Digital Commons Network^™

The Relative Influence Of Metal Ion Binding Sites In The I-Like Domain And The Interface With The Hybrid Domain On Rolling And Firm Adhesion By Integrin Α4Β7, Jian Feng Chen, Junichi Takagi, Can Xie, Tsan Xiao, Bing Hao Luo, Timothy A. Springer

Faculty Publications

We examined the effect of conformational change at the β7 I-Iike/hybrid domain interface on regulating the transition between rolling and firm adhesion by integrin α4β7. An N-glycosylation site was introduced into the I-like/hybrid domain interface to act as a wedge and to stabilize the open conformation of this interface and hence the open conformation of the α4β7 headpiece. Wild-type α4β7 mediates rolling adhesion in Ca2+ and Ca2+/Mg2+ but firm adhesion in Mg2+ and Mn2+. Stabilizing the open headpiece resulted in firm adhesion in all divalent cations. The interaction between metal binding sites in the I-like domain and the interface with …

The Saccharomyces Cerevisiae High Mobility Group Box Protein Hmo1 Contains Two Functional Dna Binding Domains, Edwin Kamau, Kevin T. Bauerle, Anne Grove

Faculty Publications

High mobility group box (HMGB) proteins are architectural proteins whose HMG DNA binding domains confer significant preference for distorted DNA, such as 4-way junctions. HMO1 is one of 10 Saccharomyces cerevisiae HMGB proteins, and it is required for normal growth and plasmid maintenance and for regulating the susceptibility of yeast chromatin to nuclease. Using electrophoretic mobility shift assays, we have shown here that HMO1 binds 26-bp duplex DNA with K d = 39.6 ± 5.0 nM and that its divergent box A domain participates in DNA interactions, albeit with low affinity. HMO1 has only modest preference for DNA with altered …

Studies Of High-K Isomers At Triumf-Isac, M. B. Smith, P. M. Walker, R. S. Chakrawarthy, R. A.E. Austin, G. C. Ball, J. J. Carroll, E. Cunningham, P. Finlay, P. E. Garrett, G. F. Grinyer, G. Hackman, B. Hyland, K. Koopmans, W. D. Kulp, J. R. Leslie, A. A. Phillips, R. Propri, P. H. Regan, F. Sarazin, M. A. Schumaker, H. C. Scraggs, T. Shizuma, C. E. Svensson, J. Von Schwarzenberg, J. C. Waddington, D. Ward, J. L. Wood, B. Washbrook, E. F. Zganjar

Faculty Publications

The properties of high-K isomers have been investigated by measuring γ rays from a source of the 31-year 178Hfm2 isomer and from the decay of implanted 178,179Lu beams. Low-intensity transitions have been identified in the decay of 178Hfm2, demonstrating a consistent extension of K-hindrance systematics to higher multipolarities, and elucidating the spin-dependence of the mixing between the two Kπ = 8- bands. A search is underway for new isomers in 178,179Lu and the preliminary results of the analysis are reported. © 2004 Elsevier B.V. All rights reserved.

Quantum Zeno And Anti-Zeno Effects: An Exact Model, T. C. Dorlas, R. F. O'Connell

Faculty Publications

Recent studies suggest that both the quantum Zeno (increase of the natural lifetime of an unstable quantum state by repeated measurements) and anti-Zeno (decrease of the natural lifetime) effects can be made manifest in the same system by simply changing the dissipative decay rate associated with the environment. Here, we present a model which incorporates the effect of the environment in an exact manner leading to a confirmation of this expectation.

Toward A Systems Approach To Understanding Plant Cell Walls, Chris Somerville, Stefan Bauer, Ginger Brininstool, Michelle Facette, Thorsten Hamann, Jennifer Milne, Erin Osborne, Alex Paredez, Staffan Persson, Ted Raab, Sonja Vorwerk, Heather Youngs

Faculty Publications

One of the defining features of plants is a body plan based on the physical properties of cell walls. Structural analyses of the polysaccharide components, combined with high-resolution imaging, have provided the basis for much of the current understanding of cell walls. The application of genetic methods has begun to provide new insights into how walls are made, how they are controlled, and how they function. However, progress in integrating biophysical, developmental, and genetic information into a useful model will require a system-based approach.

