1,450 research outputs found
Survey of occurrence in meatâproducing rabbitries in Switzerland
Background: An outbreak of salmonellosis due to Salmonella Typhimurium was detected coincidentally in a Swiss meat rabbitry, given that surveillance of Salmonella in rabbits is not mandatory in Switzerland.
Methods: To assess the extent of potentially subclinical Salmonella carriage in meat rabbits, faecal pool samples of 50 farms (90% of Swiss commercial rabbitries) with ground covering litter and group housing were bacteriologically tested. Additionally, 236 rabbits showing clinical signs compatible with intestinal diseases, such as salmonellosis, were examined postmortem and analysed bacteriologically. Salmonella isolates were serotyped and analysed by whole genome sequencing (WGS).
Results: Salmonella Typhimurium was detected in three commercial farms (6.0% of all tested farms). The affected farms were directly linked to the animal trade and Salmonella isolates were shown to be identical by WGS.
Conclusion: There is no increased hazard for Salmonella carriage in the animal welfare-friendly Swiss husbandry systems in general, despite risk factors such as ground covering litter
Intersection rules, dynamics and symmetries
We consider theories containing gravity, at most one dilaton and form field
strengths. We show that the existence of particular BPS solutions of
intersecting extremal closed branes select the theories, which upon dimensional
reduction to three dimensions possess a simple simply laced Lie group symmetry
G. Furthermore these theories can be fully reconstructed from the dynamics of
such branes and of their openings. Amongst such theories are the effective
actions of the bosonic sector of M-theory and of the bosonic string. The BPS
intersecting brane solutions form representations of a subgroup of the group of
Weyl reflections and outer automorphisms of the triple Kac-Moody extension G+++
of the G algebra, which cannot be embedded in the overextended Kac-Moody
subalgebra G++ characterising the cosmological Kasner solutions.Comment: Latex 30 pages, 3 figure
Constraints on Automorphic Forms of Higher Derivative Terms from Compactification
By dimensionally reducing the higher derivative corrections of
ten-dimensional IIB theory on a torus we deduce constraints on the E_{n+1}
automorphic forms that occur in d=10-n dimensions. In particular we argue that
these automorphic forms involve the representation of E_{n+1} with fundamental
weight \lambda^{n+1}, which is also the representation to which the string
charges in d dimensions belong. We also consider a similar calculation for the
reduction of higher derivative terms in eleven-dimensional M-theory.Comment: Minor corrections, to appear in JHE
Higher derivative type II string effective actions, automorphic forms and E11
By dimensionally reducing the ten-dimensional higher derivative type IIA
string theory effective action we place constraints on the automorphic forms
that appear in the effective action in lower dimensions. We propose a number of
properties of such automorphic forms and consider the prospects that E11 can
play a role in the formulation of the higher derivative string theory effective
action.Comment: 34 page
Irreducible Hamiltonian BRST analysis of Stueckelberg coupled p-form gauge theories
The irreducible Hamiltonian BRST symmetry for p-form gauge theories with
Stueckelberg coupling is derived. The cornerstone of our approach is
represented by the construction of an irreducible theory that is equivalent
from the point of view of the BRST formalism with the original system. The
equivalence makes permissible the substitution of the BRST quantization of the
reducible model by that of the irreducible theory. Our procedure maintains the
Lorentz covariance of the irreducible path integral.Comment: 29 pages, LaTeX 2.0
Solution--Generating Transformations and the String Effective Action
We study exhaustively the solution-generating transformations (dualities)
that occur in the context of the low-energy effective action of superstring
theory. We first consider target-space duality (``T duality'') transformations
in absence of vector fields. We find that for one isometry the full duality
group is (SO^{\uparrow}(1,1))^{3} x D_{4}, the discrete part (D_{4}) being
non-Abelian. We, then, include non-Abelian Yang--Mills fields and find the
corresponding generalization of the T duality transformations. We study the
\alpha^{\prime} corrections to these transformations and show that the T
duality rules considerably simplify if the gauge group is embedded in the
holonomy group. Next, in the case in which there are Abelian vector fields, we
consider the duality group that includes the transformation introduced by Sen
that rotates among themselves components of the metric, axion and vector field.
