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2010

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Articles 14341 - 14370 of 16047

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Polarized Neutron Reflectometry Study Of The Magnetization Reversal Process In Yba2cu3o7 /La2/3ca1/3mno3 Superlattices Grown On Srtio3 Substrates, J. Hoppler, H. Fritzsche, V. K. Malik, J. Stahn, G. P. Cristiani, H.-U. Habermeier, M. Rössle, Jan Honolka, Axel Enders, C. Bernhard Jan 2010

Polarized Neutron Reflectometry Study Of The Magnetization Reversal Process In Yba2cu3o7 /La2/3ca1/3mno3 Superlattices Grown On Srtio3 Substrates, J. Hoppler, H. Fritzsche, V. K. Malik, J. Stahn, G. P. Cristiani, H.-U. Habermeier, M. Rössle, Jan Honolka, Axel Enders, C. Bernhard

Axel Enders Publications

Using polarized neutron reflectometry we investigated the reversal of the magnetization of a high-Tc superconductor/ferromagnet superlattice that consists of eight bilayers of YBa2Cu3O7(25.6 nm) /La2/3Ca1/3MnO3(25.6 nm) grown on a SrTiO3 substrate. The measurements were performed during a magnetization hysteresis loop at 5 K. We obtained evidence that the reversal in the vicinity of the coercive field proceeds via the switching of micrometer-sized magnetic domains that are considerably larger than the typical domains of La2/3Ca1/3MnO3. Furthermore, these large magnetic domains …

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Cobalt Nanoclusters On Metal-Supported Xe Monolayers: Influence Of The Substrate On Cluster Formation Kinetics And Magnetism, V. Sessi, K. Kuhnke, J. Zhang, Jan Honolka, Klaus Kern, Axel Enders, P. Bencok, S. Bornemann, Ján Minár, Hubert Ebert Jan 2010

Cobalt Nanoclusters On Metal-Supported Xe Monolayers: Influence Of The Substrate On Cluster Formation Kinetics And Magnetism, V. Sessi, K. Kuhnke, J. Zhang, Jan Honolka, Klaus Kern, Axel Enders, P. Bencok, S. Bornemann, Ján Minár, Hubert Ebert

Axel Enders Publications

The growth dynamics of submonolayer coverages of cobalt during buffer layer assisted growth on Ag(111) and Pt(111) substrates is investigated by variable temperature scanning tunneling microscopy in the temperature range between 80 and 150 K. It is found that attractive cluster-substrate interactions can govern the cluster formation on the Xe buffer layer if the Xe layer is sufficiently thin. The interpretation of the microscopy results is supported by x-ray magnetic circular dichroism data which monitor the effect of cluster-substrate interactions on the formation of magnetic moments and magnetic anisotropy of Co nanocluster during the different stages of growth. Ab initio …

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Self-Assembly And Properties Of Nonmetalated Tetraphenyl-Porphyrin On Metal Substrates, Geoffrey Rojas, Xumin Chen, Cameron Bravo, Ji-Hyun Kim, Jae-Sung Kim, Jie Xiao, Peter A. Dowben, Yi Gao, Xiao Cheng Zeng, Wonyoung Choe, Axel Enders Jan 2010

Self-Assembly And Properties Of Nonmetalated Tetraphenyl-Porphyrin On Metal Substrates, Geoffrey Rojas, Xumin Chen, Cameron Bravo, Ji-Hyun Kim, Jae-Sung Kim, Jie Xiao, Peter A. Dowben, Yi Gao, Xiao Cheng Zeng, Wonyoung Choe, Axel Enders

Axel Enders Publications

The structure−electronic structure relationship of nonmetalated meso-tetraphenyl porphyrin (2H-TPP) on the (111) surfaces of Ag, Cu, and Au was studied with a combination of scanning tunneling microscopy, photoelectron spectroscopy, and density functional theory. We observe that the molecules form a 2D network on Ag(111), driven by attractive intermolecular interactions, while the surface migration barriers are comparatively small and the charge transfer to the adsorbed molecules is minimal. This is in contrast to a significant charge transfer observed in 2H-TPP/Cu(111), resulting in repulsive forces between the molecules that prevent molecular adlayer network formation. It is shown that the limiting factor in …

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Magnetic And Optical Properties Of Multiferroic Gdmno3 Nanoparticles, X. L. Wang, D. Li, T. Y. Cui, Parashu Kharel, W. Liu, Z. D. Zhang Jan 2010

