Physical Sciences and Mathematics Commons^™

A New Approach To The Toxicity Testing Of Carbon-Based Nanomaterials: The Clonogenic Assay, Eva Herzog, Alan Casey, Fiona Lyng, Gordon Chambers, Hugh Byrne, Maria Davoren

Articles

The cellular toxicity of three types of carbon nanoparticles, namely HiPco® single-walled carbon nanotubes (SWCNT), arc dischargeSWCNTand Printex 90 carbon black nanoparticles,was studied on three different cell models including the human alveolar carcinoma epithelial cell line (A549), the normal human bronchial epithelial cell line (BEAS-2B) and the human keratinocyte cell line (HaCaT) using the clonogenic assay. Carbon nanomaterials are known to interact with colorimetric indicator dyes frequently used in cytotoxicity assays. By employing the clonogenic assay, any such interactions could be avoided, allowing a more reliable method for the in vitro toxicity assessment of carbon-based nanoparticles. It could be shown …

Biogeography And The Cambrian Radiation Of Arachnomorph Arthropods, Jonathan R. Hendricks, Bruce S. Lieberman

Faculty Publications

Biogeographic patterns in primarily Cambrian arachnomorph taxa are investigated using a recently constructed phylogenetic hypothesis in order to explore the biogeographic context of the Cambrian radiation. A modified version of Brooks Parsimony Analysis is employed to elucidate patterns of vicariance and geodispersal in taxa from six regions (Laurentia, Baltica, Siberia, Australia, Africa and China). Well resolved vicariance and geodispersal trees are very similar and reconstruct Laurentia and China as sister areas. This close area relationship between Laurentia and China provides extensive evidence for congruent vicariance and range expansion in Cambrian arachnomorphs, while data from trilobites do not show this pattern. …

Comment: Boosting Algorithms: Regularization, Prediction And Model Fitting, A. Buja, David Mease, A. Wyner

Faculty Publications

The authors are doing the readers of Statistical Science a true service with a well-written and up-to-date overview of boosting that originated with the seminal algorithms of Freund and Schapire. Equally, we are grateful for high-level software that will permit a larger readership to experiment with, or simply apply, boosting-inspired model fitting. The authors show us a world of methodology that illustrates how a fundamental innovation can penetrate every nook and cranny of statistical thinking and practice. They introduce the reader to one particular interpretation of boosting and then give a display of its potential with extensions from classification (where …

A Model-Driven Approach To Job/Task Composition In Cluster Computing, Yogesh Kanitkar, Konstantin Läufer, Neeraj Mehta, George K. Thiruvathukal

Computer Science: Faculty Publications and Other Works

In the general area of high-performance computing, object-oriented methods have gone largely unnoticed. In contrast, the Computational Neighborhood (CN), a framework for parallel and distributed computing with a focus on cluster computing, was designed from ground up to be object-oriented. This paper describes how we have successfully used UML in the following model-driven, generative approach to job/task composition in CN. We model CN jobs using activity diagrams in any modeling tool with support for XMI, an XML-based external representation of UML models. We then export the activity diagrams and use our XSLT-based tool to transform the resulting XMI representation to …

Urban Sustainability Through Green Building, Andrea Anzalone, Virginia Sawyer, Robert Woolsey

UNLV Theses, Dissertations, Professional Papers, and Capstones

This analysis is presented on urban sustainability through the use of "green building" in the City of Las Vegas, Nevada. This paper discusses the current practices used by the City of Las Vegas and compares them to the top 5 sustainable cities throughout the United States (as identified by the U.S. Green Building Council). Through comparison of nationwide initiatives and policies, this paper outlines recommendations the City of Las Vegas can adopt to increase their position as one of the leading sustainable cities.

