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Homogenization And Field Concentrations In Heterogeneous Media, Robert Lipton

Faculty Publications

A multiscale characterization of the field concentrations inside composite and polycrystalline media is developed. We focus on gradient fields associated with the intensive quantities given by the temperature and the electric potential. In the linear regime these quantities are modeled by the solution of a second order elliptic partial differential equation with oscillatory coefficients. The characteristic length scale of the heterogeneity relative to the sample size is denoted by ε and the intensive quantity is denoted by u ε. Field concentrations are measured using the L p norm of the gradient field ||∇u ε||L p(D) for 2 ≤ p < ∞. The analysis focuses on the case when 0 < ε ≪ 1. Explicit lower bounds on lim inf ε→0 are developed. These bounds provide a way to rigorously assess field concentrations generated by the microgeometry without having to compute the actual field u ε. © 2006 Society for Industrial and Applied Mathematics.

Optimization Of Composite Structures Subject To Local Stress Constraints, Robert Lipton, Michael Stuebner

Faculty Publications

An extension of current methodologies is introduced for optimization of graded microstructure subject to local stress criteria. The method is based on new multiscale stress criteria given by macrostress modulation functions. The modulation functions quantify the intensity of local stress fluctuations at the scale of the microstructure due to the imposed macroscopic stress. The methodology is illustrated for long cylindrical shafts reinforced with stiff cylindrical elastic fibers with generators parallel to the shaft. Examples are presented for shaft cross sections that possess reentrant corners typically seen in lap joints and junctions of struts. It is shown that the computational methodology …

Estradiol Interactions With Dopamine Antagonists In Mares: Prolactin Secretion And Reproductive Traits, K. K. Kelley, D. L. Thompson, W. A. Storer, P. B. Mitcham, R. M. Gilley, P. J. Burns

Faculty Publications

Two experiments studied the effects of pretreatment with estradiol benzoate before treatment with a dopamine antagonist on prolactin secretion and reproductive traits in mares during (1) the seasonal anovulatory period and (2) the normal breeding season. Experiment 1 was performed in winter with 17 mares selected for low follicular activity. Nine mares received estradiol benzoate injections every other day for a total of 10 injections; 8 mares received similar injections of vehicle. Ten days after onset of injections, all mares were placed on daily injections of sulpiride (250 mg) for 35 days or until ovulation. Plasma prolactin concentrations were higher …

An Organic White Light-Emitting Fluorophore, Youjun Yang, Mark Lowry, Corin M. Schowalter, Sayo O. Fakayode, Jorge O. Escobedo, Xiangyang Xu, Huating Zhang, Timothy J. Jensen, Frank R. Fronczek, Isiah M. Warner, Robert M. Strongin

Faculty Publications

The synthesis of new benzo[a]- and [b]xanthene dye frameworks is described. A unique benzo[a]xanthene, seminaphtho[a]fluorone (SNAFR-1), is studied in a variety of media. The optimization of solution parameters and excitation wavelengths allows SNAFR-1 to display red, green, and blue emission bands of approximately equal intensities and also to produce white light. Ratiometric red (anion) and green (neutral) emissions are observed upon varying solution pH. A pH-independent violet-blue emission band is due to the addition of nucleophiles to the benzylic carbon of SNAFR-1. © 2006 American Chemical Society.

F06rs Sgb No. 18 (No More Sio), Alsfeld

Student Senate Enrolled Legislation

No abstract provided.

Louisiana Agriculture Fall, 2006, Lsu Agcenter

Louisiana Agriculture

No abstract provided.

Louisiana Survey 2006 (Fall), Lsu Reilly Center For Media & Public Affairs

Reilly Center Louisiana Surveys

The fall 2006 Louisiana Survey noted the beginning of a return to a "new normal" in public opinion following the devastation of hurricanes Katrina and Rita. The number of residents who reported optimism that the state was heading in the right direction increased from 2005, but still did not equal pre-hurricane levels. In addition, the 2006 LA Survey explored:

• the re-emergence of dominance for pre-Katrina concerns such as education, healthcare, and crime in the state
• an increase in number of residents noting climate change as their number one concern for the future of the state
• disconcerting trends on perceptions of …

Stereochemical And Regiochemical Trends In The Selective Detection Of Saccharides, Shan Jiang, Jorge O. Escobedo, Kyu Kwang Kim, Onur Alptürk, George K. Samoei, Sayo O. Fakayode, Isiah M. Warner, Oleksandr Rusin, Robert M. Strongin