Magnetic And Optical Properties Of Multiferroic Gdmno3 Nanoparticles, X. L. Wang, D. Li, T. Y. Cui, Parashu Kharel, W. Liu, Z. D. Zhang

Department of Physics and Astronomy: Faculty Publications

The magnetic and optical properties of multiferroic GdMnO3 nanoparticles synthesized by a polymerized complex method have been investigated. The GdMnO3 nanoparticles crystallized in orthorhombic perovskite-type structure. The zero-field-cooled and field-cooled magnetizations show that complicated magnetic transitions occur in a temperature range from 2 to 60 K, which were confirmed by magnetic hysteresis loops. Three shoulder absorption peaks centered at about 2.0, 2.3, and 2.7 eV are attributed to the Mn (3d)-electronic transitions, while an absorption peak at around 4.1 eV corresponds to the charge-transfer transitions between O (2p) and Mn (3d) states. UV emission at about 396 and …

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Orientational Order Of A Ferroelectric Liquid Crystal With Small Layer Contraction, Rafal Korlacki, Vitaly P. Panov, Atsuo Fukuda, Jagdish K. Vij, Christopher M. Spillmann, Jawad Naciri Jan 2010

Orientational Order Of A Ferroelectric Liquid Crystal With Small Layer Contraction, Rafal Korlacki, Vitaly P. Panov, Atsuo Fukuda, Jagdish K. Vij, Christopher M. Spillmann, Jawad Naciri

Department of Physics and Astronomy: Faculty Publications

We present spectroscopic and optical studies of a non-layer-shrinkage ferroelectric liquid crystal DSiKN65. The orientational order parameters S, measured with respect to the smectic layer normal using IR spectroscopy on a sample aligned homeotropically, does not exhibit any significant variation between the smectic-A* and smectic-C* phases. In contrast the birefringence of a planar homogenous sample abruptly increases at the smectic-A* to smectic-C* transition. This suggests a general increase in the orientational order, which can be described by the orientational order parameters S' defined with respect to the director. Simultaneous increase of S' and the director …

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Deposition Of High-Quality Hfo2 On Graphene And The Effect Of Remote Oxide Phonon Scattering, K. Zou, X. Hong, D. Keefer, J. Zhu Jan 2010

Deposition Of High-Quality Hfo2 On Graphene And The Effect Of Remote Oxide Phonon Scattering, K. Zou, X. Hong, D. Keefer, J. Zhu

Xia Hong Publications

We demonstrate atomic layer deposition of high-quality dielectric HfO2 films on graphene and determine the magnitude of remote oxide surface phonon scattering in dual-oxide structures. The carrier mobility in these HfO2-covered graphene samples reaches 20 000 cm2/Vs at low temperature. Distinct contributions to the resistivity from surface optical phonons in the SiO2 substrate and the HfO2 overlayer are isolated. At 300 K, surface phonon modes of the HfO2 film centered at 54 meV limit the mobility to approximately 20 000 cm2/Vs.

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Unusual Resistance Hysteresis In N-Layer Graphene Field Effect Transistors Fabricated On Ferroelectric Pb(Zr0.2Ti0.8)O3, X. Hong, J. Hoffman, A. Posadas, K. Zou, C. H. Ahn, J. Zhu Jan 2010

Unusual Resistance Hysteresis In N-Layer Graphene Field Effect Transistors Fabricated On Ferroelectric Pb(Zr0.2Ti0.8)O3, X. Hong, J. Hoffman, A. Posadas, K. Zou, C. H. Ahn, J. Zhu

Xia Hong Publications

We have fabricated n-layer graphene field effect transistors on epitaxial ferroelectric Pb(Zr0.2Ti0.8)O3 (PZT) thin films. At low gate voltages, PZT behaves as a high-k dielectric with k up to 100. An unusual resistance hysteresis occurs in gate sweeps at high voltages, with its direction opposite to that expected from the polarization switching of PZT. The relaxation of the metastable state is thermally activated, with an activation barrier of 50–110 meV and a time constant of 6 h at 300 K. We attribute its origin to the slow dissociation/recombination dynamics of water molecules adsorbed at …

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Interstitial-Nitrogen Effect On Phase Transition And Magnetocaloric Effect In Mn(As,Si) (Invited), W. B. Cui, X. K. Lv, F. Yang, Ralph Skomski, Y. Yu, X. G. Zhao, W. Liu, Z.D. Zhang Jan 2010

