-1339 is a pesticide used to induce mortality in pest birds and is being used successfully to reduce bird damage to a variety of agricultural products. The feasibility of using live decoy traps baited with DRC-1339-treated rice baits is being evaluated for reducing blackbird damage to sunflower in North Dakota. To estimate the take associated with the use of the DRC-1339-treated rice baits, we developed a bioenergetics simulation to estimate bait consumption by red-winged blackbirds, yellow-headed blackbirds and common grackles. This simulation incorporates a module to estimate mortality based on the amount of treated bait eaten by individual birds and …


Managing Deer Damage In Nebraska, Scott E. Hygnstrom, Stephen M. Vantassel, Bruce D. Trindle, Kurt C. Vercauteren Jan 2008

Managing Deer Damage In Nebraska, Scott E. Hygnstrom, Stephen M. Vantassel, Bruce D. Trindle, Kurt C. Vercauteren

United States Department of Agriculture Wildlife Services: Staff Publications

Deer browse a variety of plants, especially when densities are high or forage is limited. This browsing can damage trees, plants, vines, and fruit. This guide discusses how to recognize, manage, and minimize deer damage.


The Single-Shot Gnrh Immunocontraceptive Vaccine (GonaconTm ) In White-Tailed Deer: Comparison Of Several Gnrh Preparations, Lowell A. Miller, James P. Gionfriddo, Kathleen A. Fagerstone, Jack C. Rhyan, Gary J. Killian Jan 2008

The Single-Shot Gnrh Immunocontraceptive Vaccine (GonaconTm ) In White-Tailed Deer: Comparison Of Several Gnrh Preparations, Lowell A. Miller, James P. Gionfriddo, Kathleen A. Fagerstone, Jack C. Rhyan, Gary J. Killian

United States Department of Agriculture Wildlife Services: Staff Publications

Problem: An effective, single-injection, multi-year, GnRH contraceptive agent is needed to control reproduction in overabundant white-tailed deer populations.

Method of study: Two GnRH conjugates, GonaConTM (GnRH–KLH) and GonaCon-BTM (GnRH–blue protein), were prepared in emulsion form as one-injection and two-injection immunocontraceptive vaccine formulations. In addition, the GnRH–KLH protein conjugate was lyophilized and suspended in AdjuVacTM adjuvant to produce a fifth vaccine formulation. Each formulation was administered to a group of five captive adult female white-tailed deer. Reproductive performance of treated female deer was monitored for 5 years to determine the comparative efficacy of the various treatments.

Results: The …


Deer Impact On Vegetation In Natural Areas In Southeastern Nebraska, Joseph Gubanyi, Julie A. Savidge, Scott E. Hygnstrom, Kurt C. Vercauteren, Gary W. Garabrandt, Seth Korte Jan 2008

Deer Impact On Vegetation In Natural Areas In Southeastern Nebraska, Joseph Gubanyi, Julie A. Savidge, Scott E. Hygnstrom, Kurt C. Vercauteren, Gary W. Garabrandt, Seth Korte

United States Department of Agriculture Wildlife Services: Staff Publications

We studied the effect of browsing by white-tailed deer (Odocoileus virginianus Zimmerman) on vegetation at three sites with high densities of deer and six sites with low densities of deer along the Missouri and Platte Rivers in southeastern Nebraska in 1995-1996. Vegetation volume from 0-1 m high was similar between sites with high and low deer densities (P > 0.05). From 1-2 m high, vegetation volume was less at sites with more deer in both years (P < 0.05). Densities for eight of 11 small woody plant categories (< 3 cm dbh) were less common at sites with high densities of deer (P < 0.05). Overall densities of small trees (3-15 cm dbh) were similar between sites with high and low densities of deer. However, small hackberry trees (Celtis occidentalis L.) were more common (P = 0.03), while all other small trees were less common (P = 0.038), at sites with …


An Integrated Vehicle-Mounted Telemetry System For Vhf Telemetry Applications, Jason Gilsdorf, Kurt C. Vercauteren, Scott E. Hygnstrom, W. David Walter, Justin Boner, Greg Clements Jan 2008

An Integrated Vehicle-Mounted Telemetry System For Vhf Telemetry Applications, Jason Gilsdorf, Kurt C. Vercauteren, Scott E. Hygnstrom, W. David Walter, Justin Boner, Greg Clements

United States Department of Agriculture Wildlife Services: Staff Publications

We designed and developed a vehicle-mounted very high frequency–based telemetry system that integrated an on-board antenna, receiver, electronic compass, Global Positioning System, computer, and Geographic Information System. The system allows users to accurately and quickly obtain fixes, estimate and confirm locations of radio-marked animals, and immediately record data into an electronic spreadsheet or database. The total cost of materials to build the system was $7,349 (United States currency). Mean error angle of 2.63 ± 12.1° (SD; range =-33.7–42.2°) and mean location error distance of 128 ± 91.3 m (SD; range = 0–408 m) suggested precision and accuracy of our system …


