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Articles 3301 - 3330 of 4091

Full-Text Articles in Physical Sciences and Mathematics

Enabling Remote Access To Personal Electronic Medical Records, James K. Archibald, Eric S. Hall, Charles D. Knutson, David K. Vawdrey May 2003

Enabling Remote Access To Personal Electronic Medical Records, James K. Archibald, Eric S. Hall, Charles D. Knutson, David K. Vawdrey

Faculty Publications

Millions of people suffer from medical conditions that should be made known to healthcare practitioners prior to treatment. Paramedics and emergency room doctors cannot provide optimal care without sufficient knowledge of a patient’s medical history. Lacking patient information such as allergies, current prescriptions, and preexisting conditions, medical professionals are often forced to either delay treatment or rely on instincts. Medical mistakes in situations like these kill thousands of people and cost an estimated US$37 billion each year in the United States [1]. With the advent of electronic medical records (EMRs), patient information can be stored in computer databases at hospitals …

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Optically Oriented And Detected Electron Spin Resonance In A Lightly Doped N-Gaas Layer, John S. Colton, T. A. Kennedy, A. S. Bracker, D. Gammon, J. B. Miller Apr 2003

Optically Oriented And Detected Electron Spin Resonance In A Lightly Doped N-Gaas Layer, John S. Colton, T. A. Kennedy, A. S. Bracker, D. Gammon, J. B. Miller

Faculty Publications

Spin resonance of localized electrons bound to donors in a specially designed n-GaAs layer has been performed at 236 MHz and 41 mT, using circular polarized light to polarize the electrons and photoluminescence to detect the electronic polarization. The polarization was diminished under the resonance condition. The electronic g factor obtained by this measurement is - 0.41 ± 0.01. The resonance linewidth of 2 mT corresponds to a spin lifetime of 28 ns. In order to observe the electronic spin resonance, nuclear effects were eliminated by application of rf fields to simultaneously resonate the nuclear spins.

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Measurement Of Subjet Multiplicities In Neutral Current Deep Inelastic Scattering At Hera And Determination Of ΑS, S. Chekanov, D. Krakauer, J. H. Loizides, S. Magill, B. Musgrave, J. Repond, R. Yoshida, Margarita C. K. Mattingly, P. Antonioli, G. Bari, M. Basile, L. Bellagamba, D. Boscherini, A. Bruni, G. Bruni, G. Cara Romeo, L. Cifarelli, F. Cindolo, A. Contin, M. Corradi, S. De Pasquale, P. Giusti, G. Iacobucci, A. Margotti, R. Nania, F. Palmonari, A. Pesci, G. Sartorelli, A. Zichichi, G. Aghuzumtsyan, D. Bartsch Apr 2003

Measurement Of Subjet Multiplicities In Neutral Current Deep Inelastic Scattering At Hera And Determination Of ΑS, S. Chekanov, D. Krakauer, J. H. Loizides, S. Magill, B. Musgrave, J. Repond, R. Yoshida, Margarita C. K. Mattingly, P. Antonioli, G. Bari, M. Basile, L. Bellagamba, D. Boscherini, A. Bruni, G. Bruni, G. Cara Romeo, L. Cifarelli, F. Cindolo, A. Contin, M. Corradi, S. De Pasquale, P. Giusti, G. Iacobucci, A. Margotti, R. Nania, F. Palmonari, A. Pesci, G. Sartorelli, A. Zichichi, G. Aghuzumtsyan, D. Bartsch

Faculty Publications

The subjet multiplicity has been measured in neutral current e+p interactions at Q2 > 125 GeV2 with the ZEUS detector at HERA using an integrated luminosity of 38.6 pb-1. Jets were identified in the laboratory frame using the longitudinally invariant kT cluster algorithm. The number of jet-like substructures within jets, known as the subjet multiplicity, is defined as the number of clusters resolved in a jet by reapplying the jet algorithm at a smaller resolution scale ycut. Measurements of the mean subjet multiplicity, (nsbj), for jets with transverse energies ET,jet > 15 GeV are presented. Next-to-leading-order perturbative QCD calculations describe the measurements …

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Search And Recovery Of The Space Shuttle Columbia: A Geospatial 1st Responder Perspective, Jeffrey M. Williams Apr 2003

Search And Recovery Of The Space Shuttle Columbia: A Geospatial 1st Responder Perspective, Jeffrey M. Williams

Faculty Publications

A first person account of the Texas geospatial volunteers and their efforts to recover the remains of the Space Shuttle Columbia and her crew lost over eastern Texas and western Louisiana on February 1st, 2003.