Global Asymptotic Controllability Implies Input-To-State Stabilization, Michael Malisoff, Ludovic Rifford, Eduardo Sontag

Faculty Publications

The main problem addressed in this paper is the design of feedbacks for globally asymptotically controllable (GAC) control affine systems that render the closed-loop systems input-to-state stable (ISS) with respect to actuator errors. Extensions for fully nonlinear GAC systems with actuator errors are also discussed. Our controllers have the property that they tolerate small observation noise as well.

Loop Quantum Gravity Effects On Inflation And The Cmb, Shinji Tsujikawa, Parampreet Singh, Roy Maartens

Faculty Publications

In loop quantum cosmology, the universe avoids a big bang singularity and undergoes an early and short super-inflation phase. During super-inflation, non-perturbative quantum corrections to the dynamics drive an inflaton field up its potential hill, thus setting the initial conditions for standard inflation. We show that this effect can raise the inflaton high enough to achieve sufficient e-foldings in the standard inflation era. We analyse the cosmological perturbations generated when slow-roll is violated after super-inflation and show that loop quantum effects can in principle leave an indirect signature on the largest scales in the CMB, with some loss of power …

Caster - A Scintillator-Based Black Hole Finder Probe, M. L. Mcconnell, M. L. Cherry, T. G. Guzik, R. M. Kippen, J. M. Ryan, J. M. Macri, R. S. Miller, W. S. Paciesas, B. E. Schaefer, J. G. Stacy, J. P. Wefel, W. T. Vestrand

Faculty Publications

The primary scientific mission of the Black Hole Finder Probe (BHFP), part of the NASA Beyond Einstein program, is to survey the local Universe for black holes over a wide range of mass and accretion rate. One approach to such a survey is a hard X-ray coded-aperture imaging mission operating in the 10-600 keV energy band, a spectral range that is considered to be especially useful in the detection of black hole sources. The development of new inorganic scintillator materials provides improved performance (for example, with regards to energy resolution and timing) that is well suited to the BHFP science …

Mega: The Next Generation Medium Energy Gamma-Ray Telescope, J. M. Ryan, R. Andritschke, P. Bloser, J. Cravens, M. Cherry, G. Dicocco, T. G. Guzik, D. H. Hartmann, S. Hunter, G. Kanbach, R. M. Kippen, J. Kurfess, J. R. Macri, M. L. Mcconnell, R. S. Miller, W. Paciesas, B. Phlips, V. Regiero, J. G. Stacy, M. Strickman, W. T. Vestrand, J. P. Wefel, E. Wulf, A. Zoglauer, A. D. Zych

Faculty Publications

The MEGA mission would enable a sensitive all-sky survey of the medium-energy γ-ray sky (0.3-50 MeV). This mission will bridge the huge sensitivity gap between the COMPTEL and OSSE experiments on the Compton Gamma Ray Observatory, the SPI and IBIS instruments on INTEGRAL and the visionary ACT mission. It will, among other things, serve to compile a much larger catalog of sources in this energy range, perform far deeper searches for supernovae, better measure the galactic continuum emission as well as identify the components of the cosmic diffuse emission. The large field of view will allow MEGA to continuously monitor …

Genome Sequence Of Silicibacter Pomeroyi Reveals Adaptations To The Marine Environment, Mary Ann Moran, Alison Buchan, José M. González, John F. Heidelberg, William B. Whitman, Ronald P. Klene, James R. Henriksen, Gary M. King, Robert Belas, Clay Fuqua, Lauren Brinkac, Matt Lewis, Shivani Johri, Bruce Weaver, Grace Pai, Jonathan A. Elsen, Elisha Rahe, Wade M. Sheldon, Wenying Ye, Todd R. Miller, Jane Carlton, David A. Rasko, Ian T. Paulsen, Qinghu Ren, Sean C. Daugherty, Ribert T. Deboy, Robert J. Dodson, A. Scott Durkin, Ramana Madupu, William C. Nelson, Steven A. Sullivan, M. J. Rosovitz, Daniel H. Haft