Faculty Publications

Several discreet sugar-boronate complexes exist in solution. This is due to the complex equilibria between isomeric species of even the simplest monosaccharides. In the current investigation, we determine the regio- and stereochemical features of the various equilibrating sugar isomers that induce signal transduction in boronic acid chemosensors such as 1 as well as 2 and 3. We present a unique example of a chemosensor (1) that is selective for ribose, adenosine, nucleotides, nucleosides, and congeners. As a result of this study, we are able to predict and achieve selective fluorescence and colorimetric responses to specific disaccharides as a consequence of …

Mesostructured Silica Chemically Doped With RuIi As A Superior Optical Oxygen Sensor, Bingfu Lei, Bin Li, Haoran Zhang, Shaozhe Lu, Zhuhong Zheng, Wenlian Li, Yue Wang

Faculty Publications

Novel oxygen sensors consisting of a [Ru(bpy)2phen]2+ (bpy: 2,2′-bipyridyl, phen: phenathroline) portion covalently grafted to a mesostructured silica-based network are prepared in situ via a sol-gel approach with the help of cetyltrimethylammonium-bromide (CTAB) surfactant. 1,10-Phenanthroline covalently grafted to 3-(triethoxysilyl)propyl isocyanate is used as not only the sol-gel precursor but also as the second ligand of the Ru(bpy)2d2 · 2H2O complex to prepare the sol-gel-derived mesostructured silicates for an oxygen sensor. For comparison purposes, the oxygen sensors in which [Ru(bpy)2phen]Q2 is conventionally physically incorporated into the matrix are also prepared. Elemental analysis, NMR, Fourier transform IR, UV-vis electronic absorption, luminescence-intensity quenching …

Post-Thaw Amendment Of Cryopreserved Sperm For Use In Artificial Insemination Of A Viviparous Fish, The Green Swordtail Xiphophorus Helleri, Qiaoxiang Dong, Changjiang Huang, Terrence R. Tiersch

Faculty Publications

Sperm cryopreservation protocols have been developed for live-bearers such as the green swordtail Xiphophorus helleri and the platyfish Xiphophorus couchianus. Despite the high post-thaw motility (∼ 75%) obtained in both species, the requirements of sperm storage within the female reproductive tract coupled with the process of internal fertilization place functional demands upon cryopreserved sperm samples far beyond those of oviparous species. The purpose of this study was to facilitate the artificial insemination process with cryopreserved sperm of X. helleri through evaluation of parameters related to sperm quality after thawing. Specifically, this study evaluated the effects on motility for fresh and …

Petroleum Geologist's Award To Novelist Crichton Is Inappropriate, Julie Brigham-Grete, Scott Anderson, John Clague, Julia Cole, Peter Doran, Alan Gillespie, Eric Grimm, Peggy Guccione, Konrad Hijghen, Stephen Jackson, Timothy Jull, Steven Leavitt, Rolfe Mandel, Joseph Ortiz, Donald Rodbell, Charlie Schweger, Alison Smith, Bonnie Styles

Faculty Publications

No abstract provided.

Annotations, Cwbr_Editor

Civil War Book Review

No abstract provided.

Exposure Of Neonates To Respiratory Syncytial Virus Is Critical In Determining Subsequent Airway Response In Adults, Dahui You, David Becnel, Kai Wang, Michael Ripple, Melissa Daly, Stephania A. Cormier

Faculty Publications

Background: Respiratory syncytial virus (RSV) is the most common cause of acute bronchiolitis in infants and the elderly. Furthermore, epidemiological data suggest that RSV infection during infancy is a potent trigger of subsequent wheeze and asthma development. However, the mechanism by which RSV contributes to asthma is complex and remains largely unknown. A recent study indicates that the age of initial RSV infection is a key factor in determining airway response to RSV rechallenge. We hypothesized that severe RSV infection during neonatal development significantly alters lung structure and the pulmonary immune micro-environment; and thus, neonatal RSV infection is crucial in …

A Chemomechanical Polymer That Functions In Blood Plasma With High Glucose Selectivity, George K. Samoei, Weihua Wang, Jorge O. Escobedo, Xiangyang Xu, Hans Jörg Schneider, Robert L. Cook, Robert M. Strongin

Faculty Publications

(Figure Presented) See the shrink: Systematic modification of poly(methyl methacrylate) leads to a chemomechanical polymer that selectively contracts in the presence of glucose at physiological levels in human blood plasma. The polymer also exhibits good reversibility allowing continuous expansion-contraction cycles. © 2006 Wiley-VCH Verlag GmbH & Co. KGaA.

