1,986 research outputs found
The GL-l.u.st.\ constant and asymmetry of the Kalton-Peck twisted sum in finite dimensions
We prove that the Kalton-Peck twisted sum of -dimensional Hilbert
spaces has GL-l.u.st.\ constant of order and bounded GL constant. This
is the first concrete example which shows different explicit orders of growth
in the GL and GL-l.u.st.\ constants. We discuss also the asymmetry constants of
Fragmentation of chloroplast coupling factor in dependence of bound nucleotides Preparation of a reconstitutionally active form of subunit δ
AbstractPrevious studies on the ability of CF1, fragments to reconstitute photophosphorylation in CF1,-depleted thylakoids have shown that the degree of reconstitution was correlated with the presence of subunit δ in the fragment. This was taken as evidence that subunit δ was necessary for plugging the active proton channel CF0 [(1986) Eur. J. Biochem. 160, 635â643]. We questioned whether or not δ alone had this ability. In order to obtain δ we investigated the role of bound nucleotides in the stability of CF1. Starting from ammonium sulfate-precipitated CF1, we found that a low content of bound ADP (1 mol ADP/mol CF1) seemed to stabilize the βâδ interaction, while loosening the interaction between Îą,β and Îł. By elution from an anion-exchange column in the presence of the nonionic surfactant Mega 9 we obtained β3δ and CF1(âδ) (both containing one ADP) or, after washing with alcohol/glycerol mixtures, β (nucleotide-free) and CF1/CF1(âĎľ). On the other hand, with a further 2 ADP and 2 ATP bound to CF1, (after incubation with excess ATP) the Îą-β-Îł interaction was stabilized in such a way that subunit δ alone could be isolated from the complex. Subunit δ, when isolated by this procedure and added back to CF1-depleted thylakoids, reconstituted a high rate of photophosphorylation
Large violation of Bell inequalities with low entanglement
In this paper we obtain violations of general bipartite Bell inequalities of
order with inputs, outputs and
-dimensional Hilbert spaces. Moreover, we construct explicitly, up to a
random choice of signs, all the elements involved in such violations: the
coefficients of the Bell inequalities, POVMs measurements and quantum states.
Analyzing this construction we find that, even though entanglement is necessary
to obtain violation of Bell inequalities, the Entropy of entanglement of the
underlying state is essentially irrelevant in obtaining large violation. We
also indicate why the maximally entangled state is a rather poor candidate in
producing large violations with arbitrary coefficients. However, we also show
that for Bell inequalities with positive coefficients (in particular, games)
the maximally entangled state achieves the largest violation up to a
logarithmic factor.Comment: Reference [16] added. Some typos correcte
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Catalytic hydrogenation of carboxylic acid esters, amides, and nitriles with homogeneous catalysts
This review describes the catalytic reduction of amides, carboxylic acid esters and nitriles with homogeneous catalysts using molecular hydrogen as an environmental friendly reducing agent
Connes' embedding problem and Tsirelson's problem
We show that Tsirelson's problem concerning the set of quantum correlations
and Connes' embedding problem on finite approximations in von Neumann algebras
(known to be equivalent to Kirchberg's QWEP conjecture) are essentially
equivalent. Specifically, Tsirelson's problem asks whether the set of bipartite
quantum correlations generated between tensor product separated systems is the
same as the set of correlations between commuting C*-algebras. Connes'
embedding problem asks whether any separable II factor is a subfactor of
the ultrapower of the hyperfinite II factor. We show that an affirmative
answer to Connes' question implies a positive answer to Tsirelson's.
Conversely, a positve answer to a matrix valued version of Tsirelson's problem
implies a positive one to Connes' problem
Measurement, model testing, and legislative influence in the European Union
Within the last several years, new data have become available to test the various theoretical models of EU decision-making, and, in doing so, to assess actor influence. This article examines the extent to which the recent DEU and DEUII datasets provide sufficient information to distinguish between competing theoretical models of legislative decision-making, and accurately assess the power of the different branches of EU government. It argues that insufficient attention has been paid to measurement error in these data. Once measurement error is accounted for, it becomes clear that these data do not provide sufficient information to distinguish between most models of legislative politics. Moreover, empirical models that fail to account for measurement error are likely to lead researchers to erroneous conclusions about actorsâ legislative influence. </jats:p
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