I would like to thank students of the Paris Team and Guillaume Cambray, instructor, for their participation to the talks.
Thanks to people I exchange with about these concerns, especially Dorothée Benoît Browaeys from Vivagora and Dominique Pestre my Director at the Centre Alexandre Koyré, Ecole des Hautes Etudes en Science Sociales.
Thanks to François Le Fevre for his precious help in the final rush before the wiki freeze.
Nothing could be possible without the help of Christina Agapakis for her clever look on my work, for her precious corrections and comments.
Special thanks too for Nicola Bullard for her help and corrections in the last rush.
My last special thanks are going to Frank Dehu for his presence, comments and support during my study.