Faculty Publications

Since the recognition of prokaryotes as essential components of the oceanic food web1, bacterioplankton have been acknowledged as catalysts of most major biogeochemical processes in the sea. Studying heterotrophic bacterioplankton has been challenging, however, as most major clades have never been cultured2 or have only been grown to low densities in sea water3,4. Here we describe the genome sequence of Silicibacter pomeroyi, a member of the marine Roseobacter clade (Fig. 1), the relatives of which comprise ∼10-20% of coastal and oceanic mixed-layer bacterioplankton2,5,6,7. This first genome sequence from any major heterotrophic clade consists of a chromosome (4,109,442 base pairs) and …

Realistic Clocks, Universal Decoherence, And The Black Hole Information Paradox, Rodolfo Gambini, Rafael A. Porto, Jorge Pullin

Faculty Publications

Quantum mechanics was formulated on the basis of the existence of an ideal classical clock external to the system. The rate of the universal loss of unitarity was estimated using optimal realistic clocks. The loss of unitarity is universal thus affecting all physical phenomena. It is observed that the rate is enough to eliminate the black hole information puzzle.

Faculty Senate Resolution 05-05, Louisiana State University And Agricultural & Mechanical College

LSU Faculty Senate Publications

Faculty Senate Resolution thanking and commending Professor McGehee, and endorsing the creation of the McGehee Award, adopted on December 8, 2004.

[Untitled], Amanda Lyn Gustavson

Honors Theses

No abstract provided.

Hucr, A Novel Uric Acid-Responsive Member Of The Marr Family Of Transcriptional Regulators From Deinococcus Radiodurans, Steven P. Wilkinson, Anne Grove

Faculty Publications

The MarR family of transcriptional regulators comprises a subset of winged helix DNA-binding proteins and includes numerous members that function in environmental surveillance of aromatic compounds. We describe the characterization of HucR, a novel MarR homolog from Deinococcus radiodurans that demonstrates phenolic sensing capabilities. HucR binds as a homodimer to a single site within its promoter/operator region with Kd = 0.29 ± 0.02 nM. The HucR binding site contains a pseudopalindromic sequence, composed of 8-bp half-sites separated by 2 bp. The location of the HucR binding site in the intergenic region between hucR and a putative uricase suggests a mechanism …

Characterization Of Probability Measures Through The Canonically Associated Interacting Fock Spaces, Luigi Accardi, Hui Hsiung Kuo, Aurel Stan

Faculty Publications

We continue our program of coding the whole information of a probability measure into a set of commutation relations canonically associated to it by presenting some characterization theorems for the symmetry and factorizability of a probability measure on ℝd in terms of the canonically associated interacting creation, annihilation and number operators.

Vortices In Spatially Inhomogeneous Superfluids, Daniel E. Sheehy, Leo Radzihovsky

Faculty Publications

Vortices in a radially inhomogeneous superfluid, as realized by a trapped degenerate Bose gas in a uniaxially symmetric potential was analyzed. It was found that in contrast to a homogeneous superfluid, an off-axis vortex corresponds to an anisotropic superflow whose profile strongly depends on the distance to the trap axis. The minimum-energy vortex density was computed in the complementary regime of a finite prescribed rotation, showing that in the rapid-rotation limit it is extremely uniform, despite a strongly inhomogeneous Thomas-Fermi condensate density. It was shown that one striking consequence of the inhomogeneous vortex distribution is an azimuthally directed, radially shearing …

No Black Hole Information Puzzle In A Relational Universe, Rodolfo Gambini, Rafael A. Porto, Jorge Pullin

Faculty Publications

The introduction of a relational time in quantum gravity naturally implies that pure quantum states evolve into mixed quantum states. We show, using a recently proposed concrete implementation, that the rate at which pure states naturally evolve into mixed ones is faster than that due to collapsing into a black hole that later evaporates. This is rather remarkable since the fundamental mechanism for decoherence is usually very weak. Therefore the "black hole information puzzle" is rendered de-facto unobservable. © World Scientific Publishing Company.

Erratum: Holomorphic H-Spherical Distribution Vectors In Principal Series Representations (Inventiones Mathematicae) Doi: 10.1007/S00222-004-0376-1, Simon Gindikin, Bernhard Krötz, Gestur Ólafsson

Faculty Publications

No abstract provided.

