4,686 research outputs found
The effect of diatomaceous earth in live, attenuated infectious bronchitis vaccine, immune responses, and protection against challenge.
Live virus vaccines are commonly used in poultry production, particularly in broilers. Massive application and generation of a protective local mucosal and humoral immunity with no adverse effects is the main goal for this strategy. Live virus vaccines can be improved by adding adjuvants to boost mucosal innate and adaptive responses. In a previous study we showed that diatomaceous earth (DE) can be used as adjuvant in inactivated vaccines. The aim of this study was to test DE as adjuvant in an Ark-DPI live infectious bronchitis virus (IBV) vaccine after ocular or spray application. Titrating the virus alone or after addition of DE showed that DE had no detrimental effect on the vaccine virus. However, adding DE to the vaccine did not induce higher IgG titers in the serum and IgA titers in tears. It also did not affect the frequency of CD4+ T cells, CD8+ T cells and monocytes/macrophages in the blood and the spleen determined by flow cytometry. In addition, protection generated against IBV homologous challenges, measured by viral load in tears, respiratory signs and histopathology in tracheas, did not vary when DE was present in the vaccine formulation. Finally, we confirmed through our observations that Ark vaccines administered by hatchery spray cabinet elicit weaker immune responses and protection against an IBV homologous challenge compared to the same vaccine delivered via ocular route
Nonaxisymmetric MHD instabilities of Chandrasekhar states in Taylor-Couette geometry
We consider axially periodic Taylor-Couette geometry with insulating boundary
conditions. The imposed basic states are so-called Chandrasekhar states, where
the azimuthal flow and magnetic field have the same radial
profiles. Mainly three particular profiles are considered: the Rayleigh limit,
quasi-Keplerian, and solid-body rotation. In each case we begin by computing
linear instability curves and their dependence on the magnetic Prandtl number
Pm. For the azimuthal wavenumber m=1 modes, the instability curves always scale
with the Reynolds number and the Hartmann number. For sufficiently small Pm
these modes therefore only become unstable for magnetic Mach numbers less than
unity, and are thus not relevant for most astrophysical applications. However,
modes with m>10 can behave very differently. For sufficiently flat profiles,
they scale with the magnetic Reynolds number and the Lundquist number, thereby
allowing instability also for the large magnetic Mach numbers of astrophysical
objects. We further compute fully nonlinear, three-dimensional equilibration of
these instabilities, and investigate how the energy is distributed among the
azimuthal (m) and axial (k) wavenumbers. In comparison spectra become steeper
for large m, reflecting the smoothing action of shear. On the other hand
kinetic and magnetic energy spectra exhibit similar behavior: if several
azimuthal modes are already linearly unstable they are relatively flat, but for
the rigidly rotating case where m=1 is the only unstable mode they are so steep
that neither Kolmogorov nor Iroshnikov-Kraichnan spectra fit the results. The
total magnetic energy exceeds the kinetic energy only for large magnetic
Reynolds numbers Rm>100.Comment: 12 pages, 14 figures, submitted to Ap
Anisotropic turbulence in weakly stratified rotating magnetoconvection
Numerical simulations of the 3D MHD-equations that describe rotating
magnetoconvection in a Cartesian box have been performed using the code
NIRVANA. The characteristics of averaged quantities like the turbulence
intensity and the turbulent heat flux that are caused by the combined action of
the small-scale fluctuations are computed. The correlation length of the
turbulence significantly depends on the strength and orientation of the
magnetic field and the anisotropic behavior of the turbulence intensity induced
by Coriolis and Lorentz force is considerably more pronounced for faster
rotation. The development of isotropic behavior on the small scales -- as it is
observed in pure rotating convection -- vanishes even for a weak magnetic field
which results in a turbulent flow that is dominated by the vertical component.
