Research of the origin of a particular Tunisian group using a physical marker and Alu insertion polymorphisms

The aim of this study was to show how, in some particular circumstances, a physical marker can be used along with molecular markers in the research of an ancient people movement. A set of five Alu insertions was analysed in 42 subjects from a particular Tunisian group (El Hamma) that has, unlike most of the Tunisian population, a very dark skin, similar to that of sub-Saharans, and in 114 Tunisian subjects (Gabes sample) from the same governorate, but outside the group. Our results showed that the El Hamma group is genetically midway between sub-Saharan populations and North Africans, whereas the Gabes sample is clustered among North Africans. In addition, The A25 Alu insertion, considered characteristic to sub-Saharan Africans, was present in the El Hamma group at a relatively high frequency. This frequency was similar to that found in sub-Saharans from Nigeria, but significantly different from those found in the Gabes sample and in other North African populations. Our molecular results, consistent with the skin color status, suggest a sub-Saharan origin of this particular Tunisian group

Logical foundations for reasoning about transformations of knowledge bases

This paper is about transformations of knowledge bases with the aid of an imperative programming language which is non-standard in the sense that it features conditions (in loops and selection statements) that are description logic (DL) formulas, and a non-deterministic assignment statement (a choice operator given by a DL formula). We sketch an operational semantics of the proposed programming language and then develop a matching Hoare calculus whose pre- and post-conditions are again DL formulas. A major difficulty resides in showing that the formulas generated when calculating weakest preconditions remain within the chosen DL fragment. In particular, this concerns substitutions whose result is not directly representable. We therefore explicitly add substitution as a constructor of the logic and show how it can be eliminated by an interleaving with the rules of a traditional tableau calculu