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nip, a Symbiotic Medicago truncatula Mutant that Forms Root Nodules with Aberrant Infection Threads and Plant Defense-Like Response (open access)

nip, a Symbiotic Medicago truncatula Mutant that Forms Root Nodules with Aberrant Infection Threads and Plant Defense-Like Response

Article on nip, a symbiotic Medicago truncatula mutant that forms root nodules with aberrant infection threads and plant defense-like response.
Date: November 2004
Creator: Veereshlingam, Harita; Haynes, Janine G.; Penmetsa, R. Varma; Cook, Douglas R.; Sherrier, D. Janine & Dickstein, Rebecca
System: The UNT Digital Library
Electronic and Transport Properties of Artificial Gold Chains (open access)

Electronic and Transport Properties of Artificial Gold Chains

Article on electronic and transport properties of artificial gold chains.
Date: August 27, 2004
Creator: Calzolari, Arrigo; Cavazzoni, Carlo & Buongiorno Nardelli, Marco
System: The UNT Digital Library
Ab Initio Studies of Polarization and Piezoelectricity in Vinylidene Fluoride and BN-Based Polymers (open access)

Ab Initio Studies of Polarization and Piezoelectricity in Vinylidene Fluoride and BN-Based Polymers

Article on ab initio studies of polarization and piezoelectricity in vinylidene fluoride and BN-based polymers.
Date: 2004
Creator: Nakhmanson, Serge M.; Buongiorno Nardelli, Marco & Bernholc, Jerry
System: The UNT Digital Library
Ab initio transport properties of nanostructures from maximally localized Wannier functions (open access)

Ab initio transport properties of nanostructures from maximally localized Wannier functions

Article on ab initio transport properties of nanostructures from maximally localized Wannier functions.
Date: January 22, 2004
Creator: Calzolari, Arrigo; Marzari, Nicola; Souza, Ivo & Buongiorno Nardelli, Marco
System: The UNT Digital Library
Mn Interstitial Diffusion in (Ga, Mn)As (open access)

Mn Interstitial Diffusion in (Ga, Mn)As

This article describes a combined theoretical and experimental study of the ferromagnetic semiconductor (Ga, Mn)As which explains the remarkably lard changes observed on low-temperature annealing.
Date: January 23, 2004
Creator: Edmonds, Kevin; Boguslawski, Piotr; Wang, K. Y.; Campion, Richard Paul; Novikov, Sergei; Farley, N. R. S. et al.
System: The UNT Digital Library
Lead (Pb2+) modulation of potassium currents of guinea pig outer hair cells (open access)

Lead (Pb2+) modulation of potassium currents of guinea pig outer hair cells

Article discussing lead (Pb2+) modulation of potassium currents of guinea pig outer hair cells.
Date: 2004
Creator: Liang, Guihua; Järlebark, Leif; Ulfendahl, Mats; Bian, Jing-Tan & Moore, Ernest J.
System: The UNT Digital Library
The Deep Web: Resource Discovery in the Library of Texas (open access)

The Deep Web: Resource Discovery in the Library of Texas

Article discussing the deep web and the new resource discovery service of the statewide virtual Library of Texas (LOT).
Date: 2004
Creator: Murray, Kathleen R. & Moen, William E.
System: The UNT Digital Library
Rapid Analysis of Legume Root Nodule Development Using Confocal Microscopy (open access)

Rapid Analysis of Legume Root Nodule Development Using Confocal Microscopy

This article discusses the rapid analysis of legume root nodule development using confocal microscopy.
Date: 2004
Creator: Haynes, Janine G.; Czymmek, Kirk J.; Carlson, Carol A.; Veereshlingam, Harita; Dickstein, Rebecca & Sherrier, D. Janine
System: The UNT Digital Library
LIN, a Medicago truncatula Gene Required for Nodule Differentiation and Persistence of Rhizobial Infections (open access)

LIN, a Medicago truncatula Gene Required for Nodule Differentiation and Persistence of Rhizobial Infections

Article on LIN, a Medicago truncatula gene required for nodule differentiation and persistence of rhizobial infections.
Date: November 2004
Creator: Kuppusamy, Kavitha T.; Endre, Gabriella; Prabhu, Radhika; Penmetsa, R. Varma; Veereshlingam, Harita; Cook, Douglas R. et al.
System: The UNT Digital Library
Non-Poisson Dichotomous Noise: Higher-Order Correlation Functions and Aging (open access)