Interstitial-Nitrogen Effect On Phase Transition And Magnetocaloric Effect In Mn(As,Si) (Invited), W. B. Cui, X. K. Lv, F. Yang, Ralph Skomski, Y. Yu, X. G. Zhao, W. Liu, Z.D. Zhang

Ralph Skomski Publications

The effect of interstitial nitrogen on the phase transition and magnetocaloric behavior of MnAs1−xSixNδ (x=0.03, 0.06, and 0.09) is investigated. The interstitial nitrogen atoms cause the step-scanned x-ray diffraction peaks to shift toward lower angles and lower the Curie temperature, whereas silicon addition increases the Curie temperature to near room temperature. The thermal hysteresis is reduced to nearly 0 in MnAs1−xSixNδ, which is beneficial to practical applications. For a field change of 5 T, the largest magnetic entropy change and refrigerant capacity are 14.6 J kg−1 K−1 …

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Entropy Localization In Magnetic Compounds And Thin-Film Nanostructures, Ralph Skomski, Christian Binek, Steven A. Michalski, Tathagata Mukherjee, Axel Enders, David J. Sellmyer Jan 2010

Entropy Localization In Magnetic Compounds And Thin-Film Nanostructures, Ralph Skomski, Christian Binek, Steven A. Michalski, Tathagata Mukherjee, Axel Enders, David J. Sellmyer

Ralph Skomski Publications

The effect of nanostructuring on the magnetic entropy of materials for room-temperature magnetic cooling is investigated by model calculations. The materials are structurally inhomogeneous with a large number of nonequivalent crystallographic sites. In the mean-field Heisenberg model, the entropy density is a unique function of the local magnetization so that the coupled set of nonlinear mean-field equations yields not only the magnetization but also the entropy density. Since most of the entropy is localized near grain boundaries, nanomagnetic cooling requires small feature sizes. Magnetic anisotropy is a substantial complication, even on a mean-field level, but the corresponding corrections are often …

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Cms: Transverse-Momentum And Pseudorapidity Distributions Of Charged Hadrons In Pp Collisions At P [?] = 0.9 And 2.36tev, S. Chatrchyan, Ekaterina Avdeeva, Kenneth Bloom, S. Bose, Jamila Butt, Daniel R. Claes, Aaron Dominguez, M. Eads, R. Gonzalez Suarez, P. Jindal, J. Keller, D. Knowlton, Ilya Kravchenko, Jose Lazo-Flores, Helena Malbouisson, Sudhir Malik, F. Meier, Gregory Snow Jan 2010

Cms: Transverse-Momentum And Pseudorapidity Distributions Of Charged Hadrons In Pp Collisions At P [?] = 0.9 And 2.36tev, S. Chatrchyan, Ekaterina Avdeeva, Kenneth Bloom, S. Bose, Jamila Butt, Daniel R. Claes, Aaron Dominguez, M. Eads, R. Gonzalez Suarez, P. Jindal, J. Keller, D. Knowlton, Ilya Kravchenko, Jose Lazo-Flores, Helena Malbouisson, Sudhir Malik, F. Meier, Gregory Snow

Gregory Snow Publications

Measurements of inclusive charged-hadron transverse-momentum and pseudorapidity distributions are presented for proton-proton collisions at [?] = 0.9 and 2.36 TeV. The data were collected with the CMS detector during the LHC commissioning in December 2009. For non-single-diffractive interactions, the average charged-hadron transverse momentum is measured to be 0:46 ± 0:01 (stat.) ± 0.01 (syst.) GeV/c at 0.9 TeV and 0:50 ± 0:01 (stat.) ± 0.01 (syst.) GeV/c at 2.36 TeV, for pseudorapidities between -2:4 and +2:4. At these energies, the measured pseudorapidity densities in the central region, dNch/dn||n|<0.5, are 3.48±0.02 (stat.) ± 0.13 …

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Cms: Observation Of Long-Range, Near-Side Angular Correlations In Proton-Proton Collisions At The Lhc, S. Chatrchyan, Ekaterina Avdeeva, Kenneth Bloom, S. Bose, Jamila Butt, Daniel R. Claes, Aaron Dominguez, M. Eads, R. Gonzalez Suarez, P. Jindal, J. Keller, D. Knowlton, Ilya Kravchenko, Jose Lazo-Flores, Helena Malbouisson, Sudhir Malik, F. Meier, Gregory Snow Jan 2010