In the presence of a horizontal magnetic field the vertical turbulent heat flux
slightly increases with increasing field strength, so that cooling of the
rotating system is facilitated. Horizontal transport of heat is always directed
westwards and towards the poles. The latter might be a source of a large-scale
meridional flow whereas the first would be important in global simulations in
case of non-axisymmetric boundary conditions for the heat flux.Comment: 13 pages 11 figure
Parity properties of an advection-dominated solar \alpha^2\Om-dynamo
We have developed a high-precision code which solves the kinematic dynamo
problem both for given rotation law and meridional flow in the case of a low
eddy diffusivity of the order of cm/s known from the sunspot
decay. All our models work with an \alf-effect which is positive (negative) in
the northern (southern) hemisphere. It is concentrated in radial layers located
either at the top or at the bottom of the convection zone. We have also
considered an \alf-effect uniformly distributed in all the convection zone. In
the present paper the main attention is focused on i) the parity of the
solution, ii) the form of the butterfly diagram and iii) the phase relation of
the resulting field components. If the helioseismologically derived internal
solar rotation law is considered, a model without meridional flow of high
magnetic Reynolds number (corresponding to low eddy diffusivity) fails in all
the three issues in comparison with the observations. However, a meridional
flow with equatorial drift at the bottom of the convection zone of few meters
by second can indeed enforce the equatorward migration of the toroidal magnetic
field belts similar to the observed butterfly diagram but, the solution has
only a dipolar parity if the (positive) \alf-effect is located at the base of
the convection zone rather than at the top. We can, therefore, confirm the main
results of a similar study by Dikpati & Gilman (2001).Comment: 9 pages, 16 figures, to appear on Astronomy and Astrophysic
Lambda-effect from forced turbulence simulations
Aims: We determine the components of the -effect tensor that
quantifies the contributions to the turbulent momentum transport even for
uniform rotation. Methods: Three-dimensional numerical simulations are used to
study turbulent transport in triply periodic cubes under the influence of
rotation and anisotropic forcing. Comparison is made with analytical results
obtained via the so-called minimal tau-approximation. Results: In the case
where the turbulence intensity in the vertical direction dominates, the
vertical stress is always negative. This situation is expected to occur in
stellar convection zones. The horizontal component of the stress is weaker and
exhibits a maximum at latitude 30 degrees - regardless of how rapid the
rotation is. The minimal tau-approximation captures many of the qualitative
features of the numerical results, provided the relaxation time tau is close to
the turnover time, i.e. the Strouhal number is of order unity.Comment: 20 pages, 14 figures, accepted for publication in Astronomy &
Astrophysic
Myocutane und fasciocutane freie LAppen zur Defektdeckung am Unterschenkel und Fuß
Verglichen werden freie myocutane Lappenplastiken, wie der
Latissimus dorsi-Lappen, der Gracilis-Lappen und der untere Gluteallappen, sowie
fasciocutane Lappen, wie der Scapularlappen in ihrer Anwendung zur Defektdeckung
an Unterschenkel und Fuß.
Es zeigte sich, daß myocutane Lappen eher geeignet sind tiefe Defekte mit Knochenverlusten
zu füllen, sie stellen ein gutes Lager für eine Spongiosaplastik dar. Fasciocutane
Lappen eignen sich eher zur Deckung flächiger Defekte. Sie zeigen auch ohne
Muskulatur eine gute Durchblutung durch das epifasciale Gefäßnetz. Sie sind dünner
als myocutane Lappen und benötigen bei großen Defekten an der Empfängerzone
keine zusätzliche Spalthauttransplantation
Experimental demonstration of higher-order Laguerre-Gauss mode interferometry
The compatibility of higher-order Laguerre-Gauss (LG) modes with
interferometric technologies commonly used in gravitational wave detectors is
investigated. In this paper we present the first experimental results
concerning the performance of the LG33 mode in optical resonators. We show that
the Pound-Drever-Hall error signal for a LG33 mode in a linear optical
resonator is identical to that of the more commonly used LG00 mode, and
demonstrate the feedback control of the resonator with a LG33 mode. We
succeeded to increase the mode purity of a LG33 mode generated using a
spatial-light modulator from 51% to 99% upon transmission through a linear
optical resonator. We further report the experimental verification that a
triangular optical resonator does not transmit helical LG modes
A Simple Algorithm for Local Conversion of Pure States
We describe an algorithm for converting one bipartite quantum state into
another using only local operations and classical communication, which is much
simpler than the original algorithm given by Nielsen [Phys. Rev. Lett. 83, 436
(1999)]. Our algorithm uses only a single measurement by one of the parties,
followed by local unitary operations which are permutations in the local
Schmidt bases.Comment: 5 pages, LaTeX, reference adde
Conditions for compatibility of quantum state assignments
Suppose N parties describe the state of a quantum system by N possibly
different density operators. These N state assignments represent the beliefs of
the parties about the system. We examine conditions for determining whether the
N state assignments are compatible. We distinguish two kinds of procedures for
assessing compatibility, the first based on the compatibility of the prior
beliefs on which the N state assignments are based and the second based on the
compatibility of predictive measurement probabilities they define. The first
procedure leads to a compatibility criterion proposed by Brun, Finkelstein, and
Mermin [BFM, Phys. Rev. A 65, 032315 (2002)]. The second procedure leads to a
hierarchy of measurement-based compatibility criteria which is fundamentally
different from the corresponding classical situation. Quantum mechanically none
of the measurement-based compatibility criteria is equivalent to the BFM
criterion.Comment: REVTEX 4, 19 pages, 1 postscript figur
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