Digital Commons Network^™

Ecological Structure Of Estaurine Fish Communities: Habitat Linkages Among Dominant Species Groups In Terminos Lagoon, Mexico., Ana Laura Lara-Dominguez

LSU Historical Dissertations and Theses

Terminos Lagoon in the southern Gulf of Mexico has 5 ecological subsystems: (1) fluvial lagoon systems (FLS) with permanent river discharge, low salinity, high turbidity and nutrients. (2) Central basin (CB) between marine and river conditions, intermediate salinity and variable transparency. (3) Inner littoral of Carmen Island (ILCI) with strong marine influence, high transparency and extensive seagrass meadows. (4) Carmen inlet (Estero Pargo, ESP) with a net outflow of water and high turbidity. (5) Puerto Real inlet (PR) with a net inflow of waters, high transparency and seagrasses. During a 15-month sampling, 13,691 individuals of 79 different species were collected …

Multiscale Analysis For Characterization Of Remotely Sensed Images., Wei Zhao

LSU Historical Dissertations and Theses

In this study we addressed fundamental characteristics of image analysis in remote sensing, enumerated unavoidable problems in spectral analysis, and highlighted the spatial structure and features that increase information amount and measurement accuracy. We addressed the relationship between scale and spatial structure and the difficulties in characterizing them in complex remotely sensed images. We suggested that it is necessary to employ multiscale analysis techniques for analyzing and extracting information from remotely sensed images. We developed a multiscale characterization software system based on an existing software called ICAMS (Image Characterization And Modeling System), and applied the system to various test data …

De Haas-Van Alphen Effect Measurements On Cerium-Lanthanum-M-Indium (M = Cobalt, Rhodium, Iridium) Alloys., Umit Alver

LSU Historical Dissertations and Theses

The de Haas van Alphen (dHvA) effect, which measures the oscillatory component of the magnetization, in several CexLa1-x MIn5 (M = Rh, Co, Ir) alloys for 0 ≤ x ≤ 1 has been studied in detail using torque, pulse field and field modulation techniques. The frequencies, associated extremal cross sectional areas of the Fermi surface and effective masses of each sample throughout each of the series are reported. The energy band calculations of CeRhIn5, CeCoIn5 and CeIrIn5 assume that the 4f electrons in Ce are completely delocalized and these electrons make a significant contribution to the topology of the Fermi …

The Synthesis Of Deuterated Arylamine Dna Adducts For Use In The Development Of An Isotope Dilution Lc/Ms/Ms Method, Philip Dmitri Olsen

LSU Doctoral Dissertations

Polycyclic aromatic amines (arylamines) are a class of chemical carcinogens that are prevalent in environmental and industrial settings. In order to study the mechanism of their toxicity a quantitative and qualitative detection method was developed to measure the C8-adenine adducts of benzidine and 2-aminofluorene in DNA samples. To do this a novel synthetic method using a palladium catalyst was developed to prepare authentic and deuterated arylamine adducts to serve as standards. These standards were then used to develop a high performance liquid chromatography, electrospray, tandem mass spectrometry, isotope dilution, detection method. To demonstrate the validity of this method two spike …

Analysis Of Near-Infrared Dye-Labeled Sanger Sequencing Fragments With Gel Electrophoresis Using The Time-Resolved Flourescence Lifetime Indentification Methods, Suzanne Jeanel Lassiter

LSU Doctoral Dissertations

The research presented in this dissertation involves the identification of sequencing fragments with time-resolved methods. For this application, near-infrared heavy-atom tricarbocyanine dyes were developed in our laboratory, which can be excited with a single laser and emission collected using a single detection channel. The dyes have four spectroscopically unique, but relatively short lifetimes that can be altered by the intramolecular heavy-atom they contain. The work described here involves the optimization of dye-primer chemistry for preparing Sanger sequencing reactions for longer reads and the optimization of the separation matrix for capillary gel electrophoresis that produces favorable statistical analysis of the aforementioned …

Bounding The Wild Set (Counting The Minimum Number Of Wild Primes In Hilbert Symbol Equivalent Number Fields), Marius M. Somodi

LSU Doctoral Dissertations

This dissertation makes a contribution to the study of Witt rings of quadratic forms over number fields. To every pair of algebraic number fields with isomorphic Witt rings one can associate a number, called the minimum number of wild primes. The situation is particularly nice when this number is 0; often it is not 0. Earlier investigations have established lower bounds for this number. In this dissertation an analysis is presented that expresses the minimum number of wild primes in terms of the number of wild dyadic primes. This formula not only gives immediate upper bounds, but can be considered …