Investigation Of Phospholipid Tubule Morphology For Use In Drug Delivery, Colleen Colson Garrett

LSU Doctoral Dissertations

Spherical vesicles consisting of phosphatidylcholines in which diacetylene groups have been inserted in the hydrocarbon tail centers give rise to hollow cylindrical tubes, known as “tubules”. The study of tubules has become an area of intense interest in recent years due to their unusual morphology, which raises several profound theoretical issues and suggests their use in a variety of applications. Tubule hollowness suggests medical and industrial encapsulations as well as filtration and purification applications. These potential uses, e.g., for drug and gene delivery, requires optimization of their morphology for the application. Tubules have many technologically desirable properties, such as a …

Establishment And Chemical Analysis Of Hairy Roots Of Eucommia Ulmoides, Xiaojun Wu

LSU Doctoral Dissertations

The bark of Eucommia ulmoides Oliver (Eucommiaceae) has been used over thousands of years as a folk remedy. Extracts from the bark exhibit multiple pharmacological functions, especially in lowering blood pressure. Geniposidic acid (GA), pinoresinol diglucoside (PG) and chlorogenic acid (CA) are three compounds isolated from the bark of the Eucommia tree, which display enormous bioactivities. As a type of plant tissue culture, the hairy root culture system displays prospective application over traditional cell or callus cultures, which are characterized by rapid growth, and stable biochemical and genetic capacity. The present dissertation discusses the establishment and chemical analysis of E. …

Wet And Dry Aging Of Polymer-Asphalt Blends: Chemistry And Performance, Ionela Chiparus Glover

LSU Doctoral Dissertations

A PG 76-22 Polymer Modified Asphalt Cement composition was subjected in the laboratory to accelerated aging using both a standard Thin Film Oven Test and a Pressure Aging Vessel. Conditions simulating wet atmospheres (PAV in saturated water vapors) as well as very long service terms (multiple dry and wet PAV operations) were studied. A Rotating Cylinder Aging Test has been employed as an alternate asphalt aging technique using the same PMAC composition in order to observe the initial phases of the oxidative aging process. The data provided by this technique was correlated with the actual aging in the field of …

Design, Synthesis, And Conformational Studies Of Peptides Containing α,α-Disubstituted Amino Acids, Jia Wang

LSU Doctoral Dissertations

C^α,α-disubstituted amino acids (ααAAs) are widely utilized to conformationally constrain peptides. Several pentapeptides containing dipropylglycine (Dpg) at alternating positions and their α-amino acid counterpart L-norvaline (Nva) analogues were synthesized to fully investigate the impact of Dpg on peptide backbone structure in aqueous solution. CD, VCD and NMR spectral analysis suggest that Dpg containing peptides adopt more ordered structures relative to their Nva containing analogues. The central residues (Ala, Thr, Tyr, Val) and the charged side-chains of Glu and Lys play important roles in the degree of peptide folding. Hydrophobic and branched residues (Val, Tyr) at the …

The Effects Of Trawling And Habitat Use On Red Snapper And The Associated Community, Robert Joseph David Wells

LSU Doctoral Dissertations

The primary impediment to the recovery of Gulf of Mexico (GOM) red snapper is believed to be high levels of bycatch of age 0 and age 1 individuals in shrimp trawls. Thus, conservation of GOM red snapper involves evaluating both habitat-specific function and effects of shrimp trawls on red snapper and the associated benthic ecosystem. The two goals of this study were to evaluate the effects commercial shrimp trawls have on juvenile red snapper life history parameters, on associated fish and invertebrate communities and their habitat, and to identify essential fish habitat (EFH) for red snapper by applying all four …

Probing The Association Behavior Of Hydrophobic Organic Compounds With Dissolved Humic Materials, Hadi M. Marwani

LSU Doctoral Dissertations

The association mechanism between hydrophobic organic compounds (HOC) and dissolved humic materials (DHM) has continued to be one of the interesting areas in environmental applications. The goal of the research reported in this dissertation is to investigate the association behavior of HOC with DHM. The first part of this research involves steady-state fluorescence measurements of these multi-component systems to study the effect of DHM content on the association mechanism of HOC, in particular using pyrene as a model. Results showed that steady-state fluorescence alone may not provide enough information about the quenching mechanism of pyrene with DHM. Lifetime based fluorescence …

Computer Simulation And Modeling Of Physical And Biological Processes Using Partial Differential Equations, Wensheng Shen

University of Kentucky Doctoral Dissertations

Scientific research in areas of physics, chemistry, and biology traditionally depends purely on experimental and theoretical methods. Recently numerical simulation is emerging as the third way of science discovery beyond the experimental and theoretical approaches. This work describes some general procedures in numerical computation, and presents several applications of numerical modeling in bioheat transfer and biomechanics, jet diffusion flame, and bio-molecular interactions of proteins in blood circulation.

