Hommage à André Raynauld

Hommage to reactive psychosis.

When looking back in the history of psychiatry, the concept of reactivity had very variable impact on ethiological considerations. If classification of mental disorders is taken as a proxy, it seems that this impact is presently at the lowest that it has been in the last hundred years. The author gives a short historical overview of concept of reactive psychosis, followed by a description of th...

A conjecture of Yves André . ∗

The introduction to [2] (and references contained therein) contains a comprehensive exposition of terminology and notations relative to this conjecture. Since we use the same terminology and notations, we do not reproduce them here. The introduction to [2] also contains an exposition of results on this conjecture obtained before the article [3] came out. In this article we prove the following t...

François Bach and André Herbelin

Reals which Compute Little André

We investigate combinatorial lowness properties of sets of natural numbers (reals). The real A is super-low if A′ ≤tt ∅′, and A is jump-traceable if the values of {e}A(e) can be effectively approximated in a sense to be specified. We investigate those properties, in particular showing that super-lowness and jump-traceability coincide within the r.e. sets but none of the properties implies the o...

André Skupin and Sara Irina Fabrikant

s (Kohonen et al. 1999). Spring models are another popular category of dimensionality reduction techniques (Kamada and Kawai 1989, Skupin and Fabrikant 2003). Pathfinder network scaling (PFN) is a technique used for network visualization, with a preservation of the most salient links between input features. It is frequently applied to citation networks (Chen and Paul 2001). To illustrate this, ...