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Valuation Of Continuous And Intermittent Phragmites Control, R. Eugene Turner, R. S. Warren Apr 2003

Valuation Of Continuous And Intermittent Phragmites Control, R. Eugene Turner, R. S. Warren

Faculty Publications

Quantifying the relative value of Phragmites australis and Spartina alterniflora habitat is important to evaluate the benefits and risks of different attempts to address Phragmites expansion on the U.S. eastern seaboard. Two contrasting approaches commonly used to restore tidal marsh habitats invaded by Phragmites communities involve spraying Phragmites with herbicide only when its coverage of a particular marsh area is near or close to 100%. Alternatively, after the first application, herbicide is annually applied on any surviving patches of Phragmites present in a mosaic of other marsh vegetation. A model is introduced to evaluate the relative habitat value of these …

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Measurement Of Event Shapes In Deep Inelastic Scattering At Hera, S. Chekanov, D. Krakauer, J. H. Loizides, S. Magill, B. Musgrave, J. Repond, R. Yoshida, Margarita C. K. Mattingly, P. Antonioli, G. Bari, M. Basile, L. Bellagamba, D. Boscherini, A. Bruni, G. Bruni, G. Cara Romeo, L. Cifarelli, F. Cindolo, A. Contin, M. Corradi, S. De Pasquale, P. Giusti, G. Iacobucci, A. Margotti, R. Nania, F. Palmonari, A. Pesci, G. Sartorelli, A. Zichichi, G. Aghuzumtsyan, D. Bartsch Apr 2003

Measurement Of Event Shapes In Deep Inelastic Scattering At Hera, S. Chekanov, D. Krakauer, J. H. Loizides, S. Magill, B. Musgrave, J. Repond, R. Yoshida, Margarita C. K. Mattingly, P. Antonioli, G. Bari, M. Basile, L. Bellagamba, D. Boscherini, A. Bruni, G. Bruni, G. Cara Romeo, L. Cifarelli, F. Cindolo, A. Contin, M. Corradi, S. De Pasquale, P. Giusti, G. Iacobucci, A. Margotti, R. Nania, F. Palmonari, A. Pesci, G. Sartorelli, A. Zichichi, G. Aghuzumtsyan, D. Bartsch

Faculty Publications

Inclusive event-shape variables have been measured in the current region of the Breit frame for neutral current deep inelastic ep scattering using an integrated luminosity of 45.0 pb-1 collected with the ZEUS detector at HERA. The variables studied included thrust, jet broadening and invariant jet mass. The kinematic range covered was 10 < Q2 < 20480 GeV2 and 6 × 10-4 < x < 0.6, where Q2 is the virtuality of the exchanged boson and x is the Bjorken variable. The Q dependence of the shape variables has been used in conjunction with NLO perturbative calculations and the Dokshitzer-Webber non-perturbative corrections ('power corrections') to investigate the validity of this approach.

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Modes In A Non-Neutral Plasma Of Finite Length, M = 0,1, S. Neil Rasband, Ross L. Spencer Apr 2003

Modes In A Non-Neutral Plasma Of Finite Length, M = 0,1, S. Neil Rasband, Ross L. Spencer

Faculty Publications

For realistic, cold equilibria of finite length representing a pure electron plasma confined in a cylindrical Malmberg–Penning trap, the mode spectrum for Trivelpiece–Gould, m=0, and for diocotron, m=1, modes is calculated numerically. A novel method involving finite elements is used to successfully compute eigenfrequencies and eigenfunctions for plasma equilibria shaped like pancakes, cigars, long cylinders, and all things in between. Mostly sharp-boundary density configurations are considered but also included in this study are diffuse density profiles including ones with peaks off axis leading to instabilities. In all cases the focus has been on elucidating the role of finite length in …