Artin-Schreier Families And 2-D Cycle Codes, Cem Guneri

LSU Doctoral Dissertations

We start with the study of certain Artin-Schreier families. Using coding theory techniques, we determine a necessary and sufficient condition for such families to have a nontrivial curve with the maximum possible number of rational points over the finite field in consideration. This result produces several nice corollaries, including the existence of certain maximal curves; i.e., curves meeting the Hasse-Weil bound.We then present a way to represent two-dimensional (2-D) cyclic codes as trace codes starting from a basic zero set of its dual code. This representation enables us to relate the weight of a codeword to the number of rational …

Numerical Simulations Of Dynamical Mass Transfer In Binaries, Patrick Michael Motl

LSU Doctoral Dissertations

We present results from investigations of mass transfer instability in close binary star systems. By unstable mass transfer we mean the exchange of material where the response of the binary to the initial Roche lobe overflow causes the donor to loose even more material. Our work is guided by approximate arguments that dictate the stability boundaries for binary star systems. To proceed further one must explicitly treat extended mass and velocity distributions that are both nitially, and through their subsequent evolution in time, self-consistent. In this dissertation, we present the first three-dimensional, fully self-consistent treatment of mass transfer in close …

Making Classical And Quantum Canonical General Relativity Computable Through A Power Series Expansion In The Inverse Cosmological Constant, Rodolfo Gambini, Jorge Pullin

Faculty Publications

Casting ordinary general relativity as a perturbative theory in Λ-1 and starting with background theory in which Λ → ∞ allows one to explicitly compute nondegenerate physical quantum states and observables. The technique is applicable in the theory in general and also in mini-super-space models. In the general theory, the calculations are well defined and tractable, but quite involved. This opens up a program for the quantization of the gravitational field that is well defined computationally and allows contact with the physical observables of the theory, a key ingredient in the road to finding a theory with a semiclassical regime …

Land Use Impacts On Atmospheric Carbon Monoxide Consumption By Soils, G. M. King

Faculty Publications

Seasonal analyses of in situ CO fluxes from forested and agricultural soils in Maine and Georgia, and more limited comparisons in Hawai'i indicated that agricultural land use consistently enhanced CO consumption. Soils at an agricultural site in Maine consumed approximately 1.9 g CO m-2 yr-1 while uptake in a nearby mixed forest was about 70% lower, 0.6 g CO m-2 yr-1. A similar trend was observed for sites in Georgia, where annual uptake by agricultural sites was approximately 1.0 g CO m-2 while net emission (about -0.5 g CO m-2) was observed for neighboring pine stands. Net CO fluxes in …

The Large Cosmological Constant Approximation To Classical And Quantum Gravity: Model Examples, Rodolfo Gambini, Jorge Pullin

Faculty Publications

We have recently introduced an approach for studying perturbatively classical and quantum canonical general relativity. The perturbative technique appears to preserve many of the attractive features of the non-perturbative quantization approach based on Ashtekar's new variables and spin networks. With this approach one can find perturbatively classical observables (quantities that have vanishing Poisson brackets with the constraints) and quantum states (states that are annihilated by the quantum constraints). The relative ease with which the technique appears to deal with these traditionally hard problems opens up several questions concerning how relevant the results produced can possibly be. Among the questions is …

Re: 'Differences In Socioeconomic Status And Survival Among White And Black Men With Prostate Cancer' [1] (Multiple Letters), Jay S. Kaufman, Robert Millikan, Charles Poole, Paul Godley, Richard S. Cooper, Vincent Freeman

Faculty Publications

No abstract provided.

On The Excluded Minors For Quaternary Matroids, J. F. Geelen, J. G. Oxley, D. L. Vertigan, G. P. Whittle

Faculty Publications

This paper strengthens the excluded-minor characterization of GF(4)-representable matroids. In particular, it is shown that there are only finitely many 3-connected matroids that are not GF(4)-representable and that have no U2, 6-, U4, 6-, P6-, F-7-, or (F-7)*-minors. Explicitly, these matroids are all minors of S(5, 6, 12) with rank and corank at least 4, and P″8, the matroid that can be obtained from S(5, 6, 12) by deleting two elements, contracting two elements, and then relaxing the only pair of disjoint circuit-hyperplanes. © 2000 Academic Press.

Canonical Quantum Gravity In The Vassiliev Invariants Arena: Ii. Constraints, Habitats And Consistency Of The Constraint Algebra, Cayetano Di Bartolo, Rodolfo Gambini, Jorge Griego, Jorge Pullin

Faculty Publications

In a companion paper we introduced a kinematical arena for the discussion of the constraints of canonical quantum gravity in the spin network representation based on Vassiliev invariants. In this paper we introduce the Hamiltonian constraint, extend the space of states to non-diffeomorphism-invariant 'habitats' and check that the off-shell quantum constraint commutator algebra reproduces the classical Poisson algebra of constraints of general relativity without anomalies. One can therefore consider the resulting set of constraints and space of states as a consistent theory of canonical quantum gravity.

