2,353 research outputs found
The search for reasons for cross-national election behavior in Western Europe
Das folgende Papier wird zunĂ€chst darauf eingehen, daĂ die fĂŒhrenden Parteien der meisten westeuropĂ€ischen Nationen bei den Wahlen in den fĂŒnfziger und sechziger Jahren gleichzeitig WĂ€hlerkontingente gewinnen oder verlieren, unabhĂ€ngig von Ideologien, Parteistrukturen oder Kandidaten. Dann wird darauf hingewiesen, wie diese Schwankungen mit den VerĂ€nderungen im Anstieg des Pro-Kopf-Einkommens der Bewohner dieser Nationen einhergehen. SchlieĂlich wird darauf
hingewiesen, weshalb diese Analyse nur fĂŒr die fĂŒhrenden Parteien angemessen scheint. Der Autor fĂŒhrt ein Modell vor fĂŒr zukĂŒnftige Analysen von Wahlergebnissen auf nationaler Ebene und fĂŒr den internationalen Vergleich
A note on the optimality of decomposable entanglement witnesses and completely entangled subspaces
Entanglement witnesses (EWs) constitute one of the most important
entanglement detectors in quantum systems. Nevertheless, their complete
characterization, in particular with respect to the notion of optimality, is
still missing, even in the decomposable case. Here we show that for any
qubit-qunit decomposable EW (DEW) W the three statements are equivalent: (i)
the set of product vectors obeying \bra{e,f}W\ket{e,f}=0 spans the
corresponding Hilbert space, (ii) W is optimal, (iii) W=Q^{\Gamma} with Q
denoting a positive operator supported on a completely entangled subspace (CES)
and \Gamma standing for the partial transposition. While, implications
and are known, here we prove that
(iii) implies (i). This is a consequence of a more general fact saying that
product vectors orthogonal to any CES in C^{2}\otimes C^{n} span after partial
conjugation the whole space. On the other hand, already in the case of
C^{3}\otimes C^{3} Hilbert space, there exist DEWs for which (iii) does not
imply (i). Consequently, either (i) does not imply (ii), or (ii) does not imply
(iii), and the above transparent characterization obeyed by qubit-qunit DEWs,
does not hold in general.Comment: 13 pages, proof of lemma 4 corrected, theorem 3 removed, some parts
improve
Design Criteria for Zero Leakage Connectors for Launch Vehicles. Mathematical Model of Interface Sealing Phenomenon, Volume 2 Final Report
Mathematical model of interface sealing phenomenon in determining design criteria for zero leakage connectors for launch vehicle
Polarizations and Nullcone of Representations of Reductive Groups
The paper starts with the following simple observation. Let V be a representation of a reductive group G, and let f_1,f_2,...,f_n be homogeneous invariant functions. Then the polarizations of f_1,f_2,...,f_n define the nullcone of k 0} h(t) x = 0 for all x in L. This is then applied to many examples. A surprising result is about the group SL(2,C) where almost all representations V have the property that all linear subspaces of the nullcone are annihilated. Again, this has interesting applications to the invariants on several copies. Another result concerns the n-qubits which appear in quantum computing. This is the representation of a product of n copies of on the n-fold tensor product C^2 otimes C^2 otimes ... otimes C^2. Here we show just the opposite, namely that the polarizations never define the nullcone of several copies if n <= 3. (An earlier version of this paper, distributed in 2002, was split into two parts; the first part with the title ``On the nullcone of representations of reductive groups'' is published in Pacific J. Math. {bf 224} (2006), 119--140.
Field Application of a Subunit Vaccine against an Enteric Protozoan Disease
Background: Coccidiosis is a major global veterinary health problem in intensively reared chickens. It is caused by apicomplexan parasites of the genus Eimeria. Principal Findings: A subunit vaccine composed of purified antigens from the gametocytes of Eimeria maxima was used to stimulate the production and transfer of maternal antibodies between breeding hens and their hatchlings. The vaccine was injected into hens twice before they began laying eggs. Immunization had no adverse affects on egg laying or health of the hens and resulted in high antibody levels throughout the life of the hens. Progeny of immunized hens excreted significantly less oocysts of various species of Eimeria in their faeces than chicks from unvaccinated hens. Furthermore, the offspring of vaccinated hens developed stronger natural immunity to Eimeria, so that they were resistant to challenge infection even at 8 weeks of age, well after all maternal antibodies had left their circulation. Field trials were conducted in South Africa, Brazil and Thailand, involving at least 1 million progeny of vaccinated hens and at least 1 million positive control birds (raised on feed containing anticoccidial drugs or immunized with a live vaccine) in each country. Additionally, trials were carried out in Israel involving 60 million progeny of vaccinated hens and 112 million positive control birds. There were no significant differences in growth rate, feed conversion ratios or mortality in the offspring of vaccinated hens compared with the positive control chickens in any of these countries regardless of different management practices, different breeds of chickens or climate. Conclusions: These results demonstrate that a vaccine composed of antigens purified from the gametocytes of Eimeria can be used safely and effectively to prevent the deleterious effects of coccidiosis. It is the first subunit vaccine against any protozoan parasite to be successfully applied on a commercial scale. © 2008 Wallach et al
Simple Space-Time Symmetries: Generalizing Conformal Field Theory
We study simple space-time symmetry groups G which act on a space-time
manifold M=G/H which admits a G-invariant global causal structure. We classify
pairs (G,M) which share the following additional properties of conformal field
theory: 1) The stability subgroup H of a point in M is the identity component
of a parabolic subgroup of G, implying factorization H=MAN, where M generalizes
Lorentz transformations, A dilatations, and N special conformal
transformations. 2) special conformal transformations in N act trivially on
tangent vectors to the space-time manifold M. The allowed simple Lie groups G
are the universal coverings of SU(m,m), SO(2,D), Sp(l,R), SO*(4n) and E_7(-25)
and H are particular maximal parabolic subgroups. They coincide with the groups
of fractional linear transformations of Euklidean Jordan algebras whose use as
generalizations of Minkowski space time was advocated by Gunaydin. All these
groups G admit positive energy representations. It will also be shown that the
classical conformal groups SO(2,D) are the only allowed groups which possess a
time reflection automorphism; in all other cases space-time has an intrinsic
chiral structure.Comment: 37 pages, 4 Table
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