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Influence Of A Cyclonic Eddy On Microheterotroph Biomass And Carbon Export In The Lee Of Hawaii, Robert R. Bidigare, Claudia R. Benitez-Nelson, Carrie L. Leonard, Paul D. Quay, Michael L. Parsons, David G. Foley, Michael P. Seki Mar 2003

Influence Of A Cyclonic Eddy On Microheterotroph Biomass And Carbon Export In The Lee Of Hawaii, Robert R. Bidigare, Claudia R. Benitez-Nelson, Carrie L. Leonard, Paul D. Quay, Michael L. Parsons, David G. Foley, Michael P. Seki

Faculty Publications

[1] A multi‐platform sampling strategy was used to investigate carbon cycling in a cold‐core eddy that formed in the lee of Hawaii during September 2000. Microheterotroph biomass and 234Th‐derived carbon export rates within the eddy were 2 to 3 times higher than those observed for adjacent waters. If this eddy is representative of other cyclonic eddies that are frequently formed in the lee of Hawaii, then eddy activity may significantly enhance the areal efficiency of the biological pump and facilitate the transfer of organic carbon to organisms inhabiting the mesopelagic and abyssal‐benthic zones of this subtropical ecosystem.

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Inverse Multiplexing In Short-Range Multi-Transport Wireless Communications, Lichen Dai, Heidi R. Duffin, James C. Funk, Charles D. Knutson Mar 2003

Inverse Multiplexing In Short-Range Multi-Transport Wireless Communications, Lichen Dai, Heidi R. Duffin, James C. Funk, Charles D. Knutson

Faculty Publications

This paper describes a mechanism for utilizing Inverse Multiplexing to significantly increase the bandwidth available to short-range wireless devices. Previous work with Inverse Multiplexing has focused on wired networks; its implementation with short-range wireless transports introduces heterogeneity in the links, which must be taken into account. A mathematical model for an Inverse Multiplexing system is derived for several scheduling algorithms. Both Process Limited and Transport Limited systems are examined. The validity of this model is shown by our implementation of an Inverse Multiplexing layer that uses IrDA and Bluetooth transports. Concepts related to Inverse Multiplexing such as usage models, negotiation, …

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Transport Discovery In Wireless Multi-Transport Environments, Shannon B. Barnes, Charles D. Knutson, Ryan W. Woodings Mar 2003

Transport Discovery In Wireless Multi-Transport Environments, Shannon B. Barnes, Charles D. Knutson, Ryan W. Woodings

Faculty Publications

In order to utilize multiple transports, devices must discover common mechanisms for communication, a procedure we call Multi-Transport Discovery. The Multi-Transport Discovery algorithm presented in this paper is a four-phase procedure (Transport Probing, Transport Querying, Address-to-Device Mapping, and Transport Accessibility) that can discover common transports within a multi-transport environment. Transport Probing uses a transport-dependent device discovery mechanism to discover an initial link. Transport Querying communicates over the probed link to query additional transports. Address-to-Device Mapping correctly correlates each transport to a remote device. Finally, Transport Accessibility periodically ascertains link availability during an application session.

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Probing Tectonic Topography In The Aftermath Of Continental Convergence In Central Europe, S Cloetingh, F Horvath, C Dinu, R A. Stephenson, G Bertotti, G Bada, L Matenco, D Garcia-Castellanos, P Andriessen, R Wortel, W Spakman, V Mocanu, C Langereis, W Krijgsman, J Fokkema, G Drykoningen, B Ambrosius, F Neubauer, L Fodor, T Dunai, E Willingshofer, A Nador, K Leever, M Tarapoanca, I Panea, I Vasiliev, G Paicu, A Van Der Hoven, James H. Knapp, Camelia C. Diaconescu, St Freimueller Mar 2003

