1,832 research outputs found
Fisrt report of indigenous Dermacentor reticulatus populations in Belgium and preliminary study on associated Babesiosis pathogens
An explicit formula for the Berezin star product
We prove an explicit formula of the Berezin star product on Kaehler
manifolds. The formula is expressed as a summation over certain strongly
connected digraphs. The proof relies on a combinatorial interpretation of
Englis' work on the asymptotic expansion of the Laplace integral.Comment: 19 pages, to appear in Lett. Math. Phy
Influence of nonlocal electrodynamics on the anisotropic vortex pinning in
We have studied the pinning force density Fp of YNi_2B_2C superconductors for
various field orientations. We observe anisotropies both between the c-axis and
the basal plane and within the plane, that cannot be explained by usual mass
anisotropy. For magnetic field , the reorientation structural
transition in the vortex lattice due to nonlocality, which occurs at a field
, manifests itself as a kink in Fp(H). When , Fp is
much larger and has a quite different H dependence, indicating that other
pinning mechanisms are present. In this case the signature of nonlocal effects
is the presence of a fourfold periodicity of Fp within the basal plane.Comment: 4 pages, 3 figure
Gymnosperms from the Early Cretaceous Crato Formation (Brazil). II. Cheirolepidiaceae
Conifers are common in the Early Cretaceous Crato flora. Sterile foliage shoots of several morphotypes occur. Good preservation of several of these specimens allows detailed morphological and anatomical studies. Based on these characters, two taxa of Cheirolepidiaceae, Tomaxellia biforme and Frenelopsis sp., are identified. The palaeogeographic distribution of the genus Tomaxellia currently extends from southern South America northwards to the palaeoequatorial region. The morphological and anatomical characters of both taxa might be interpreted as adaptations to a warm and temporarily dry palaeoclimate, however their habitat can not be reconstructed yet, due to scarcity of the remains.
Koniferen stellen eine wesentliche Komponente der unterkretazischen Crato-Flora dar. Es kommen sterile beblätterte Zweige verschiedener Morphotypen vor. Die gute Erhaltung einiger dieser Fossilreste lässt detaillierte morphologisch-anatomische Untersuchungen zu. Auf der Basis solcher Merkmale wurden zwei Taxa der Cheirolepidiaceae, Tomaxellia biforme und Frenelopsis sp., identifiziert. Das Areal der Gattung Tomaxellia wird damit vom südlichen Südamerika nordwärts, in die paläoäquatoriale Region erweitert. Morphologische und anatomische Merkmale beider Taxa können als Anpassungserscheinungen an ein warmes und periodisch trockenes Paläoklima interpretiert werden. Auf Grund des seltenen Vorkommens solcher Fossilreste können noch keine Angaben zu ihrem ehemaligen Habitat gemacht werden.
doi:10.1002/mmng.200600009</a
From dispersionless to soliton systems via Weyl-Moyal like deformations
The formalism of quantization deformation is reviewed and the Weyl-Moyal like
deformation is applied to systematic construction of the field and lattice
integrable soliton systems from Poisson algebras of dispersionless systems.Comment: 26 page
A study of the superconducting gap in RNiBC (R = Y, Lu) single crystals by inelastic light scattering
Superconductivity-induced changes in the electronic Raman scattering response
were observed for the RNiBC (R = Y, Lu) system in different scattering
geometries. In the superconducting state, 2-like peaks were observed in
A, B, and B spectra from single crystals. The peaks in
A and B symmetries are significantly sharper and stronger than
the peak in B symmetry. The temperature dependence of the frequencies of
the 2-like peaks shows typical BCS-type behavior, but the apparent
values of the gap are strongly anisotropic for both systems. In
addition, for both YNiBC and LuNiBC systems, there exists
reproducible scattering strength below the gap which is roughly
linear to the frequency in B and B symmetries. This discovery of
scattering below the gap in non-magnetic borocarbide superconductors, which are
thought to be conventional BCS-type superconductors, is a challenge for current
understanding of superconductivity in this system.Comment: Added text, changed a figure, and added references. Will appear in
Phys. Rev.
Four-fold basal plane anisotropy of the nonlocal magnetization of YNi2B2C
Studies of single crystal YNi2B2C have revealed a four-fold anisotropy of the
equilibrium magnetization in the square crystallographic basal plane. This pi/2
periodicity occurs deep in the superconductive mixed state. In this crystal
symmetry, an ordinary superconductive mass anisotropy (as in usual London
theory) allows only a constant, isotropic response. In contrast, the
experimental results are well described by generalized London theory
incorporating non-local electrodynamics, as needed for this clean,
intermediate-k superconductor.Comment: 4 pages, 4 figure
Equilibrium basal-plane magnetization of superconductive YNi(2)B(2)C - the influence of non-local electrodynamics
For a single crystal of YNi(2)B(2)C superconductor, the equilibrium
magnetization M in the square basal plane has been studied experimentally as a
function of temperature and magnetic field. While the magnetization M(H)
deviates from conventional London predictions, a recent extension of London
theory (to include effects of non-local electrodynamics) describes the
experiments accurately. The resulting superconductive parameters are well
behaved. These results are compared with corresponding findings for the case
with M perpendicular to the basal plane.Comment: 7 pages, 5 Postscript Figures, 2 table
Who are the long-QT syndrome patients who receive an implantable cardioverter-defibrillator and what happens to them?: data from the European Long-QT Syndrome Implantable Cardioverter-Defibrillator (LQTS ICD) Registry.
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