A three-dimensional (3D) multilayer model based on the skin physical structure is developed to investigate the transient thermal response of human skin subject to external heating. The temperature distribution of the skin is …

Interactions Between Structures In The Appalachian And Ouachita Foreland Beneath The Gulf Coastal Plain, Donald Matthew Surles

University of Kentucky Doctoral Dissertations

In Alabama, the Paleozoic Appalachian thrust belt plunges southwest beneath the Mesozoic-Cenozoic Gulf Coastal Plain. In Arkansas, the Paleozoic Ouachita thrust belt plunges southeast beneath the Coastal Plain. The strikes of the exposed thrust belts suggest an intersection beneath the Coastal Plain. Well data and seismic reflection profiles confirm the strike and intersection of the thrust belts, and provide information to determine the structure and general stratigraphy of each thrust belt. In east-central Mississippi, the Appalachian thrust belt curves from the regional northeast trace to westward at the intersection with the southeastern terminus of the Ouachita thrust belt, to northwest …

Enhanced Fire Retardancy Of Vinyl Ester Resins By Combination Of Additives, Grace Chigwada, Charles A. Wilkie

Chemistry Faculty Research and Publications

In pursuit of fire-retardant materials, vinyl ester resins were combined with commercially available fire retardants at lower loadings than that at which they are usually effective when used alone. The thermal stability and flammability of the various combinations of fire retardants were evaluated by thermogravimetric analysis and cone calorimetric analysis. With some combinations, the 50% degradation temperature was improved by about 5-10ºC Different additives affected the flammability to varying extents and some combinations resulted in an enhanced fire retardancy compared to the additives used alone. The combinations that showed the best reductions in the peak heat release rate (PHRR) were …

A Thallium Mediated Route To Σ-Arylalkynyl Complexes Of Bipyridyltricarbonylrhenium(I), Brendan J. Liddle, Sergey V. Lindeman, Daniel L. Reger, James R. Gardinier

Chemistry Faculty Research and Publications

A simple, one-pot preparation of rhenium(I) σ-arylalkynyl complexes is reported using thallium(I) hexafluorophosphate as a halogen abstraction agent. This new route to rhenium σ-alkynyls enjoys higher yields compared to analogous preparations using silver salts by eliminating potential electrochemical degradation pathways.

Hexabenzo[4.4.4]Propellane:  A Helical Molecular Platform For The Construction Of Electroactive Materials, Paromita Debroy, Sergey V. Lindeman, Rajendra Rathore

Chemistry Faculty Research and Publications

Helical hexabenzo[4.4.4]propellane (a relative of hexaphenylethane) and its derivatives are synthesized and their structures are established by X-ray crystallography. Isolation and X-ray crystallographic characterization of a robust trication-radical salt of hexamethoxypropellane derivative confirms that its framework is stable toward oxidative (aliphatic) C−C bond cleavage. It is also demonstrated that propellane can be easily brominated at the 4,4‘-positions of the biphenyl linkages for its usage as a molecular platform for the preparation of electroactive materials.

Practical Synthesis Of Unsymmetrical Tetraarylethylenes And Their Application For The Preparation Of [Triphenylethylene−Spacer−Triphenylethylene] Triads, Moloy Banerjee, Susanna J. Emond, Sergey V. Lindeman, Rajendra Rathore

Chemistry Faculty Research and Publications

We have demonstrated that reactions of diphenylmethyllithium with a variety of substituted benzophenones produces corresponding tertiary alcohols that are easily dehydrated, without any need for purification, to produce various unsymmetrical and symmetrical tetraarylethylenes in excellent yields. The simplicity of the method allows for the preparation of a variety of ethylenic derivatives in multigram (10−50 g) quantities with great ease. The methodology was successfully employed for the preparation of various triphenylethylene (TPE)-based triads (i.e., TPE−spacer−TPE) containing polyphenylene and fluoranyl-based spacers. The ready availability of various substituted tetraarylethylenes allowed us to shed light on the effect of substituents on the oxidation potentials …

Borazans:  Tunable Fluorophores Based On 2-(Pyrazolyl)Aniline Chelates Of Diphenylboron, Brendan J. Liddle, Rosalice M. Silva, Tyler James Morin, Felipe P. Macedo, Ruchi Shukla, Sergey V. Lindeman, James R. Gardinier