Probing Tectonic Topography In The Aftermath Of Continental Convergence In Central Europe, S Cloetingh, F Horvath, C Dinu, R A. Stephenson, G Bertotti, G Bada, L Matenco, D Garcia-Castellanos, P Andriessen, R Wortel, W Spakman, V Mocanu, C Langereis, W Krijgsman, J Fokkema, G Drykoningen, B Ambrosius, F Neubauer, L Fodor, T Dunai, E Willingshofer, A Nador, K Leever, M Tarapoanca, I Panea, I Vasiliev, G Paicu, A Van Der Hoven, James H. Knapp, Camelia C. Diaconescu, St Freimueller

Faculty Publications

Continental topography is at the interface of processes taking place at depth in the Earth,at its surface,and above it.Topography influences society, not only in terms of slow processes of landscape change and earthquakes,but also in terms of how it affects climate.The Pannonian Basin–Carpathian Orogen System in Central and Eastern Europe represents a key natural laboratory for the development of a new generation of models for ongoing orogeny and its effect on continental topography development (Figure 1).This system comprises some of the best documented sedimentary basins in the world,located within the Alpine orogenic belt, at the transition between the western European …

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Gaussian And Mean Curvatures Of Rational Bézier Patches, Thomas W. Sederberg, Jianmin Zheng Mar 2003

Gaussian And Mean Curvatures Of Rational Bézier Patches, Thomas W. Sederberg, Jianmin Zheng

Faculty Publications

This note derives formulae for Gaussian and mean curvatures for tensor-product and triangular rational Bézier patches in terms of the respective control meshes. These formulae provide more geometric intuition than the generic formulae from differential geometry.

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Density Of States Simulations Of Proteins, Nitin Rathore, Thomas A. Knotts Iv, Juan J. De Pablo Mar 2003

Density Of States Simulations Of Proteins, Nitin Rathore, Thomas A. Knotts Iv, Juan J. De Pablo

Faculty Publications

A modified version of a recently introduced algorithm that calculates density of states by performing a random walk in energy space has been proposed and implemented to study protein folding in a continuum. A united atom representation and the CHARMM19 [B. R. Brooks, R. E. Bruccoleri, B. D. Olafson, D. J. States, S. Swaminathan, and M. Karplus, J. Comput. Chem. 4, 187 (1983)] force field are employed for these simulations. This method permits estimation of the density of states of a protein via a random walk in the energy space, thereby allowing the system to escape from local free-energy minima …

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Measurements Of Inelastic J/Ψ And Ψ′ Photoproduction At Hera, S. Chekanov, D. Krakauer, S. Magill, B. Musgrave, J. Repond, R. Yoshida, Margarita C. K. Mattingly, P. Antonioli, G. Bari, M. Basile, L. Bellagamba, D. Boscherini, A. Bruni, G. Bruni, G. Cara Romeo, L. Cifarelli, F. Cindolo, A. Contin, M. Corradi, S. De Pasquale, P. Giusti, G. Iacobucci, A. Margotti, R. Nania, F. Palmonari, A. Pesci, G. Sartorelli, A. Zichichi, G. Aghuzumtsyan, D. Bartsch, I. Brock Mar 2003

Measurements Of Inelastic J/Ψ And Ψ′ Photoproduction At Hera, S. Chekanov, D. Krakauer, S. Magill, B. Musgrave, J. Repond, R. Yoshida, Margarita C. K. Mattingly, P. Antonioli, G. Bari, M. Basile, L. Bellagamba, D. Boscherini, A. Bruni, G. Bruni, G. Cara Romeo, L. Cifarelli, F. Cindolo, A. Contin, M. Corradi, S. De Pasquale, P. Giusti, G. Iacobucci, A. Margotti, R. Nania, F. Palmonari, A. Pesci, G. Sartorelli, A. Zichichi, G. Aghuzumtsyan, D. Bartsch, I. Brock

Faculty Publications

The cross sections for inelastic photoproduction of J/ψ and ψ′ mesons have been measured in ep collisions with the ZEUS detector at HERA, using an integrated luminosity of 38.0 pb-1. The events were required to have 0.1 < z < 0.9 and 50 < W < 180 GeV, where z is the fraction of the incident photon energy carried by the J/ψ in the proton rest frame and W is the photon-proton centre-of-mass energy. The ψ′ to J/ψ cross-section ratio was measured in the range 0.55 < z < 0.9. The J/ψ data, for various ranges of transverse momentum, are compared to theoretical models incorporating colour-singlet and colour-octet matrix elements. Predictions of a next-to-leading-order colour-singlet model give a good description of the data, although there is a large normalisation uncertainty. The J/ψ helicity distribution for z > 0.4 is compared to leading-order QCD predictions.

