293 research outputs found
Some new monogenean species and genera of the family Mazocraeidae
The morphological peculiarities of the Mazocraeidae, in particular the clamp structures, are discussed and a Latin nomenclature for the elements of the clamp skeleton is suggested. 3 new genera and 6 new species are then describe
Dissipative stabilization of entangled cat states using a driven Bose-Hubbard dimer
We analyze a modified Bose-Hubbard model, where two cavities having on-site
Kerr interactions are subject to two-photon driving and correlated dissipation.
We derive an exact solution for the steady state of this interacting
driven-dissipative system, and use it show that the system permits the
preparation and stabilization of pure entangled non-Gaussian states, so-called
entangled cat states. Unlike previous proposals for dissipative stabilization
of such states, our approach requires only a linear coupling to a single
engineered reservoir (as opposed to nonlinear couplings to two or more
reservoirs). Our scheme is within the reach of state-of-the-art experiments in
circuit QED.Comment: 5 pages main text, 5 pages appendices, 6 figure
Superconducting Accelerating RF-Structure Stability at a High Energy Level from the Point of View of Thermal Balance
Chromosome Abnormalities and Hematopoietic Stem Cell Transplantation in Acute Leukemias
The chapter considers specific treatment options, including allogeneic hematopoietic stem cell transplantation (allo‐HSCT) in acute myeloid leukemia (AML) and acute lymphoblastic leukemia (ALL), in patients with some prognostically proven cytogenetic variants as monosomal ones, complex and hyperdiploid karyotypes, like chromosomal translocations t(v;11)(v;q23), t(3;3)/inv(3); t(8;21), t(9;22), etc. Important prognostic role of additional chromosome abnormalities was shown for the patients with t(8;21) and t(9;22). Hence, it is evident that allo‐HSCT in patients with poor risk cytogenetic variant must be performed as early as possible, i.e., during first complete remission
Attractive Casimir Forces in a Closed Geometry
We study the Casimir force acting on a conducting piston with arbitrary cross
section. We find the exact solution for a rectangular cross section and the
first three terms in the asymptotic expansion for small height to width ratio
when the cross section is arbitrary. Though weakened by the presence of the
walls, the Casimir force turns out to be always attractive. Claims of repulsive
Casimir forces for related configurations, like the cube, are invalidated by
cutoff dependence.Comment: An updated version to coincide with the one published December 2005
in PRL. 4 pages, 2 figure
Strain-Compensated AlInGaAs-GaAsP Superlattices for Highly-Polarized Electron Emission
Spin-polarized electron emission from the first superlattice photocathodes
developed with strain compensation is investigated. An opposite strain in the
quantum well and barrier layers is complished using an InAlGaAs/GaAsP
superlattice structure. The measured values of maximum polarization and quantum
yield for the structure with a 0.18 um-thick working layer are close to the
best results reported for any strained superlattice photocathode structure,
demonstrating the high potential of strain compensation for future photocathode
applications. An analysis of the photoemission spectra is used to estimate the
parameters responsible for the polarization losses.Comment: 10 pages, 2 figure
The graceful exit from the anomaly-induced inflation: Supersymmetry as a key
The stable version of the anomaly-induced inflation does not need a fine
tuning and leads to sufficient expansion of the Universe. The non-stable
version (Starobinsky model) provides the graceful exit to the FRW phase. We
indicate the possibility of the inflation which is stable at the beginning and
unstable at the end. The effect is due to the soft supersymmetry breaking and
the decoupling of the massive sparticles at low energy.Comment: 10 pages, 2 figures using axodraw. Modified version. Discussion
concerning the gravitational scale modified, the effect of massive particles
in the last stage of inflation taken into accoun
Svortices and the fundamental modes of the "snake instability": Possibility of observation in the gaseous Bose-Einstein Condensate
The connection between quantized vortices and dark solitons in a long and
thin, waveguide-like trap geometry is explored in the framework of the
non-linear Schr\"odinger equation. Variation of the transverse confinement
leads from the quasi-1D regime where solitons are stable to 2D (or 3D)
confinement where soliton stripes are subject to a transverse modulational
instability known as the ``snake instability''. We present numerical evidence
of a regime of intermediate confinement where solitons decay into single,
deformed vortices with solitonic properties, also called svortices, rather than
vortex pairs as associated with the ``snake'' metaphor. Further relaxing the
transverse confinement leads to production of 2 and then 3 vortices, which
correlates perfectly with a Bogoliubov-de Gennes stability analysis. The decay
of a stationary dark soliton (or, planar node) into a single svortex is
predicted to be experimentally observable in a 3D harmonically confined dilute
gas Bose-Einstein condensate.Comment: 4 pages, 4 figure
DeWitt-Schwinger Renormalization and Vacuum Polarization in d Dimensions
Calculation of the vacuum polarization, , has seen a recent resurgence, notably
for black hole spacetimes. To date, most calculations of this type have been
done only in four dimensions. Extending these calculations to dimensions
includes -dimensional renormalization. Typically, the renormalizing terms
are found from Christensen's covariant point splitting method for the
DeWitt-Schwinger expansion. However, some manipulation is required to put the
correct terms into a form that is compatible with problems of the vacuum
polarization type. Here, after a review of the current state of affairs for
calculations and a thorough introduction to
the method of calculating and for certain spacetimes is discussed, with application to four and
five dimensions.Comment: 21 pages, 2 tables, 3 figures. References added, rewritten to clarify
some points, corrections performed, our claim in the first version that there
is an error in Anderson's calculations is incorrec
Watching dark solitons decay into vortex rings in a Bose-Einstein condensate
We have created spatial dark solitons in two-component Bose-Einstein
condensates in which the soliton exists in one of the condensate components and
the soliton nodal plane is filled with the second component. The filled
solitons are stable for hundreds of milliseconds. The filling can be
selectively removed, making the soliton more susceptible to dynamical
instabilities. For a condensate in a spherically symmetric potential, these
instabilities cause the dark soliton to decay into stable vortex rings. We have
imaged the resulting vortex rings.Comment: 4 pages, 4 figure
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