Cms: Observation Of Long-Range, Near-Side Angular Correlations In Proton-Proton Collisions At The Lhc, S. Chatrchyan, Ekaterina Avdeeva, Kenneth Bloom, S. Bose, Jamila Butt, Daniel R. Claes, Aaron Dominguez, M. Eads, R. Gonzalez Suarez, P. Jindal, J. Keller, D. Knowlton, Ilya Kravchenko, Jose Lazo-Flores, Helena Malbouisson, Sudhir Malik, F. Meier, Gregory Snow

Gregory Snow Publications

Results on two-particle angular correlations for charged particles emitted in proton-proton collisions at center-of-mass energies of 0.9, 2.36, and 7TeV are presented, using data collected with the CMS detector over a broad range of pseudorapidity (n) and azimuthal angle (?). Short-range correlations in [?]n, which are studied in minimum bias events, are characterized using a simple \independent cluster" parametrization in order to quantify their strength (cluster size) and their extent in n (cluster decay width). Long-range azimuthal correlations are studied differentially as a function of charged particle multiplicity and particle transverse momentum using a 980 nb …

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Lattice Dynamical Probe Of Charge Order And Antipolar Bilayer Stacking In Lufe2o4, X. S. Xu, J. De Groot, Q.-C. Sun, B. C. Sales, D. Mandrus, M. Angst, A. P. Litvinchuk, J. L. Musfeldt Jan 2010

Lattice Dynamical Probe Of Charge Order And Antipolar Bilayer Stacking In Lufe2o4, X. S. Xu, J. De Groot, Q.-C. Sun, B. C. Sales, D. Mandrus, M. Angst, A. P. Litvinchuk, J. L. Musfeldt

Xiaoshan Xu Papers

We investigated the infrared response of LuFe2O4 through the series of charge, magnetic, and structural transitions. All vibrational modes couple strongly to the charge order, whereas the LuO zone-folding modes are also sensitive to magnetic order and structural distortion. The dramatic splitting of the LuO2 layer mode is attributed to charge-rich/poor proximity effects and its temperature dependence reveals the antipolar nature of the W layer pattern.

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Tunable Band Gap In Bi(Fe1−Xmnx)O3 Films, X. S. Xu, J. F. Ihlefeld, J. H. Lee, O. K. Ezekoye, E. Vlahos, R. Ramesh, V. Gopalan, X. Q. Pan, D. G. Schlom, J. L. Musfeldt Jan 2010

Tunable Band Gap In Bi(Fe1−Xmnx)O3 Films, X. S. Xu, J. F. Ihlefeld, J. H. Lee, O. K. Ezekoye, E. Vlahos, R. Ramesh, V. Gopalan, X. Q. Pan, D. G. Schlom, J. L. Musfeldt

Xiaoshan Xu Papers

In order to investigate band gap tunability in polar oxides, we measured the optical properties of a series of Bi(Fe1−xMnx)O3 thin films. The absorption response of the mixed metal solid solutions is approximately a linear combination of the characteristics of the two end members, a result that demonstrates straightforward band gap tunability in this system.

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Magnetodielectric Coupling Of Infrared Phonons In Single-Crystal Cu2oseo3, K. H. Miller, X. S. Xu, H. Berger, E. S. Knowles, D. J. Arenas, M. W. Meisel, D. B. Tanner Jan 2010

Magnetodielectric Coupling Of Infrared Phonons In Single-Crystal Cu2oseo3, K. H. Miller, X. S. Xu, H. Berger, E. S. Knowles, D. J. Arenas, M. W. Meisel, D. B. Tanner

Xiaoshan Xu Papers

Reflection and transmission as a function of temperature (5–300 K) have been measured on a single crystal of the magnetoelectric ferrimagnetic compound Cu2OSeO3 utilizing light spanning the far infrared to the visible portions of the electromagnetic spectrum. The complex dielectric function and optical properties were obtained via Kramers-Kronig analysis and by fits to a Drude-Lortentz model. The fits of the infrared phonons show a magnetodielectric effect near the transition temperature (Tc~60 K). Assignments to strong far-infrared phonon modes have been made, especially those exhibiting anomalous behavior around the transition temperature.