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What The Universe Means To People Like Me, David D. Allred Mar 2003

What The Universe Means To People Like Me, David D. Allred

Faculty Publications

When I picked up David's paper to read it, I had a pencil in my hand. Years of reading my students' and my own papers made it natural to edit as I read. However, I heard in my mind the voice of my mother advising me to put the pencil down. This wasn't time to edit but to hear and understand. Still, I kept the pencil in my hand for the first few pages and made a few notes before I put it down and just read. I could hear David's voice speaking the words I read. It was good …

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Neutral-Plasma Oscillations At Zero Temperature, Scott D. Bergeson, Ross L. Spencer Feb 2003

Neutral-Plasma Oscillations At Zero Temperature, Scott D. Bergeson, Ross L. Spencer

Faculty Publications

Cold plasma theory is used to calculate the response of an ultracold neutral plasma to an applied rf field. The free oscillation of the system has a continuous spectrum and an associated damped quasimode. This quasimode dominates the driven response and is resonant in the tail of the density distribution. Recent experiments used the plasma response to an applied rf field to determine the plasma density in an expanding ultracold plasma. The comparison between experiment and theory indicates that this method accurately determines the expansion velocity and underestimates the initial plasma density by a factor of 3 in weakly collisional …

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Review Of The Final Frontier, Michael F. Russo Feb 2003

Review Of The Final Frontier, Michael F. Russo

Faculty Publications

No abstract provided.

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Semiclassical Dynamics With Quantum Trajectories: Formulation And Comparison With The Semiclassical Initial Value Representation Propagator, Sophya Garashchuk, Vitaly A. Rassolov Feb 2003

Semiclassical Dynamics With Quantum Trajectories: Formulation And Comparison With The Semiclassical Initial Value Representation Propagator, Sophya Garashchuk, Vitaly A. Rassolov

Faculty Publications

We present a time-dependent semiclassical method based on quantum trajectories. Quantum-mechanical effects are described via the quantum potential computed from the wave function density approximated as a linear combination of Gaussian fitting functions. The number of the fitting functions determines the accuracy of the approximate quantum potential (AQP). One Gaussian fit reproduces time-evolution of a Gaussian wave packet in a parabolic potential. The limit of the large number of fitting Gaussians and trajectories gives the full quantum-mechanical result. The method is systematically improvable from classical to fully quantum. The fitting procedure is implemented as a gradient minimization. We also compare …

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Observation Of The Strange Sea In The Proton Via Inclusive Φ-Meson Production In Neutral Current Deep Inelastic Scattering At Hera, S. Chekanov, D. Krakauer, S. Magill, B. Musgrave, J. Repond, R. Yoshida, Margarita C. K. Mattingly, P. Antonioli, G. Bari, M. Basile, L. Bellagamba, D. Boscherini, A. Bruni, G. Bruni, G. Cara Romeo, L. Cifarelli, F. Cindolo, A. Contin, M. Corradi, S. De Pasquale, P. Giusti, G. Iacobucci, A. Margotti, R. Nania, F. Palmonari, A. Pesci, G. Sartorelli, A. Zichichi, G. Aghuzumtsyan, D. Bartsch, I. Brock Feb 2003

Observation Of The Strange Sea In The Proton Via Inclusive Φ-Meson Production In Neutral Current Deep Inelastic Scattering At Hera, S. Chekanov, D. Krakauer, S. Magill, B. Musgrave, J. Repond, R. Yoshida, Margarita C. K. Mattingly, P. Antonioli, G. Bari, M. Basile, L. Bellagamba, D. Boscherini, A. Bruni, G. Bruni, G. Cara Romeo, L. Cifarelli, F. Cindolo, A. Contin, M. Corradi, S. De Pasquale, P. Giusti, G. Iacobucci, A. Margotti, R. Nania, F. Palmonari, A. Pesci, G. Sartorelli, A. Zichichi, G. Aghuzumtsyan, D. Bartsch, I. Brock