Chemistry Faculty Research and Publications

The reaction between 2-pyrazolyl-4-X-anilines, H(pzAn^X), (X = para-OMe (L1), Me (L2), H (L3), Cl (L4), CO₂Et (L5), CF₃ (L6), CN (L7)) and triphenylboron in boiling toluene affords the respective, highly emissive N,N‘-boron chelate complexes, BPh₂(pzAn^X) (X = para-OMe (1), Me (2), H (3), Cl (4), CO₂Et (5), CF₃ (6), CN (7)) in high yield. The …

Preparation Of Chiral Cholestanofluorene And Its Electron-Rich Derivatives For Isolation Of A Stable Cation−Radical Salt, Paromita Debroy, Ruchi Shukla, Sergey V. Lindeman, Rajendra Rathore

Chemistry Faculty Research and Publications

A simple and practical synthesis of a variety of chiral fluorene derivatives is described where a cholestane moiety is attached to the carbon 9 of the fluorene ring system from readily available starting materials. An appropriately substituted fluorene derivative (i.e., R = OMe) forms a highly colored (chiral) cation−radical that can be isolated as robust hexachloroantimonate salt. Interestingly, the simplest cholestanofluorene (i.e., R = H) can also be transformed into a dibromo derivative (i.e., R = Br), a precursor to the (poly)cholestanofluorenes where the cholestane moieties will serve not only as groups that impart chirality but also allow them to …

Electron Transfer Prompted Ejection Of A Tightly Bound K+ From The Ethereal Cavity Of A Hexaarylbenzene-Based Receptor, Ruchi Shukla, Sergey V. Lindeman, Rajendra Rathore

Chemistry Faculty Research and Publications

Synthesis of a pair of rotamers (9u/9s) of a hexaarylbenzene derivative containing six (cofacially arranged) electroactive 2,5-dimethoxytolyl groups is described. The toroidal electronic stabilization due to the circular arrangement of aryl groups in 9u/9s leads to the observation of multiple (reversible) oxidation waves and lowering of their E_ox1 by ∼250 mV relative to model compounds. The binding of K⁺ to symmetrical rotamer 9s was monitored by an electrochemical method and further confirmed by X-ray crystallography.

Conserved Amino Acids In Each Subunit Of The Heteroligomeric Trna M1A58 Mtase From Saccharomyces Cerevisiae Contribute To Trna Binding, Sarah G. Ozanick, Janusz M. Bujnicki, Daniel S. Sem, James T. Anderson

Chemistry Faculty Research and Publications

In Saccharomyces cerevisiae, a two-subunit methyltransferase (Mtase) encoded by the essential genes TRM6 and TRM61 is responsible for the formation of 1-methyladenosine, a modified nucleoside found at position 58 in tRNA that is critical for the stability of . The crystal structure of the homotetrameric m¹A58 tRNA Mtase from Mycobacterium tuberculosis, TrmI, has been solved and was used as a template to build a model of the yeast m¹A58 tRNA Mtase heterotetramer. We altered amino acids in TRM6 and TRM61 that were predicted to be important for the stability of the heteroligomer based on …

Use Of Factor Analysis In Multi‐Electron Spectroelectrochemistry, Michael D. Ryan, Robert L. Keesey

Chemistry Faculty Research and Publications

Spectroelectrochemistry and voltammetry contain both unique and complementary information. For multielectron transfers, information on each electron exchange is only directly accessible in the voltammetric data if the potentials are well separated so that two distinct waves can be observed. If the E°’s are close together, the voltammetric data will contain the sum of the two exchanges which can only be deconvoluted by modeling the system and solving the appropriate equations. On the other hand, the spectroscopic data contains direct information on each electron exchange even when the E°’s are close together. Unfortunately, this information cannot be readily extracted if the …

Xanthene/Benzoxanthene Dyes: Novel Synthetic Metholologies, Applications In Molecular Recognition, Cellular Imaging And The Design Of A Tunable White (Rgb) Light Emitter, Youjun Yang