Coordinate Time Dependence In Quantum Gravity, Martin Bojowald, Parampreet Singh, Aureliano Skirzewski

Faculty Publications

The intuitive classical space-time picture breaks down in quantum gravity, which makes a comparison and the development of semiclassical techniques quite complicated. Using ingredients of the group averaging method to solve constraints one can nevertheless introduce a classical coordinate time into the quantum theory, and use it to investigate the way a semiclassical continuous description emerges from discrete quantum evolution. Applying this technique to test effective classical equations of loop cosmology and their implications for inflation and bounces, we show that the effective semiclassical theory is in good agreement with the quantum description even at short scales.

The Massive Neutron Star Or Low-Mass Black Hole In 2s 0921-630, T. Shahbaz, J. Casares, C. A. Watson, P. A. Charles, R. I. Hynes, S. C. Shih, D. Steeghs

Faculty Publications

We report on the optical spectroscopy of the eclipsing halo low-mass X-ray binary 2S 0921 - 630, which reveals the absorption-line radial velocity curve of the K0 III secondary star with a semiamplitude K2 = 92.89 ± 3.84 km s-1, a systemic velocity γ = 34.9 ± 3. 3 km s-1, and an orbital period Porb of 9.0035 ± 0.0029 days (1 σ). Given the quality of the data, we find no evidence for the effects of X-ray irradiation. Using the previously determined rotational broadening of the mass donor and applying conservative limits on the orbital inclination, we constrain the …

Fundamental Decoherence From Relational Time In Discrete Quantum Gravity: Galilean Covariance, Rodolfo Gambini, Rafael A. Porto, Jorge Pullin

Faculty Publications

We have recently argued that if one introduces a relational time in quantum mechanics and quantum gravity, the resulting quantum theory is such that pure states evolve into mixed states. The rate at which states decohere depends on the energy of the states. There is therefore the question of how this can be reconciled with Galilean invariance. More generally, since the relational description is based on objects that are not Dirac observables, the issue of covariance is of importance in the formalism as a whole. In this note we work out an explicit example of a totally constrained, generally covariant …

Dominant-Negative Creb Inhibits Heparanase Functionality And Melanoma Cell Invasion, Rebecca Aucoin, Jane Reiland, Madhuchhanda Roy, Dario Marchetti

Faculty Publications

Heparanase (HPSE-1) is an endo-β-D-glucuronidase involved in the degradation of cell-surface/extracellular matrix heparan sulfate (HS) in normal and neoplastic tissues. HPSE-1 represents the first example of purification and cloning of a mammalian HS-degradative enzyme. Elevated HPSE-1 levels are known to be associated with metastatic cancers, directly implicating HPSE-1 in metastatic events. The purpose of this study was to determine the role of cAMP response element-binding protein (CREB) in modulating HPSE-1-mediated effects on human melanoma cell invasion. Highly invasive, brain-metastatic melanoma cells (70W) were transfected with the dominant-negative CREB (KCREB) and subsequently analyzed for changes in their HPSE-1 content, functionality, and …

The Malic Enzyme Is Required For Optimal Photoautotrophic Growth Of Synechocystis Sp. Strain Pcc 6803 Under Continuous Light But Not Under A Diurnal Light Regimen, Terry M. Bricker, Shulu Zhang, Susan M. Laborde, Paul R. Mayer, Laurie K. Frankel, James V. Moroney

Faculty Publications

A mutation was recovered in the slr0721 gene, which encodes the decarboxylating NADP+-dependent malic enzyme in the cyanobacterium Synechocystis sp. strain PCC 6803, yielding the mutant 3WEZ. Under continuous light, 3WEZ exhibits poor photoautotrophic growth while growing photoheterotrophically on glucose at rates nearly indistinguishable from wild-type rates. Interestingly, under diurnal light conditions (12 h of light and 12 h of dark), normal photoautotrophic growth of the mutant is completely restored.