Faculty Publications

Inclusive φ(1020)-meson production in neutral current deep inelastic e+p scattering has been measured with the ZEUS detector at HERA using an integrated luminosity of 45 pb-1. The φ mesons were studied in the range 10 < Q2 < 100 GeV2, where Q2 is the virtuality of the exchanged photon, and in restricted kinematic regions in the transverse momentum, pT, pseudorapidity, η, and the scaled momentum in the Breit frame, xp. Monte Carlo models with the strangeness-suppression factor as determined by analyses of e+e- annihilation events overestimate the cross sections. A smaller value of the strangeness-suppression factor reduces the predicted cross sections, but fails to reproduce the shapes of the measured differential cross sections. High-momentum φ mesons in the current region of the Breit frame give the first direct evidence for the strange sea in the proton at low x. © 2002 Published by Elsevier Science B.V.

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Chemomechanical Surface Patterning And Functionalization Of Silicon Surfaces Using An Atomic Force Microscope, Brent A. Wascaser, Michael J. Maughan, Travis L. Niederhauser, Matthew R. Linford, Robert C. Davis, Ian A. Mowat Feb 2003

Chemomechanical Surface Patterning And Functionalization Of Silicon Surfaces Using An Atomic Force Microscope, Brent A. Wascaser, Michael J. Maughan, Travis L. Niederhauser, Matthew R. Linford, Robert C. Davis, Ian A. Mowat

Faculty Publications

Surface modification and patterning at the nanoscale is a frontier in science with significant possible applications in biomedical technology and nanoelectronics. Here we show that an atomic force microscope (AFM) can be employed to simultaneously pattern and functionalize hydrogen-terminated silicon (111) surfaces. The AFM probe was used to break Si-H and Si-Si bonds in the presence of reactive molecules, which covalently bonded to the scribed Si surface. Functionalized patches and patterned lines of molecules were produced. Linewidths down to 30 nm were made by varying the force at the tip

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Climatic Influences On Riverine Nitrate Flux: Implications For Coastal Marine Eutrophication And Hypoxia, Dubravko Justic, R. Eugene Turner, Nancy N. Rabalais Feb 2003

Climatic Influences On Riverine Nitrate Flux: Implications For Coastal Marine Eutrophication And Hypoxia, Dubravko Justic, R. Eugene Turner, Nancy N. Rabalais

Faculty Publications

The average nitrate flux of the lower Mississippi River increased 3.3-fold between 1954–1967 and 1983–2000. During the same time period, the average nitrate concentration increased 2.3-fold while the average discharge increased 40%. Partitioning of the observed trend in nitrate flux among the two flux components, nitrate concentration and discharge, revealed that about 80% of the observed increase in flux could be explained by the increase in nitrate concentration. This indicates that a historical increase in the anthropogenic nutrient inputs has had a far greater impact on the lower Mississippi River nitrate flux than a change in climate. The influence of …

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Efficient Incorporation Of Coa, Nad And Fad Into Rna By In Vitro Transcription, Faqing Huang Feb 2003

Efficient Incorporation Of Coa, Nad And Fad Into Rna By In Vitro Transcription, Faqing Huang

Faculty Publications

Protein enzymes frequently recruit small molecule coenzymes to perform a variety of biochemical reactions. While the catalytic activities of RNA have been expanding rapidly, a similar strategy for RNA to utilize coenzymes and to increase its functional capabilities has yet to be demonstrated. A general in vitro transcription procedure has been developed to efficiently prepare RNA with coenzymes CoA, NAD and FAD covalently attached to the 5' end. These adenosine-containing coenzymes initiate transcription under the T7 class II promoter by T7 RNA polymerase. In addition to the three coenzymes, other adenosine-containing molecules may be incorporated into the first nucleotide position …