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Adsorption-Controlled Growth Of Bimno3 Films By Molecular-Beam Epitaxy, J. H. Lee, X. Ke, R. Misra, J. F. Ihlefeld, X. S. Xu, Z. G. Mei, T. Heeg, M. Roeckerath, J. Schubert, Z. K. Liu, J. L. Musfeldt, P. Schiffer, D. G. Schlom Jan 2010

Adsorption-Controlled Growth Of Bimno3 Films By Molecular-Beam Epitaxy, J. H. Lee, X. Ke, R. Misra, J. F. Ihlefeld, X. S. Xu, Z. G. Mei, T. Heeg, M. Roeckerath, J. Schubert, Z. K. Liu, J. L. Musfeldt, P. Schiffer, D. G. Schlom

Xiaoshan Xu Papers

We have developed the means to grow BiMnO3 thin films with unparalleled structural perfection by reactive molecular-beam epitaxy and determined its band gap. Film growth occurs in an adsorption-controlled growth regime. Within this growth window bounded by oxygen pressure and substrate temperature at a fixed bismuth overpressure, single-phase films of the metastable perovskite BiMnO3 may be grown by epitaxial stabilization. X-ray diffraction reveals phase-pure and epitaxial films with w rocking curve full width at half maximum values as narrow as 11 arc sec (0.003°). Optical absorption measurements reveal that BiMnO3 has a direct band gap of 1.1±0.1 …

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Electrically Driven Magnetism On A Pd Thin Film, Y. Sun, John D. Burton, Evgeny Y. Tsymbal Jan 2010

Electrically Driven Magnetism On A Pd Thin Film, Y. Sun, John D. Burton, Evgeny Y. Tsymbal

Evgeny Tsymbal Publications

Using first-principles density-functional calculations, we demonstrate that ferromagnetism can be induced and modulated on an otherwise paramagnetic Pd metal thin-film surface through application of an external electric field. As free charges are either accumulated or depleted at the Pd surface to screen the applied electric field, there is a corresponding change in the surface density of states. This change can be made sufficient for the Fermi-level density of states to satisfy the Stoner criterion, driving a transition locally at the surface from a paramagnetic state to an itinerant ferromagnetic state above a critical applied electric field, Ec. Furthermore, …

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Effect Of Spin-Dependent Screening On Tunneling Electroresistance And Tunneling Magnetoresistance In Multiferroic Tunnel Junctions, M. Ye. Zhuravlev, S. Maekawa, Evgeny Y. Tsymbal Jan 2010

Effect Of Spin-Dependent Screening On Tunneling Electroresistance And Tunneling Magnetoresistance In Multiferroic Tunnel Junctions, M. Ye. Zhuravlev, S. Maekawa, Evgeny Y. Tsymbal

Evgeny Tsymbal Publications

Using a ferroelectric barrier as a functional material in a (magnetic) tunnel junction has recently attracted significant interest due to new functionalities not available in conventional tunnel junctions. Switching a ferroelectric polarization of the barrier alters conductance resulting in a tunneling electroresistance (TER) effect. Using a ferroelectric barrier in a magnetic tunnel junction makes it mutiferroic where TER coexists with tunneling magnetoresistance (TMR). Here we develop a simple model for a multiferroic tunnel junction (MFTJ) which consists of two ferromagnetic electrodes separated by a ferroelectric barrier layer. The model explicitly includes the spin-dependent screening potential and thus extends previously developed …

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Interlayer Exchange Coupling Across A Ferroelectric Barrier, M. Ye. Zhuravlev, A. V. Vedyayev, Evgeny Y. Tsymbal Jan 2010

Interlayer Exchange Coupling Across A Ferroelectric Barrier, M. Ye. Zhuravlev, A. V. Vedyayev, Evgeny Y. Tsymbal

Evgeny Tsymbal Publications

A new magnetoelectric effect is predicted originating from the interlayer exchange coupling between two ferromagnetic layers separated by an ultrathin ferroelectric barrier. It is demonstrated that ferroelectric polarization switching driven by an external electric field leads to a sizable change in the interlayer exchange coupling. The effect occurs in asymmetric ferromagnet/ferroelectric/ferromagnet junctions due to a change in the electrostatic potential profile across the junction affecting the interlayer coupling. The predicted phenomenon indicates the possibility of switching the magnetic configuration by reversing the polarization of the ferroelectric barrier layer.