Theoretical Prediction Of Nuclear Quadrupole Resonance Spectra Of Aluminum, Bromine And Nitrogen Compounds Via First Principles Calculations, Chris Harwell

LSU Historical Dissertations and Theses

We study the interaction of the electric field gradient (EFG) and the nuclear quadrupole moment of ⁸¹Br,²⁷Al, and ¹⁴N nuclei via ab initio quantum chemistry calculations. The primary goal is to predict the nuclear magnetic resonance (NMR) spectral parameters of interesting materials and assist in interpretation of their spectra. The calculations predict NMR spectral parameters for:

1. ²⁷Al nuclei in andalusite, sillimanite and kyanite - three polymorphs of Al2Si05 - for assigning NMR signals to crystallographic sites, as a zeolite model and studying the effect of structural changes due to temperature (25-1000''C);
2. ¹⁴N nuclei in …

Classification Of The Lie Bialgebra Structures On The Witt And Virasoro Algebras, Siu Hung Ng, Earl J. Taft

Faculty Publications

We prove that all the Lie bialgebra structures on the one sided Witt algebra W1, on the Witt algebra W and on the Virasoro algebra V are triangular coboundary Lie bialgebra structures associated to skew-symmetric solutions r of the classical Yang-Baxter equation of the form r = a ∧ b. In particular, for the one-sided Witt algebra W1 = Der k[t] over an algebraically closed field k of characteristic zero, the Lie bialgebra structures discovered in Michaelis (Adv. Math. 107 (1994) 365-392) and Taft (J. Pure Appl. Algebra 87 (1993) 301-312) are all the Lie bialgebra structures on W1 up …

Iron Acquisition Systems And The Effect Of Iron On Virulence, Amy E. Noles

Honors Capstones

No abstract provided.

Gamma-Ray Bursts Have Millisecond Variability, Katharine C. Walker, Bradley E. Schaefer, E. E. Fenimore

Faculty Publications

We have performed searches for isolated flares and for steady flickering in the initial ∼ 1 s of gamma-ray burst light curves on the microsecond to millisecond timescales. Two bursts among our sample of 20 revealed four isolated flares with timescales from 256 to 2048 μs. A wavelet analysis for our sample showed low-level flickering for all bursts on timescales from 256 μs to 33 ms, with the majority of bursts containing rise times faster than 4 ms and 30% having rise times faster than 1 ms. These results show that millisecond variability is common in classical bursts and not …

Economic Implications Of Forest Products Sector Industry Development In Northwest Louisiana (Bulletin #874), David W. Hughes, Richard P. Vlosky

LSU AgCenter Bulletins

In this study, industry development opportunities specific to northwestern Louisiana were examined. This publication focuses on the economic impacts of forest products industry development in this region.

Surfaces, Tree-Width, Clique-Minors, And Partitions, Guoli Ding, Bogdan Oporowski, Daniel P. Sanders, Dirk Vertigan

Faculty Publications

In 1971, Chartrand, Geller, and Hedetniemi conjectured that the edge set of a planar graph may be partitioned into two subsets, each of which induces an outerplanar graph. Some partial results towards this conjecture are presented. One such result, in which a planar graph may be thus edge partitioned into two series-parallel graphs, has nice generalizations for graphs embedded onto an arbitrary surface and graphs with no large clique-minor. Several open questions are raised. © 2000 Academic Press.

On Size, Circumference And Circuit Removal In 3-Connected Matroids, Manoel Lemos, James Oxley

Faculty Publications

This paper proves several extremal results for 3-connected matroids. In particular, it is shown that, for such a matroid M, (i) if the rank r(M) of M is at least six, then the circumference c(M) of M is at least six and, provided |E(M)| ≥4r(M) - 5, there is a circuit whose deletion from M leaves a 3-connected matroid; (ii) if r(M) ≥4 and M has a basis B such that M\e is not 3-connected for all e in E(M) - B, then |E(M)| ≤3r(M) - 4; and (iii) if M is minimally 3-connected but not hamiltonian, then |E(M)| ≤3r(M) …

Moving Mountains: Serving In 10 States, An Engineer's Final Project Is Battery Wagner, Charles D. Ross

Civil War Book Review

For several centuries, combat engineers have played a crucial role in battle operations. Yet the typical battles and leaders approach to the Civil War usually pays little attention to this important work. George G. Kundahl attempts to fill the void with Confederate Engineer: Training and Campaign....