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Zeus Next-To-Leading-Order Qcd Analysis Of Data On Deep Inelastic Scattering, S. Chekanov, D. Krakauer, S. Magill, B. Musgrave, J. Repond, R. Yoshida, G. Bruni, G. Cara Romeo, L. Cifarelli, F. Cindolo, A. Contin, M. Corradi, S. De Pasquale, P. Giusti, G. Iacobucci, A. Margotti, R. Nania, F. Palmonari, A. Pesci, G. Sartorelli, A. Zichichi, H. Labes, D. Lelas, B. Löhr, R. Mankel, M. Martínez, I. A. Melzer-Pellmann, M. Moritz, D. Notz, M. C. Petrucci, A. Polini Jan 2003

Zeus Next-To-Leading-Order Qcd Analysis Of Data On Deep Inelastic Scattering, S. Chekanov, D. Krakauer, S. Magill, B. Musgrave, J. Repond, R. Yoshida, G. Bruni, G. Cara Romeo, L. Cifarelli, F. Cindolo, A. Contin, M. Corradi, S. De Pasquale, P. Giusti, G. Iacobucci, A. Margotti, R. Nania, F. Palmonari, A. Pesci, G. Sartorelli, A. Zichichi, H. Labes, D. Lelas, B. Löhr, R. Mankel, M. Martínez, I. A. Melzer-Pellmann, M. Moritz, D. Notz, M. C. Petrucci, A. Polini

Faculty Publications

Next-to-leading-order QCD analyses of the ZEUS data on deep inelastic scattering together with fixed-target data have been performed, from which the gluon and quark densities of the proton and the value of the strong coupling constant (Formula presented) were extracted. The study includes a full treatment of the experimental systematic uncertainties including point-to-point correlations. The resulting uncertainties in the parton density functions are presented. A combined fit for (Formula presented) and the gluon and quark densities yields a value for (Formula presented) in agreement with the world average. The parton density functions derived from ZEUS data alone indicate the importance …

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Sediment Transport By Dry Ravel, Emmanuel Gabet Jan 2003

Sediment Transport By Dry Ravel, Emmanuel Gabet

Faculty Publications

Dry ravel is a general term that describes the rolling, bouncing, and sliding of individual particles down a slope and is a dominant hillslope sediment transport process in steep arid and semiarid landscapes. During fires, particles can be mobilized by the collapse of sediment wedges that have accumulated behind vegetation. On a daily basis, particles may be mobilized by bioturbation and by small landslides. Experiments on a dry ravel flume indicate that a basic expression of the momentum equation predicts the distance traveled by particles propelled down a rough surface. This equation is further elaborated to produce a nonlinear slope-dependent …

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Every Three-Point Set Is Zero Dimensional, David L. Fearnley, J. W. Lamoreaux, David L. Fearnley Jan 2003

Every Three-Point Set Is Zero Dimensional, David L. Fearnley, J. W. Lamoreaux, David L. Fearnley

Faculty Publications

This paper answers a question of Jan J. Dijkstra by giving a proof that all three-point sets are zero dimensional. It is known that all two-point sets are zero dimensional, and it is known that for all n > 3, there are n-point sets which are not zero dimensional, so this paper answers the question for the last remaining case.

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Magmatic Subsidence Of The East Pacific Rise (Epr) At 18˚14'S Revealed Through Fault Restoration Of Ridge Crest Bathymetry, S M. Carbotte, William B F Ryan, Wen Jin, Marie-Helene Cormier, Eric Bergmanis, John Sinton, Scott M. White Jan 2003

Magmatic Subsidence Of The East Pacific Rise (Epr) At 18˚14'S Revealed Through Fault Restoration Of Ridge Crest Bathymetry, S M. Carbotte, William B F Ryan, Wen Jin, Marie-Helene Cormier, Eric Bergmanis, John Sinton, Scott M. White

Faculty Publications

The fault restoration technique of De Chabalier and Avouac [1994] is applied to an ultra-highresolution bathymetry data set from the East Pacific Rise (EPR) at 18140S. Fault offsets are calculated and subtracted from the original seafloor bathymetry to examine the morphology of the unfaulted seafloor surface within an area encompassing the ridge axis 400 [1] 1600 m in dimension. The restored topography reveals a gently sloping seafloor 200 m wide, which slopes 5 inward toward the spreading axis. We attribute this inward sloping seafloor to subsidence within the axial trough due to subsurface magmatic deflation. The vertical deformation field extracted …