LSU Doctoral Dissertations

My graduate work has focused on the development of new fluorophore materials towards addressing several interdisciplinary research problems. Selective detection of sialic acid via a boron-amide interaction. Concentration changes of sialic acid can be monitored ratiometrically in the visible region using a boronic acid based chemosensor. The technique shows great promise for the detection of sialic acid, a critical cell surface residue involved in cancer, graft rejection and virulence in certain bacteria. There is no interference from commonly occurring oligosaccharides, aminosugars and most carboxylic acid-containing compounds. Improved synthetic methodology and studies of novel molecular probe architectures. I have developed a …

Backward Stochastic Navier-Stokes Equations In Two Dimensions, Hong Yin

LSU Doctoral Dissertations

There are two parts in this dissertation. The backward stochastic Lorenz system is studied in the first part. Suitable a priori estimates for adapted solutions of the backward stochastic Lorenz system are obtained. The existence and uniqueness of solutions is shown by the use of suitable truncations and approximations. The continuity of the adapted solutions with respect to the terminal data is also established. The backward stochastic Navier-Stokes equations (BSNSEs, for short) corresponding to incompressible fluid flow in a bounded domain $G$ are studied in the second part. Suitable a priori estimates for adapted solutions of the BSNSEs are obtained …

Computing And Analyzing Gravitational Radiation In Black Hole Simulations Using A New Multi-Block Approach To Numerical Relativity, Ernst Nils Dorband

LSU Doctoral Dissertations

Numerical simulations of Kerr black holes are presented and the excitation of quasinormal modes is studied in detail. Issues concerning the extraction of gravitational waves from numerical space-times and analyzing them in a systematic way are discussed. A new multi-block infrastructure for solving first order symmetric hyperbolic time dependent partial differential equations is developed and implemented in a way that stability is guaranteed for arbitrary high order accurate numerical schemes. Multi-block methods make use of several coordinate patches to cover a computational domain. This provides efficient, flexible and very accurate numerical schemes. Using this code, three dimensional simulations of perturbed …

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 …

Development Of Test Paradigms For Operant Conditioning Of Wild Norway Rats, Susan M. Jojola, Patrick W. Burke, Gary W. Witmer, Dale L. Nolte

United States Department of Agriculture Wildlife Services: Staff Publications

Many eradication efforts to remove rats (Rattus spp.) from islands have been successful. Eradications are expensive and labor-intensive which makes early detection of, and response to, reinvasion by rats critical. A better understanding of rat behavior could facilitate early detection and rapid response to intercept invaders, such as with trap placement and design, and toxic bait presentation and dispersal. This was a methods development study of test paradigms to operantly condition wild rats to run on an activity wheel and to press a lever for use in future behavior studies. Operant conditioning is the process of associating specific responses …

An Assessment Of Impediments To Low-Impact Development In The Virginia Portion Of The Chesapeake Bay Watershed, Rebecca V'Lent Lassiter

Theses and Dissertations

Stormwater runoff from urban and urbanizing areas poses a serious threat to water quality, and unless managed properly will impede efforts to restore the Chesapeake Bay.Water quantity, as well as quality, must be considered, and Low Impact Development(LID) is an innovative stormwater management approach that addresses both. LID seeks to mimic a site's predevelopment hydrologic regime by retaining and treating stormwater at the lot level using small, cost-effective landscape features.The purpose for this study was to identify and rank impediments to the implementation of LID in the Virginia portion of the Chesapeake Bay watershed. This was accomplished by going to …

Repurposing A Roomba: Evaluating And Training Behavior In A Simple Agent, Donald Samuel Abbott-Mccune

Theses and Dissertations

Recent attempts to reprogram a Roomba to be used as a simple agent have led to interesting behavior. Observation has shown that the behavior of the Roomba is not only dependent on the precepts of the Roomba, but also relies heavily on the uncontrollable environmental conditions that the Roomba is placed in. Ultimately this makes the Roomba a great platform to test and teach aspects of artificial intelligence. This paper will show how most of the tested environmental conditions are mitigated by a learning agent that will adjust behavior dependent on the precepts that are received.

Book Review: Conquest In Cyberspace: National Security And Information Warfare, Gary C. Kessler

Publications

This document is Dr. Kessler's review of Conquest in Cyberspace: National Security and Information Warfare, by Martin C. Libicki. Cambridge University Press, 2007. ISBN 978-0-521-69214-4