Livestock Protection Dogs For Deterring Deer From Cattle And Feed, Kurt C. Vercauteren, Michael J. Lavelle, Gregory Phillips Jan 2008

Livestock Protection Dogs For Deterring Deer From Cattle And Feed, Kurt C. Vercauteren, Michael J. Lavelle, Gregory Phillips

United States Department of Agriculture Wildlife Services: Staff Publications

Disease transmission between wildlife and livestock is a worldwide issue. Society needs better methods to prevent interspecies transmission to reduce disease risks. Producers have successfully used livestock protection dogs (LPDs) for thousands of years to reduce predation. We theorized that LPDs raised and bonded with cattle could be used to also reduce risk of bovine tuberculosis (Myobacterium bovis; TB) transmission between white-tailed deer (Odocoileus virginianus) and cattle by minimizing contact between the 2 species and use of cattle feed by deer. We evaluated 4 LPDs over 5 months, utilizing 2 data collection methods (direct observation and …


Correlates Of Tobacco Cessation Counseling Among Hispanic Physicians In The Us: A Cross-Sectional Survey Study, Francisco G Soto Mas, Héctor G Balcázar, Julia Valderrama Alberola, Chiehwen Ed Hsu Jan 2008

Correlates Of Tobacco Cessation Counseling Among Hispanic Physicians In The Us: A Cross-Sectional Survey Study, Francisco G Soto Mas, Héctor G Balcázar, Julia Valderrama Alberola, Chiehwen Ed Hsu

Faculty, Staff and Student Publications

BACKGROUND: Physician advice is an important motivator for attempting to stop smoking. However, physicians' lack of intervention with smokers has only modestly improved in the last decade. Although the literature includes extensive research in the area of the smoking intervention practices of clinicians, few studies have focused on Hispanic physicians. The purpose of this study was to explore the correlates of tobacco cessation counseling practices among Hispanic physicians in the US. METHODS: Data were collected through a validated survey instrument among a cross-sectional sample of self-reported Hispanic physicians practicing in New Mexico, and who were members of the New Mexico …


Geochemical Analysis Of Ironstone Preserved Molluscan Fossils Of The Hell Creek Formation (Cretaceous) And Ludlow Member Of The Fort Union Formation (Paleogene) Of Southwestern North Dakota, Tanya P. Justham Jan 2008

Geochemical Analysis Of Ironstone Preserved Molluscan Fossils Of The Hell Creek Formation (Cretaceous) And Ludlow Member Of The Fort Union Formation (Paleogene) Of Southwestern North Dakota, Tanya P. Justham

Theses and Dissertations

The uppermost Cretaceous Hell Creek Formation and Paleocene Ludlow Member of the Fort Union Formation in easternmost Montana and western North Dakota produce ironstone preserved freshwater molluscan fossils. Ironstone preserved mollusks are associated with ironstone nodules, which have been described as composed of iron carbonate, iron oxide, or manganese oxide by various researchers. To date, the exact composition of the ironstone preservation has not been satisfactorily determined to allow agreement between researchers. Freshwater mollusk fossils, preserved as ironstone external casts, molds, and steinkerns, tend to be highly weathered. The poor preservation of the fossils has resulted in little professional interest, …


A Multi-Tracer Study Of Saltwater Origin, Cross-Formational Flow, And The Geochemical Evolution Of Groundwater In The Southern High Plains Aquifer Along The Western Caprock Escarpment, East-Central New Mexico, Jeff Langman Jan 2008

A Multi-Tracer Study Of Saltwater Origin, Cross-Formational Flow, And The Geochemical Evolution Of Groundwater In The Southern High Plains Aquifer Along The Western Caprock Escarpment, East-Central New Mexico, Jeff Langman

Open Access Theses & Dissertations

Sustainable management of groundwater resources requires sufficient knowledge of the distribution of fresh and saline groundwater and the processes affecting saltwater intrusion that may influence the beneficial use of groundwater. A hydrogeologic investigation that coupled various chemical and isotopic tracers, including 3H/3He, 14C, δD, δ18O, 87Sr/86Sr, and δ11B, with the physical characteristics of the aquifer was conducted to determine source waters, the origin of saltwater and its influence through cross-formational flow, and water-rock interactions in the Southern High Plains aquifer along the Western Caprock Escarpment. Sub-aquifers or local flow systems are present along the Western Caprock Escarpment, and the study …