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Study Of The Azimuthal Asymmetry Of Jets In Neutral Current Deep Inelastic Scattering At Hera, S. Chekanov, D. Krakauer, S. Magill, B. Musgrave, J. Repond, R. Yoshida, Margarita C. K. Mattingly, P. Antonioli, G. Bari, M. Basile, L. Bellagamba, D. Boscherini, A. Bruni, G. Bruni, G. Cara Romeo, L. Cifarelli, F. Cindolo, A. Contin, M. Corradi, S. De Pasquale, P. Giusti, G. Iacobucci, A. Margotti, R. Nania, F. Palmonari, A. Pesci, G. Sartorelli, A. Zichichi, G. Aghuzumtsyan, D. Bartsch, I. Brock Jan 2003

Study Of The Azimuthal Asymmetry Of Jets In Neutral Current Deep Inelastic Scattering At Hera, S. Chekanov, D. Krakauer, S. Magill, B. Musgrave, J. Repond, R. Yoshida, Margarita C. K. Mattingly, P. Antonioli, G. Bari, M. Basile, L. Bellagamba, D. Boscherini, A. Bruni, G. Bruni, G. Cara Romeo, L. Cifarelli, F. Cindolo, A. Contin, M. Corradi, S. De Pasquale, P. Giusti, G. Iacobucci, A. Margotti, R. Nania, F. Palmonari, A. Pesci, G. Sartorelli, A. Zichichi, G. Aghuzumtsyan, D. Bartsch, I. Brock

Faculty Publications

The azimuthal distribution of jets produced in the Breit frame in high-Q2 deep inelastic e+p scattering has been studied with the ZEUS detector at HERA using an integrated luminosity of 38.6 pb-1. The measured azimuthal distribution shows a structure that is well described by next-to-leading-order QCD predictions over the Q2 range considered, Q2 > 125 GeV2. © 2002 Elsevier Science B.V. All rights reserved.

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Odd Perfect Numbers Have A Prime Factor Exceeding 10^7, Paul M. Jenkins Jan 2003

Odd Perfect Numbers Have A Prime Factor Exceeding 10^7, Paul M. Jenkins

Faculty Publications

It is proved that every odd perfect number is divisible by a prime greater than 10^7.

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Sediment Detachment By Rain Power, Emmanuel Gabet, Thomas Dunne Jan 2003

Sediment Detachment By Rain Power, Emmanuel Gabet, Thomas Dunne

Faculty Publications

In interrill areas, overland flow is often incapable of detaching soil particles so detachment is primarily by raindrop impact. We derive a mathematical expression, rain power (R, W m−2), relating the energy expenditure of raindrops impacting a soil surface to the rate of detachment of soil particles. Rain power incorporates rainfall, hillslope, and vegetation characteristics and is modulated by flow depths. Rainfall simulation experiments on natural hillslopes were performed to measure detachment rates and across-slope flow depth distributions in surface runoff. Our results indicate that flow depths follow a Poisson distribution, and this observation is used to develop a dimensionless …

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A Direct Simulation Monte Carlo Method For The Uehling-Uhlenbeck-Boltzmann Equation, Alejandro Garcia, W. Wagner Jan 2003

A Direct Simulation Monte Carlo Method For The Uehling-Uhlenbeck-Boltzmann Equation, Alejandro Garcia, W. Wagner

Faculty Publications

In this paper we describe a direct simulation Monte Carlo algorithm for the Uehling-Uhlenbeck-Boltzmann equation in terms of Markov processes. This provides a unifying framework for both the classical Boltzmann case as well as the Fermi-Dirac and Bose-Einstein cases. We establish the foundation of the algorithm by demonstrating its link to the kinetic equation. By numerical experiments we study its sensitivity to the number of simulation particles and to the discretization of the velocity space, when approximating the steady-state distribution.

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