The aim of this paper is to investigate the variety of symmetric closure algebras, that is, closure algebras endowed with a De Morgan operator. Some general properties are derived. Particularly, the lattice of subvarieties of the subvariety of monadic symmetric algebras is described and an equational basis for each subvariety is given.

In this paper we prove that the free pseudocomplemented residuated lattices are decomposable if and only if they are Stone, i.e., if and only if they satisfy the identity ¬ x ∨ ¬¬ x = 1. Some applications are given.

In this paper we extend Mundici’s functor Γ to the category of monadic MV-algebras. More precisely, we define monadic ℓ -groups and we establish a natural equivalence between the category of monadic MV-algebras and the category of monadic ℓ -groups with strong unit. Some applications are given thereof.

This paper is devoted to the study of some subvarieties of the variety Qof Q-Heyting algebras, that is, Heyting algebras with a quantifier. In particular, a deeper investigation is carried out in the variety Q 3 of three-valued Q-Heyting algebras to show that the structure of the lattice of subvarieties of Qis far more complicated that the lattice of subvarieties of Heyting algebras. We determine the simple and subdirectly irreducible algebras in Q 3 and we construct the lattice of subvarieties (...) (Q 3 ) of the variety Q 3. (shrink)

This paper is devoted to the study of some subvarieties of the variety Q of Q-Heyting algebras, that is, Heyting algebras with a quantifier. In particular, a deeper investigation is carried out in the variety Q subscript 3 of three-valued Q-Heyting algebras to show that the structure of the lattice of subvarieties of Q is far more complicated that the lattice of subvarieties of Heyting algebras. We determine the simple and subdirectly irreducible algebras in Q subscript 3 and we construct (...) the lattice of subvarieties lambda (Q subscript 3) of the variety Q subscript 3. (shrink)

There is a constructive method to define a structure of simple k -cyclic Post algebra of order p , L p , k , on a given finite field F ( p k ), and conversely. There exists an interpretation Φ 1 of the variety $${\mathcal{V}(L_{p,k})}$$ generated by L p , k into the variety $${\mathcal{V}(F(p^k))}$$ generated by F ( p k ) and an interpretation Φ 2 of $${\mathcal{V}(F(p^k))}$$ into $${\mathcal{V}(L_{p,k})}$$ such that Φ 2 Φ 1 ( B ) (...) = B for every $${B \in \mathcal{V}(L_{p,k})}$$ and Φ 1 Φ 2 ( R ) = R for every $${R \in \mathcal{V}(F(p^k))}$$. In this paper we show how we can solve an algebraic system of equations over an arbitrary cyclic Post algebra of order p, p prime, using the above interpretation, Gröbner bases and algorithms programmed in Maple. (shrink)

In this paper we study some questions concerning Łukasiewicz implication algebras. In particular, we show that every subquasivariety of Łukasiewicz implication algebras is, in fact, a variety. We also derive some characterizations of congruence permutable algebras. The starting point for these results is a representation of finite Łukasiewicz implication algebras as upwardly-closed subsets in direct products of MV-chains.

Data taken by the Mark II detector at the PEP storage ring was used to measure the rate of dilepton production in multihadronic events produced by e+e- annihilation at √s=29 GeV. We determine the probability that a hadron initially containing a b quark decays to a positive lepton to be 0.17-0.08+0.15, with 90% confidence level limits of 0.06 and 0.38. © 1990.

We present an experimental test of the validity of the Pauli Exclusion Principle for electrons based on the concept put forward a few years ago by Ramberg and Snow. In this experiment we perform a very accurate search of X-rays from the Pauli-forbidden atomic transitions of electrons in the already filled 1S shells of copper atoms. Although the experiment has a simple structure, it poses deep conceptual and interpretational problems. Here we describe the experimental method and recent experimental results, which (...) we interpret as an upper limit for the probability to violate the Pauli Exclusion Principle. We present also future plans to upgrade the experimental apparatus using Silicon Drift Detectors. (shrink)

Objectives: To foster the development of a privacy-protective, sustainable cross-border information system in the framework of a European public health project. Materials and methods: A targeted privacy impact assessment was implemented to identify the best architecture for a European information system for diabetes directly tapping into clinical registries. Four steps were used to provide input to software designers and developers: a structured literature search, analysis of data flow scenarios or options, creation of an ad hoc questionnaire and conduction of a (...) Delphi procedure. Results: The literature search identified a core set of relevant papers on privacy. Technicians envisaged three candidate system architectures, with associated data flows, to source an information flow questionnaire that was submitted to the Delphi panel for the selection of the best architecture. A detailed scheme envisaging an “aggregation by group of patients” was finally chosen, based upon the exchange of finely tuned summary tables. Conclusions: Public health information systems should be carefully engineered only after a clear strategy for privacy protection has been planned, to avoid breaching current regulations and future concerns and to optimise the development of statistical routines. The BIRO project delivers a specific method of privacy impact assessment that can be conveniently used in similar situations across Europe. (shrink)

In this paper we describe an experimental test of the validity of the Pauli Exclusion Principle (for electrons) which is based on a straightforward idea put forward a few years ago by Ramberg and Snow (Phys. Lett. B 238:438, 1990). We perform a very accurate search of X-rays from the Pauli-forbidden atomic transitions of electrons in the already filled 1S shells of copper atoms. Although the experiment has a very simple structure, it poses deep conceptual and interpretational problems. Here we (...) describe the experimental method and recent experimental results, which we interpret in the framework of quon theory. We also present future plans to upgrade the experimental apparatus using Silicon Drift Detectors. (shrink)

We present the idea of searching for X-rays as a signature of the mechanism inducing the spontaneous collapse of the wave function. Such a signal is predicted by the continuous spontaneous localization theories, which are solving the “measurement problem” by modifying the Schrödinger equation. We will show some encouraging preliminary results and discuss future plans and strategy.

We use data from the Mark II experiment at PEP to search for the process B→h0X for mh0 between 50 and 210 MeV/c2. No evidence for the Higgs boson is seen in this mass range. The limit obtained rules out the standard Higgs boson for masses between 70 and 210 MeV/c2 and significantly constrains extensions of the Higgs sector. © 1989.