Non-Poisson Dichotomous Noise: Higher-Order Correlation Functions and Aging

This article discusses non-Poisson dichotomous noise and higher-order correlation functions and aging.
Date: October 26, 2004
Creator: Allegrini, Paolo; Grigolini, Paolo; Palatella, Luigi & West, Bruce J.
System: The UNT Digital Library
Modeling Free Convection Flow of Liquid Hydrogen within a Cylindrical Heat Exchanger Cooled to 14 K (open access)

Modeling Free Convection Flow of Liquid Hydrogen within a Cylindrical Heat Exchanger Cooled to 14 K

None
Date: May 8, 2004
Creator: Green, Michael A.; Yang, S. W.; Green, M. A. & Lau, W.
System: The UNT Digital Library
SQUID-Detected MRI at 132 Microtesla with T1 Contrast Weighted at10 Microtelsa-300 mT (open access)

SQUID-Detected MRI at 132 Microtesla with T1 Contrast Weighted at10 Microtelsa-300 mT

None
Date: August 9, 2004
Creator: Lee, SeungKyun; Moessle, Michael; Myers, Whittier; Kelso, Nathan; Trabesinger, Andreas H.; Pines, Alex et al.
System: The UNT Digital Library
Relation between structural and optical properties of InN andInxGa1-xN thin films (open access)

Relation between structural and optical properties of InN andInxGa1-xN thin films

Transmission Electron Microscopy (TEM) and opticalmeasurements obtained from InN and In1-xGaxNfilms (0<x<0.54)grown by Molecular Beam Epitaxy are presented. Energy gaps measuredbyabsorption, PR, and PL for InN films grown on c-plane Al2O3 were in therange of 0.7 eV. No In or otherinclusions were observed in these films,ruling out the possibility of a strong Mie scattering mechanism. IntheIn1-xGaxN films the relationship between the structural properties andthe optical properties, inparticular the presence or absence of a Stokesshift between absorption and PL, is discussed. TEM studiesshow that highquality layers do not have a Stokes shift. Some films had compositionalordering; thesefilms also showed a shift between absorption edge andluminescence peak.
Date: July 20, 2004
Creator: Liliental-Weber, Z.; Zakharov, D. N.; Jasinski, J.; Yu, K. M.; Wu, J. W.; Ager, J. W., III et al.
System: The UNT Digital Library
Soft X-ray synchrotron radiation investigations of actinidematerials systems utilizing X-ray emission spectroscopy and resonantinelastic X-ray scattering (open access)

Soft X-ray synchrotron radiation investigations of actinidematerials systems utilizing X-ray emission spectroscopy and resonantinelastic X-ray scattering

Synchrotron radiation (SR) methods have been utilized with increasing frequency over the past several years to study topics in actinide science, ranging from those of a fundamental nature to those that address a specifically-targeted technical need. In particular, the emergence of microspectroscopic and fluorescence-based techniques have permitted investigations of actinide materials at sources of soft x-ray SR. Spectroscopic techniques with fluorescence-based detection are useful for actinide investigations since they are sensitive to small amounts of material and the information sampling depth may be varied. These characteristics also serve to simplify both sample preparation and safety considerations. Examples of investigations using these fluorescence techniques will be described along with their results, as well as the prospects for future investigations utilizing these methodologies.
Date: January 3, 2004
Creator: Shuh, D.K.; Butorin, S.M.; Guo, J.-H. & Nordgren, J.
System: The UNT Digital Library
Integrating automated shading and smart glazings with daylightcontrols (open access)

Integrating automated shading and smart glazings with daylightcontrols

None
Date: February 13, 2004
Creator: Selkowitz, Stephen & Lee, Eleanor
System: The UNT Digital Library
Hohlraum-driven ignition-like double-shell implosions on the Omega laser facility (open access)

Hohlraum-driven ignition-like double-shell implosions on the Omega laser facility