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Ferroelectric Dead Layer Driven By A Polar Interface, Y. Wang, Manish K. Niranjan, K. Janicka, Julian P. Velev, Mikhail Ye Zhuravlev, Sitaram S. Jaswal, Evgeny Y. Tsymbal Jan 2010

Ferroelectric Dead Layer Driven By A Polar Interface, Y. Wang, Manish K. Niranjan, K. Janicka, Julian P. Velev, Mikhail Ye Zhuravlev, Sitaram S. Jaswal, Evgeny Y. Tsymbal

Evgeny Tsymbal Publications

Based on first-principles and model calculations we investigate the effect of polar interfaces on the ferroelectric stability of thin-film ferroelectrics. As a representative model, we consider a TiO2 -terminated BaTiO3 film with LaO monolayers at the two interfaces that serve as doping layers. We find that the polar interfaces create an intrinsic electric field that is screened by the electron charge leaking into the BaTiO3 layer. The amount of the leaking charge is controlled by the boundary conditions which are different for three heterostructures considered, namely, vacuum/LaO/BaTiO3 /LaO, LaO/BaTiO3 , and SrRuO3 /LaO/BaTiO3 …

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Evolution Of The Band Alignment At Polar Oxide Interfaces, John D. Burton, Evgeny Y. Tsymbal Jan 2010

Evolution Of The Band Alignment At Polar Oxide Interfaces, John D. Burton, Evgeny Y. Tsymbal

Evgeny Tsymbal Publications

First-principles calculations demonstrate the evolution of the band alignment at La0.7A0.3MnO3 / La1−xAxO / TiO2 / SrTiO3 (001) heterointerfaces, where A=Ca, Sr, or Ba, as the interfacial A-site composition, La1−xAx, is varied from x=0.5 to x=1.0. This variation leads to a linear change in the SrTiO3 valence-band offset with respect to the Fermi level of the La0.7A0.3MnO3 metal electrode and hence to a linear change in the Schottky barrier height at this interface. The effect arises due to electrostatic …

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Fine-Scale Genetic And Social Structuring In A Central Appalachian White-Tailed Deer Herd, Brad F. Miller, Randy W. Deyoung, Tyler A. Campbell, Benjamin R. Laseter, W. Mark Ford, Karl V. Miller Jan 2010

Fine-Scale Genetic And Social Structuring In A Central Appalachian White-Tailed Deer Herd, Brad F. Miller, Randy W. Deyoung, Tyler A. Campbell, Benjamin R. Laseter, W. Mark Ford, Karl V. Miller

United States Department of Agriculture Wildlife Services: Staff Publications

Spatial genetic structure in white-tailed deer (Odocoileus virginianus) has been examined at regional scales, but genetic markers with the resolution to detect fine-scale patterns have appeared only recently. We used a panel of microsatellite DNA markers, radiotelemetry data, and visual observations of marked deer to study fine-scale social and genetic structure in a high-density population of white-tailed deer (12–20 deer/km2). We collected genetic data on 229 adult females, 102 of which were assigned to 28 social groups. Our results were consistent with the conceptual model of white-tailed deer social structure, where philopatric females form social groups …

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Host-Specificity Of Myxoma Virus: Pathogenesis Of South American And North American Strains Of Myxoma Virus In Two North American Lagomorph Species, L. Silvers, D. Barnard, F. Knowlton, B. Inglis, A. Labudovic, M.K. Holland, P.A. Janssens, B.H. Van Leeuwen, P.J. Kerr Jan 2010

Host-Specificity Of Myxoma Virus: Pathogenesis Of South American And North American Strains Of Myxoma Virus In Two North American Lagomorph Species, L. Silvers, D. Barnard, F. Knowlton, B. Inglis, A. Labudovic, M.K. Holland, P.A. Janssens, B.H. Van Leeuwen, P.J. Kerr

United States Department of Agriculture Wildlife Services: Staff Publications

The pathogenesis of South American and North American myxoma viruses was examined in two species of North American lagomorphs, Sylvilagus nuttallii (mountain cottontail) and Sylvilagus audubonii (desert cottontail) both of which have been shown to have the potential to transmit the South American type of myxoma virus. Following infection with the South American strain (Lausanne, Lu), S. nuttallii developed both a local lesion and secondary lesions on the skin. They did not develop the classical myxomatosis seen in European rabbits (Oryctolagus cuniculus). The infection at the inoculation site did not resolve during the 20-day time course of the …

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Polyurea Elastomer Protects Utility Pole Crossarms From Damage By Pileated Woodpeckers, Shelagh Tupper, William Andelt, John Cummings, Charles Weisner, Richard Harness Jan 2010