Fragile Fiber3, An Arabidopsis Gene Encoding A Type Ii Inositol Polyphosphate 5-Phosphatase, Is Required For Secondary Wall Synthesis And Actin Organization In Fiber Cells, Ruiqin Zhong, David H. Burk, W. Herbert Morrison, Zheng Hua Ye

Faculty Publications

Type II inositol polyphosphate 5-phosphatases (5PTases) in yeast and animals have been known to regulate the level of phosphoinositides and thereby influence various cellular activities, such as vesicle trafficking and actin organization. In plants, little is known about the phosphatases involved in hydrolysis of phosphoinositides, and roles of type II 5PTases in plant cellular functions have not yet been characterized. In this study, we demonstrate that the FRAGILE FIBER3 (FRA3) gene of Arabidopsis thaliana, which encodes a type II 5PTase, plays an essential role in the secondary wall synthesis in fiber cells and xylem vessels. The fra3 mutations caused a …

Ultraviolet Extinction Properties In The Milky Way, Lynne A. Valencic, Geoffrey C. Clayton, Karl D. Gordon

Faculty Publications

We have assembled a homogeneous database of 417 ultraviolet (UV) extinction curves for reddened sight lines having International Ultraviolet Explorer spectra. We have combined these with optical and Two Micron All Sky Survey photometry, allowing estimates of the ratio of total-to-selective extinction, RV, for the entire sample. Fitzpatrick-Massa (FM) parameters have also been found for the entire sample. This is the largest study of parameterized UV extinction curves yet published, and it covers a wide range of environments, from dense molecular clouds to the diffuse interstellar medium, with extinctions AV ranging from 0.50 to 4.80. It is the first to …

Seismic Isolation And Suspension Systems For Advanced Ligo, N. A. Robertson, B. Abbott, R. Abbott, R. Adhikari, G. Allen, H. Armandula, S. Aston, A. Baglino, M. Barton, B. Bland, R. Bork, J. Bogenstahl, G. Cagnoli, C. Campbell, C. A. Cantley, K. Carter, D. Cook, D. Coyne, D. Crooks, E. Daw, D. Debra, E. Elliffe, J. Faludi, P. Fritschel, A. Ganguli, J. Giaime, S. Gossler, A. Grant, J. Greenhalgh, M. Hammond, J. Hanson, C. Hardham, G. Harry

Faculty Publications

To meet the overall isolation and alignment requirements for the optics in Advanced LIGO, the planned upgrade to LIGO, the US laser interferometric gravitational wave observatory, we are developing three sub-systems: a hydraulic external pre-isolator for low frequency alignment and control, a two-stage active isolation platform designed to give a factor of ∼1000 attenuation at 10 Hz, and a multiple pendulum suspension system that provides passive isolation above a few hertz. The hydraulic stage uses laminar-flow quiet hydraulic actuators with millimeter range, and provides isolation and alignment for the optics payload below 10 Hz, including correction for measured Earth tides …

On Shioda-Inose Structures Of One-Parameter Families Of K3 Surfaces, Ling Long

Faculty Publications

We develop an algorithm to determine a one-parameter family of elliptic curves associated to a one-parameter family of K3 surfaces with generic Picard number 19 by a Shioda-Inose structure. The family of elliptic curves is determined up to an isomorphism and an isogeny. An application to a generalized congruence number problem is also discussed. © 2004 Elsevier Inc. All rights reserved.

Herpes Simplex Virus Type 1 Glycoprotein K And The Ul20 Protein Are Interdependent For Intracellular Trafficking And Trans-Golgi Network Localization, Timothy P. Foster, Jeffrey M. Melancon, Trisha L. Olivier, Konstantin G. Kousoulas

Faculty Publications

Final envelopment of the cytoplasmic herpes simplex virus Hype 1 (HSV-1) nucleocapsid is thought to occur by budding into trans-Golgi network (TGN)-derived membranes. The highly membrane-associated proteins UL20p and glycoprotein K (gK) are required for cytoplasmic envelopment at the TGN and virion transport from the TGN to extracellular spaces. Furthermore, the UL20 protein is required for intracellular transport and cell surface expression of gK. Independently expressed gK or UL20p via transient expression in Vero cells failed to be transported from the endoplasmic reticulum (ER). Similarly, infection of Vero cells with either gK-null or UL20-null viruses resulted in ER entrapment of …

The Bloody Crucible Of Courage: Fighting Methods And Combat Experience Of The Civil War, Major Charles R. Bowery

Civil War Book Review

Tactical Treatise

Author challenges views of combat

Signatures Of Citizenship: Petitioning, Antislavery, And Women's Political Identity, Beverly Wilson Palmer

Civil War Book Review

Exercising their Rights

Study reveals women's roles in reform