Thermalkalibacillus Uzonensis Gen. Nov. Sp. Nov, A Novel Aerobic Alkali-Tolerant Thermophilic Bacterium Isolated From A Hot Spring In Uzon Caldera, Kamchatka, Weidong Zhao, Carolyn Weber, Chuanlun L. Zhang, Christopher S. Romanek, Gary M. King, Gary Mills, Tatyana Sokolova, Juergen Wiegel

Faculty Publications

A novel thermophilic, alkali-tolerant, and CO-tolerant strain JW/WZ-YB58T was isolated from green mat samples obtained from the Zarvarzin II hot spring in the Uzon Caldera, Kamchatka (Far East Russia). Cells were Gram-type and Gram stain-positive, strictly aerobic, 0.7-0.8 μm in width and 5.5-12 μm in length and produced terminal spherical spores of 1.2-1.6 μm in diameter with the mother cell swelling around 2 μm in diameter (drumstick-type morphology). Cells grew optimally at pH25°C 8.2-8.4 and temperature 50-52°C and tolerated maximally 6% (w/v) NaCl. They were strict heterotrophs and could not use either CO or CO2 (both with or without H2) …

Reca And Rada Proteins Of Brucella Abortus Do Not Perform Overlapping Protective Dna Repair Functions Following Oxidative Burst, Christelle M. Roux, Natha J. Booth, Bryan H. Bellaire, Jason M. Gee, R. Martin Roop, Michael E. Kovach, Renée M. Tsolis, Philip H. Elzer, Don G. Ennis

Faculty Publications

Very little is known about the role of DNA repair networks in Brucella abortus and its role in pathogenesis. We investigated the roles of RecA protein, DNA repair, and SOS regulation in B. abortus. While recA mutants in most bacterial species are hypersensitive to UV damage, surprisingly a B. abortus recA null mutant conferred only modest sensitivity. We considered the presence of a second RecA protein to account for this modest UV sensitivity. Analyses of the Brucella spp. genomes and our molecular studies documented the presence of only one recA gene, suggesting a RecA-independent repair process. Searches of the available …

Louisiana Agriculture Summer, 2006, Lsu Agcenter

Louisiana Agriculture

No abstract provided.

Does The Third Law Of Thermodynamics Hold In The Quantum Regime?, R. F. O'Connell

Faculty Publications

The first in a long series of papers by John T. Lewis, in collaboration with G. W. Ford and the present author, considered the problem of the most general coupling of a quantum particle to a linear passive heat bath, in the course of which they derived an exact formula for the free energy of an oscillator coupled to a heat bath in thermal equilibrium at temperature $T$. This formula, and its later extension to three dimensions to incorporate a magnetic field, has proved to be invaluable in analyzing problems in quantum thermodynamics. Here, we address the question raised in …

Lanthanide Complexes As Fluorescent Indicators For Neutral Sugars And Cancer Biomarkers, Onur Alptürk, Oleksandr Rusin, Sayo O. Fakayode, Weihua Wang, Jorge O. Escobedo, Isiah M. Warner, William E. Crowe, Vladimir Král, Jeff M. Pruet, Robert M. Strongin

Faculty Publications

Simple water-soluble lanthanum and europium complexes are effective at detecting neutral sugars as well as glycolipids and phospholipids. In solutions at physiologically relevant pH the fluorescent lanthanum complex binds neutral sugars with apparent binding constants comparable to those of arylboronic acids. Interference from commonly occurring anions is minimal. The europium complex detects sialic acid-containing gangliosides at pH 7.0 over an asialoganglioside. This selectivity is attributed, in large part, to the cooperative complexation of the oligosaccharide and sialic acid residues to the metal center, based on analogous prior studies. In MeOH, lysophosphatidic acid (LPA), a biomarker for several pathological conditions including …

Molecular Fluorescence, Phosphorescence, And Chemiluminescence Spectrometry, Kristin A. Fletcher, Sayo O. Fakayode, Mark Lowry, Sheryl A. Tucker, Sharon L. Neal, Irene W. Kimaru, Matthew E. Mccarroll, Gabor Patonay, Philip B. Oldham, Oleksandr Rusin, Robert M. Strongin, Isiah M. Warner

Faculty Publications

No abstract provided.