Polyurea Elastomer Protects Utility Pole Crossarms From Damage By Pileated Woodpeckers, Shelagh Tupper, William Andelt, John Cummings, Charles Weisner, Richard Harness

United States Department of Agriculture Wildlife Services: Staff Publications

Woodpeckers cause severe damage to utility poles and crossarms, resulting in substantial economic losses to utility companies. We evaluated effectiveness of a polyurea elastomer coating material for reducing damage by captive pileated woodpeckers (Dryocopus pileatus) to utility pole crossarms. Because woodpeckers inflicted essentially no damage to the fully coated crossarms, we infer that the coating material holds substantial promise for protecting utility pole crossarms. Additional research should be conducted to evaluate the coating under field conditions.

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Evaluation Of Christmas Bird Counts And Landscape Factors As Indicators Of Local Blackbird And European Starling Winter Roosts, Matthew Strassburg, George M. Linz, William Bleier Jan 2010

Evaluation Of Christmas Bird Counts And Landscape Factors As Indicators Of Local Blackbird And European Starling Winter Roosts, Matthew Strassburg, George M. Linz, William Bleier

United States Department of Agriculture Wildlife Services: Staff Publications

Red-winged blackbirds (RWBL) and common grackles (COGR) are the two most abundant blackbird species on the continent; Brewer's blackbirds (BRBL) are a much less common, but closely related species, and along with European starlings (EUST), they are two of the most common groups of birds in North America, with combined populations that reach into the several hundreds of millions and make up a significant portion of the avian population (Yasukawa and Searcy 1995). Although the most common bird on the continent, certain regions have seen declines in RWBL for a number of decades. In Ohio and North Dakota, this has …

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Increased Risk Of Chronic Wasting Disease In Rocky Mountain Elk Associated With Decreased Magnesium And Increased Manganese In Brain Tissue, Stephen N. White, Katherine I. O’Rourke, Thomas Gidlewski, Kurt C. Vercauteren, Michelle R. Mousel, Gregory E. Phillips, Terry R. Spraker Jan 2010

Increased Risk Of Chronic Wasting Disease In Rocky Mountain Elk Associated With Decreased Magnesium And Increased Manganese In Brain Tissue, Stephen N. White, Katherine I. O’Rourke, Thomas Gidlewski, Kurt C. Vercauteren, Michelle R. Mousel, Gregory E. Phillips, Terry R. Spraker

United States Department of Agriculture Wildlife Services: Staff Publications

Chronic wasting disease (CWD) is a transmissible spongiform encephalopathy (TSE) of Rocky Mountain elk in North America. Recent studies suggest that tissue and blood mineral levels may be valuable in assessing TSE infection in sheep and cattle. The objectives of this study were to examine baseline levels of copper, manganese, magnesium, zinc, selenium, and molybdenum in the brains of Rocky Mountain elk with differing prion genotypes and to assess the association of mineral levels with CWD infection. Elk with leucine at prion position 132 had significantly lower magnesium levels than elk with 2 copies of methionine. Chronic wasting disease-positive elk …

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Review Of Issues Concerning The Use Of Reproductive Inhibitors, With Particular Emphasis On Resolving Human-Wildlife Conflicts In North America, Kathleen A. Fagerstone, Lowell A. Miller, Gary Killian, Christi A. Yoder Jan 2010

Review Of Issues Concerning The Use Of Reproductive Inhibitors, With Particular Emphasis On Resolving Human-Wildlife Conflicts In North America, Kathleen A. Fagerstone, Lowell A. Miller, Gary Killian, Christi A. Yoder

United States Department of Agriculture Wildlife Services: Staff Publications

This manuscript provides an overview of past wildlife contraception efforts and discusses the current state of research. Two fertility control agents, an avian reproductive inhibitor containing the active ingredient nicarbazin and an immunocontraceptive vaccine, have received regulatory approval with the Environmental Protection Agency and are commercially available in the USA. OvoControl G Contraceptive Bait for Canada Geese and Ovo Control for pigeons are delivered as oral baits. An injectable immunocontraceptive vaccine (GonaCon Immunocontraceptive Vaccine) was registered with the Environmental Protection Agency for use in female white-tailed deer in September 2009. An injectable product (GonaCon Immunocontraceptive Vaccine) is registered for use …