Finally we list the duality symmetries of the Type II theories with one
isometry.Comment: latex file, 42 pages (less if you use optional commands) No changes
at all. Resubmited due to mailer problem
N=8 BPS Black Holes with 1/2 or 1/4 Supersymmetry and Solvable Lie Algebra Decompositions
In the context of N=8 supergravity we construct the general form of BPS
0--branes that preserve either 1/2 or 1/4 of the original supersymmetry. We
show how such solutions are related to suitable decompositions of the 70
dimensional solvable Lie algebra that describes the scalar field sector. We
compare our new results to those obtained in a previous paper for the case of
1/8 supersymmetry preserving black holes. Each of the three cases is based on a
different solvable Lie algebra decomposition and leads to a different structure
of the scalar field evolution and of their fixed values at the horizon of the
black hole.Comment: first section restructured, typos corrected, 1 LaTeX file, 37 pages,
2 eps-figure
SO(10) Cosmic Strings and SU(3) Color Cheshire Charge
Certain cosmic strings that occur in GUT models such as can carry a
magnetic flux which acts nontrivially on objects carrying
quantum numbers. We show that such strings are non-Abelian Alice strings
carrying nonlocalizable colored ``Cheshire" charge. We examine claims made in
the literature that strings can have a long-range, topological
Aharonov-Bohm interaction that turns quarks into leptons, and observe that such
a process is impossible. We also discuss flux-flux scattering using a
multi-sheeted formalism.Comment: 37 Pages, 8 Figures (available upon request) phyzzx, iassns-hep-93-6,
itp-sb-93-6
The SARS-coronavirus-host interactome
Coronaviruses (CoVs) are important human and animal pathogens that induce fatal respiratory, gastrointestinal and neurological disease. The outbreak of the severe acute respiratory syndrome (SARS) in 2002/2003 has demonstrated human vulnerability to (Coronavirus) CoV epidemics. Neither vaccines nor therapeutics are available against human and animal CoVs. Knowledge of host cell proteins that take part in pivotal virus-host interactions could define broad-spectrum antiviral targets. In this study, we used a systems biology approach employing a genome-wide yeast-two hybrid interaction screen to identify immunopilins (PPIA, PPIB, PPIH, PPIG, FKBP1A, FKBP1B) as interaction partners of the CoV non-structural protein 1 (Nsp1). These molecules modulate the Calcineurin/NFAT pathway that plays an important role in immune cell activation. Overexpression of NSP1 and infection with live SARS-CoV strongly increased signalling through the Calcineurin/NFAT pathway and enhanced the induction of interleukin 2, compatible with late-stage immunopathogenicity and long-term cytokine dysregulation as observed in severe SARS cases. Conversely, inhibition of cyclophilins by cyclosporine A (CspA) blocked the replication of CoVs of all genera, including SARS-CoV, human CoV-229E and -NL-63, feline CoV, as well as avian infectious bronchitis virus. Non-immunosuppressive derivatives of CspA might serve as broad-range CoV inhibitors applicable against emerging CoVs as well as ubiquitous pathogens of humans and livestock
E11, generalised space-time and equations of motion in four dimensions
We construct the non-linear realisation of the semi-direct product of E11 and
its first fundamental representation at low levels in four dimensions. We
include the fields for gravity, the scalars and the gauge fields as well as the
duals of these fields. The generalised space-time, upon which the fields
depend, consists of the usual coordinates of four dimensional space-time and
Lorentz scalar coordinates which belong to the 56-dimensional representation of
E7. We demand that the equations of motion are first order in derivatives of
the generalised space-time and then show that they are essentially uniquely
determined by the properties of the E11 Kac-Moody algebra and its first
fundamental representation. The two lowest equations correctly describe the
equations of motion of the scalars and the gauge fields once one takes the
fields to depend only on the usual four dimensional space-time
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