Differences In The Performance Of Knowledge Transfer Across Projects: A Study Of Gender And Role Of Key Project Stakeholders, Rafael E. Landaeta, Catherine Vergopia, Rey N. Diaz Jan 2008

Differences In The Performance Of Knowledge Transfer Across Projects: A Study Of Gender And Role Of Key Project Stakeholders, Rafael E. Landaeta, Catherine Vergopia, Rey N. Diaz

Engineering Management & Systems Engineering Faculty Publications

This investigation contributes empirical results of differences identified in key project stakeholders with respect to their use of knowledge transferred across projects. Gender and role were the two individual characteristics investigated. Project managers and members of project teams were the key stakeholders analyzed. Data was collected from 71 closed projects using a survey composed of closed-ended questions. The data collected was cross tabulated and statistically analyzed using Friedman's test and Spearman's correlation. The results provide evidence of the association of the performance of knowledge transfer across projects with (a) the individual factors of gender and role of key project stakeholders …


Lead Concentration Of Soils In Sorby Hills Area Of Proposed M2 Irrigation Area, East Kimberley, Edward (Ted) Arnold Griffin, Noel R. Schoknecht, Ross Brennan, Jane Speijers, Dave Allen, Mike Freeman Jan 2008

Lead Concentration Of Soils In Sorby Hills Area Of Proposed M2 Irrigation Area, East Kimberley, Edward (Ted) Arnold Griffin, Noel R. Schoknecht, Ross Brennan, Jane Speijers, Dave Allen, Mike Freeman

Resource management technical reports

No abstract provided.


Climate Change, Vulnerability And Adaptation For South-West Western Australia: Phase One Of Action 5.5, Western Australian Greenhouse Strategy, Luke Morgan, Jo Anne Molin, Ross George, Richard Mckellar, Janet Conte Jan 2008

Climate Change, Vulnerability And Adaptation For South-West Western Australia: Phase One Of Action 5.5, Western Australian Greenhouse Strategy, Luke Morgan, Jo Anne Molin, Ross George, Richard Mckellar, Janet Conte

Bulletins 4000 -

This report outlines preliminary findings about the impacts of climate changes that occurred during 1975 to 2005 on the South West’s people, its economy and natural ecosystems. The report focuses on vulnerability and adaptation, identifying useful pointers for future work, particularly in relation to how well the community, stakeholders and decision-makers understand climate change as an issue and a threat.


Glacial Ecosystems, Amy Hodson, Alexandre M. Anesio, Martyn Tranter, Andrew G. Fountain, Mark Osborn, John Charles Priscu, Johanna Laybourn-Perry, Birgit Sattler Jan 2008

Glacial Ecosystems, Amy Hodson, Alexandre M. Anesio, Martyn Tranter, Andrew G. Fountain, Mark Osborn, John Charles Priscu, Johanna Laybourn-Perry, Birgit Sattler

Geography Faculty Publications and Presentations

There is now compelling evidence that microbially mediated reactions impart a significant effect upon the dynamics, composition, and abundance of nutrients in glacial melt water. Consequently, we must now consider ice masses as ecosystem habitats in their own right and address their diversity, functional potential, and activity as part of alpine and polar environments. Although such research is already underway, its fragmentary nature provides little basis for developing modern concepts of glacier ecology. This paper therefore provides a much-needed framework for development by reviewing the physical, biogeochemical, and microbiological characteristics of microbial habitats that have been identified within glaciers and …


Agricultural Systems: Agroecology And Rural Innovations For Development [Book Review], Charles A. Francis Jan 2008

Agricultural Systems: Agroecology And Rural Innovations For Development [Book Review], Charles A. Francis

Department of Agronomy and Horticulture: Faculty Publications

To welcome yet another book on sustainable development, a reviewer must look for what is unique and what adds value to the volumes already published. In Agricultural Systems, editors Sieglinde Snapp and Barry Pound have assembled a collection of chapters that goes beyond the usual praise and criticism of the green revolution and the focus on economic development. Their book provides a first-hand story by people with lengthy experiences in the field, especially in Africa, who have developed and tested grassroots, participatory development approaches. The result is a valuable set of principles, strategies and case studies that paint a new …


Landscape Analysis Of Vegetation Change In Coastal Louisiana Following Hurricanes Katrina And Rita, Gregory Dean Steyer Jan 2008

Landscape Analysis Of Vegetation Change In Coastal Louisiana Following Hurricanes Katrina And Rita, Gregory Dean Steyer