High-convergence ignition-like double-shell implosion experiments have been performed on the Omega laser facility [T.R. Boehly et al., Opt. Commun. 133, 495 (1997)] using cylindrical gold hohlraums with 40 drive beams. Repeatable, dominant primary (2.45 MeV) neutron production from the mix-susceptible compressional phase of a double-shell implosion, using fall-line design optimization and exacting fabrication standards, is experimentally inferred from time-resolved core x-ray imaging. Effective control of fuel-pusher mix during final compression is essential for achieving noncryogenic ignition with double-shell targets on the National Ignition Facility [Paisner et al., Laser Focus World 30, 75 (1994)].
Date: October 1, 2004
Creator: Amendt, P.; Robey, H. F.; Park, H. S.; Tipton, R. E.; Turner, R. E.; Milovich, J. L. et al.
System: The UNT Digital Library
Line-imaging velocimeter for shock diagnostics at the OMEGA laser facility (open access)

Line-imaging velocimeter for shock diagnostics at the OMEGA laser facility

None
Date: January 26, 2004
Creator: Celliers, P M; Bradley, D K; Collins, G W; Hicks, D G; Boehly, T R & Armstrong, W J
System: The UNT Digital Library
Performance characteristics of a cosmology package on leading HPCarchitectures (open access)

Performance characteristics of a cosmology package on leading HPCarchitectures

The Cosmic Microwave Background (CMB) is a snapshot of the Universe some 400,000 years after the Big Bang. The pattern of anisotropies in the CMB carries a wealth of information about the fundamental parameters of cosmology. Extracting this information is an extremely computationally expensive endeavor, requiring massively parallel computers and software packages capable of exploiting them. One such package is the Microwave Anisotropy Dataset Computational Analysis Package (MADCAP) which has been used to analyze data from a number of CMB experiments. In this work, we compare MADCAP performance on the vector-based Earth Simulator (ES) and Cray X1 architectures and two leading superscalar systems, the IBM Power3 and Power4. Our results highlight the complex interplay between the problem size, architectural paradigm, interconnect, and vendor-supplied numerical libraries, while isolating the I/O file system as the key bottleneck across all the platforms.
Date: January 1, 2004
Creator: Carter, Jonathan; Borrill, Julian & Oliker, Leonid
System: The UNT Digital Library
qSF wavefront triplication in a transversely isotropicmaterial (open access)

qSF wavefront triplication in a transversely isotropicmaterial

Triplication of a wavefront, also classically known as birefringence, can and does occur in transversely isotropic (TI) media. With the growing interest in shear waves, and in particular, converted shear waves, it becomes necessary to study this phenomenon, and the bright spots that accompany it. In a plane that includes the medium's rotational symmetry axis, there may exist a range of angles within which the qSV wave, whose polarization lies in that plane, may propagate at three distinct velocities. The region of the qSV wave curve where this can occur always corresponds to the region of the qSV slowness curve where the closed qSV curve about the origin is concave. When the range of angles is small and the three arrivals are close together, the usual situation, the qSV wave within that small range will be significantly brighter than in other directions. When the range of angles is large, the two cusps of the wave surface, on the borders of the region of triplication will both be bright spots.
Date: June 1, 2004
Creator: Schoenberg, Michael & Daley, Thomas M.
System: The UNT Digital Library
The dihadron fragmentation function and its evolution (open access)

The dihadron fragmentation function and its evolution

Dihadron fragmentation functions and their evolution arestudied in the process of e+e- annihilation. Under the collinearfactorization approximation and facilitated by the cut-vertex technique,the two hadron inclusive cross section at leading order (LO) is shown tofactorize into a short distance parton cross section and a long distancedihadron fragmentation function. We provide the definition of such adihadron fragmentation function in terms of parton matrix elements andderive its DGLAP evolution equation at leading log. The evolutionequation for the non-singlet quark fragmentation function is solvednumerically with a simple ansatz for the initial condition and resultsare presented for cases of physical interest.
Date: February 24, 2004
Creator: Majumder, Abhijit & Wang, Xin-Nian
System: The UNT Digital Library
Scheduling in Heterogeneous Grid Environments: The Effects of DataMigration (open access)