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Synchronous Monitoring Of Vulture Movements With Satellite Telemetry And Avian Radar, Robert C. Beason, J. S. Humphrey, N. E. Myers, Michael L. Avery Jan 2010

Synchronous Monitoring Of Vulture Movements With Satellite Telemetry And Avian Radar, Robert C. Beason, J. S. Humphrey, N. E. Myers, Michael L. Avery

United States Department of Agriculture Wildlife Services: Staff Publications

Radar and satellite global positioning system-platform transmitter terminal (GPSPTT) transmitters provide complementary information on the movements and behaviors of individual birds. The GPS-PTT tag provides a snapshot of altitude and location of a specific individual of an identified species at predefined intervals. The history of the individual is known because each transmitter has a unique identification code. The radar cannot identify individuals or even species but it provides continuous position reports (altitude and location) of birds within its detection range. By integrating data from the two sources, the behavior and movements of identified individuals (not possible with radar) can be …

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Seroprevalence Of Equine Influenza Virus In Northeast And Southern Mexico, B. J. Blitvitch, L. A. Ibarra-Juarez, A. J. Cortes-Guzman, J. J. Root, A. B. Franklin, H. J. Sullivan, I. Fernandez-Salas Jan 2010

Seroprevalence Of Equine Influenza Virus In Northeast And Southern Mexico, B. J. Blitvitch, L. A. Ibarra-Juarez, A. J. Cortes-Guzman, J. J. Root, A. B. Franklin, H. J. Sullivan, I. Fernandez-Salas

United States Department of Agriculture Wildlife Services: Staff Publications

Equine influenza A virus (EIV) is a highly infectious respiratory pathogen of horses (Hannant and Mumford 1996, Palese and Shaw 2007). The illness is characterised by an abrupt onset of fever, depression, coughing and nasal discharge, and is often complicated by secondary bacterial infections that can lead to pneumonia and death. Two subtypes of EIV, H3N8 and H7N7, have been isolated. The H7N7 subtype was first isolated from a horse in Czechoslovakia in 1956 (Prague/56), and the H3N8 subtype was first isolated from a horse in Miami in 1963 (Sovinova and others 1958, Waddell and others 1963). The last confirmed …

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Experimental Infection Of Raccoons (Procyon Lotor) With West Nile Virus, J. Jeffrey Root, Kevin T. Bentler, Nicole M. Nemeth, Thomas Gidlewski, Terry R. Spraker, Alan B. Franklin Jan 2010

Experimental Infection Of Raccoons (Procyon Lotor) With West Nile Virus, J. Jeffrey Root, Kevin T. Bentler, Nicole M. Nemeth, Thomas Gidlewski, Terry R. Spraker, Alan B. Franklin

United States Department of Agriculture Wildlife Services: Staff Publications

To characterize the responses of raccoons to West Nile virus (WNV) infection, we subcutaneously exposed them to WNV. Moderately high viremia titers (≤ 104.6 plaque forming units [PFU]/mL of serum) were noted in select individuals; however, peak viremia titers were variable and viremia was detectable in some individuals as late as 10 days post-inoculation (DPI). In addition, fecal shedding was prolonged in some animals (e.g., between 6 and 13 DPI in one individual), with up to105.0 PFU/fecal swab detected. West Nile virus was not detected in tissues collected on 10 or 16 DPI, and no histologic lesions attributable …

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Response Of Captive Skunks To Microencapsulated Tetracycline, Brandon S. Schmit, Thomas M. Primus, Jerome C. Hurley, Dennis J. Kohler, Shawna F. Graves Jan 2010

Response Of Captive Skunks To Microencapsulated Tetracycline, Brandon S. Schmit, Thomas M. Primus, Jerome C. Hurley, Dennis J. Kohler, Shawna F. Graves

United States Department of Agriculture Wildlife Services: Staff Publications

A captive striped skunk (Mephitis mephitis) study was conducted between February and June 2004 at the United States Department of Agriculture, Animal and Plant Health Inspection Service, Wildlife Services National Wildlife Research Center, Fort Collins, Colorado, USA. The main objective was to determine the percentage of adult striped skunks that were marked after consuming placebo oral rabies vaccine (ORV) baits containing 100 mg of an experimental microencapsulated (coated microparticle) tetracycline hydrochloride biomarker. Biomarkers were identified in the canine teeth and mandibles of five of five skunks that consumed an ORV bait. A second objective was to determine if …

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