LSU Doctoral Dissertations

Investigations of hurricane disturbances on coastal vegetated communities are common, but relatively few are comprehensive across broad geographic regions. The 2005 hurricanes, Katrina and Rita, exposed Louisiana coastal landscapes to physical modifications and extensive and prolonged flooding, resulting in measurable physicochemical changes. This research used remote sensing and field investigations to regionally assess (1) porewater salinity and sulfide impacts to and recovery of coastal Louisiana vegetation communities, and (2) the importance of mineral sediment deposition on accretionary processes. Hurricane effects were most direct and prominent in eastern Louisiana from Katrina and western Louisiana from Rita, compared to central Louisiana exposed …


Data Assimilation And Visualization For Ensemble Wildland Fire Models, Soham Chakraborty Jan 2008

Data Assimilation And Visualization For Ensemble Wildland Fire Models, Soham Chakraborty

University of Kentucky Master's Theses

This thesis describes an observation function for a dynamic data driven application system designed to produce short range forecasts of the behavior of a wildland fire. The thesis presents an overview of the atmosphere-fire model, which models the complex interactions between the fire and the surrounding weather and the data assimilation module which is responsible for assimilating sensor information into the model. Observation plays an important role in data assimilation as it is used to estimate the model variables at the sensor locations. Also described is the implementation of a portable and user friendly visualization tool which displays the locations …


Phylogenetic Methods For Testing Significant Codivergence Between Host Species And Their Symbionts, Skyler Speakman Jan 2008

Phylogenetic Methods For Testing Significant Codivergence Between Host Species And Their Symbionts, Skyler Speakman

University of Kentucky Master's Theses

Significant phylogenetic codivergence between plant or animal hosts (H) and their symbionts or parasites (P) indicate the importance of their interactions on evolutionary time scales. However, valid and realistic methods to test for codivergence are not fully developed. One of the systems where possible codivergence has been of interest involves the large subfamily of temperate grasses (Pooideae) and their endophytic fungi (epichloae). Here we introduce the MRCALink (most-recent-common-ancestor link) method and use it to investigate the possibility of grass-epichloё codivergence. MRCALink applied to ultrametric H and P trees identifies all corresponding nodes for pairwise comparisons of …


The Development Of A Novel And Potentially Nondestructive Pretreatment For The Radiocarbon Dating Of Archaeological Artifacts, Mary Ellen Ellis Jan 2008

The Development Of A Novel And Potentially Nondestructive Pretreatment For The Radiocarbon Dating Of Archaeological Artifacts, Mary Ellen Ellis

Master's Theses and Doctoral Dissertations

Because the traditional acid-alkali-acid method for pretreating archaeological artifacts prior to radiocarbon dating is destructive to most materials, the possibility of developing an alternative pretreatment is important to preserving culturally- and historically-significant artifacts. The alkali step usually involves a 1M or higher concentration NaOH wash to remove humic acid contamination. The purpose of this work is to replace the alkali step with an equally effective, yet less harsh treatment. Charcoal soaked in a humic acid standard was used to mimic a contaminated artifact. Residues from treatments with NaOH, phosphate buffer (pH 8), and deionized water were characterized using THM-GC-MS. Preliminary …


Multigrid Convergence For Second Order Elliptic Problems With Smooth Complex Coefficients, Jay Gopalakrishnan, Joseph E. Pasciak Jan 2008

Multigrid Convergence For Second Order Elliptic Problems With Smooth Complex Coefficients, Jay Gopalakrishnan, Joseph E. Pasciak

Mathematics and Statistics Faculty Publications and Presentations

The finite element method when applied to a second order partial differential equation in divergence form can generate operators that are neither Hermitian nor definite when the coefficient function is complex valued. For such problems, under a uniqueness assumption, we prove the continuous dependence of the exact solution and its finite element approximations on data provided that the coefficients are smooth and uniformly bounded away from zero. Then we show that a multigrid algorithm converges once the coarse mesh size is smaller than some fixed number, providing an efficient solver for computing discrete approximations. Numerical experiments, while confirming the theory, …


Asymptotic And Numerical Techniques For Resonances Of Thin Photonic Structures, Jay Gopalakrishnan, Shari Moskow, Fadil Santosa Jan 2008

Asymptotic And Numerical Techniques For Resonances Of Thin Photonic Structures, Jay Gopalakrishnan, Shari Moskow, Fadil Santosa

Mathematics and Statistics Faculty Publications and Presentations

We consider the problem of calculating resonance frequencies and radiative losses of an optical resonator. The optical resonator is in the form of a thin membrane with variable dielectric properties. This work provides two very different approaches for doing such calculations. The first is an asymptotic method which exploits the small thickness and high index of the membrane. We derive a limiting resonance problem as the thickness goes to zero, and for the case of a simple resonance, find a first order correction. The limiting problem and the correction are in one less space dimension, which can make the approach …