Scheduling in Heterogeneous Grid Environments: The Effects of DataMigration

Computational grids have the potential for solving large-scale scientific problems using heterogeneous and geographically distributed resources. However, a number of major technical hurdles must be overcome before this goal can be fully realized. One problem critical to the effective utilization of computational grids is efficient job scheduling. Our prior work addressed this challenge by defining a grid scheduling architecture and several job migration strategies. The focus of this study is to explore the impact of data migration under a variety of demanding grid conditions. We evaluate our grid scheduling algorithms by simulating compute servers, various groupings of servers into sites, and inter-server networks, using real workloads obtained from leading supercomputing centers. Several key performance metrics are used to compare the behavior of our algorithms against reference local and centralized scheduling schemes. Results show the tremendous benefits of grid scheduling, even in the presence of input/output data migration - while highlighting the importance of utilizing communication-aware scheduling schemes.
Date: January 1, 2004
Creator: Oliker, Leonid; Biswas, Rupak; Shan, Hongzhang & Smith, Warren
System: The UNT Digital Library
Proc. Agent 2004 Conf. on Social Dynamics : Interaction, Reflexivity and Emergence (open access)

Proc. Agent 2004 Conf. on Social Dynamics : Interaction, Reflexivity and Emergence

I'd like to welcome you to the Agent 2004 conference. As most of you are aware, this conference is the fifth in a series of meetings that began in 1999. A conference followed the next year in 2000. The 2001 conference was skipped because of some conflicts with other conferences, and the conferences have proceeded annually since then. We have the proceedings of the previous conferences available here on CDs. One CD has the proceedings from 1999, 2000, and 2002; the other contains last year's proceedings. The purpose of these conferences is to advance the state of the computational social sciences and to integrate the social sciences with the decision sciences and something that is traditionally known as the management sciences. Those of you in the operations/research area are familiar with the traditional school of modeling simulation that emerged from that scientific area. This conference will bring together a different group of people to talk about the topic of agent-based theories and simulations. This fifth agent conference is one of a group of conferences held annually around the country. Most of you are probably aware of the CASOS Conference held at Carnegie Mellon University, usually in July. UCLA holds the …
Date: January 1, 2004
Creator: C. M. Macal, D. Sallach, M. J. North, eds.
System: The UNT Digital Library
Two Dimensional Simulations of Plastic-Shell, Direct-Drive Implosions on OMEGA (open access)

Two Dimensional Simulations of Plastic-Shell, Direct-Drive Implosions on OMEGA

Multidimensional hydrodynamic properties of high-adiabat direct-drive plastic-shell implosions on the OMEGA laser system [T. R. Boehly et al., Opt. Commun. 133, 495 (1997)] are investigated using the multidimensional hydrodynamic code, DRACO. Multimode simulations including the effects of nonuniform illumination and target roughness indicate that shell stability during the acceleration phase plays a critical role in determining target performance. For thick shells that remain integral during the acceleration phase, target yields are significantly reduced by the combination of the long-wavelength ({ell} &lt; 10) modes due to surface roughness and beam imbalance and the intermediate modes (20 {le} {ell} {le} 50) due to single-beam nonuniformities. The neutron-production rate for these thick shells truncates relative to one-dimensional (1-D) predictions. The yield degradation in the thin shells is mainly due to shell breakup at short wavelengths ({lambda} {approx} {Delta}, where {Delta} is the in-flight shell thickness). The neutron-rate curves for the thinner shells have significantly lower amplitudes and a fall-off that is less steep than 1-D rates. DRACO simulation results are consistent with experimental observations.
Date: September 27, 2004
Creator: Radha, P. B.; Goncharov, V. N.; Collins, T. B.; Delettrez, J. A.; Elbaz, Y.; Glebov, V. Y. et al.
System: The UNT Digital Library
Low-frequency asymptotic analysis of seismic reflection from afluid-saturated medium (open access)

Low-frequency asymptotic analysis of seismic reflection from afluid-saturated medium

Reflection of a seismic wave from a plane interface betweentwo elastic media does not depend on the frequency. If one of the mediais poroelastic and fluid-saturated, then the reflection becomesfrequency-dependent. This paper presents a low-frequency asymptoticformula for the reflection of seismic plane p-wave from a fluid-saturatedporous medium. The obtained asymptotic scaling of the frequency-dependentcomponent of the reflection coefficient shows that it is asymptoticallyproportional to the square root of the product of the reservoir fluidmobility and the frequency of the signal. The dependence of this scalingon the dynamic Darcy's law relaxation time is investigated as well.Derivation of the main equations of the theory of poroelasticity from thedynamic filtration theory reveals that this relaxation time isproportional to Biot's tortuosity parameter.
Date: April 14, 2004
Creator: Silin, D.B.; Korneev, V.A.; Goloshubin, G.M. & Patzek, T.W.
System: The UNT Digital Library