Selected papers

Here is the list of some selected papers. These four papers are in biology but in different fields: cellular dynamics, gene networks, hair growth and collective decision in animal groups. Diverse as it appears, there is nevertheless a common underlying research theme: from individual capabilities to collective behavior through "socia" interactions.

José Halloy, Jean-Marc Amé, Colette Rivault, Claire Detrain and Jean-Louis Deneubourg (2006). Collegial decision making based on social amplification leads to optimal group formation. Proc Natl Acad Sci USA 2006 1003: 5835-5840 published online before print as 10;1073/pnas.0507877103.

Gonze D., Halloy J., and Goldbeter A. (2002) Robustness of circadian rhythms with respect to molecular noise. Proc Natl Acad Sci USA 99, 673-678.

Halloy J., Bernard B.A., Loussouarn G., and Goldbeter A. (2000) Modeling the dynamics of human hair cycles by a follicular automaton. Proc Natl Acad Sci USA 97, 8328-8333.

Lauzeral J., Halloy J., and Goldbeter A. (1997) Desynchronization of cells on the developmental path triggers the formation of spiral waves of cAMP during Dictyostelium aggregation. Proc Natl Acad Sci USA 94, 9153-9158.

The paper in 1997, deals with the wave pattern formed during D. discoideum aggregation. This cellular system presents a striking transition from unicellular to multicellular life. It presents mathematical modeling and computer simulation of the signalling and aggregation phase in the life cycle of D.d. The hypothesis presented makes a possible link between cellular variablility and collective pattern fromation.

In 2000, the paper is about hair growth life cycle. Human hair presents a life cycle with 3 main phases i.e. growth (anagen), stationary (telogen) and decay and death (absence of hair). Hair cycling is an impressive model for developemtal biology and in particular in human skin organ regeneration.The paper considers the role of the length of these phases and their dynamics in the global pattern of hair in male human and its link with baldness. The paper includes experimental data analysis, mathematical modeling and computer simulation. It has been done in collaboration with L’Oréal and also incorporated in a patent.

In 2002, the paper deals with the role of molecular noise in a genetic network producing circadian rhythms. It uses mathematical modeling and computer simulations.The question addressed concerns the robustness of limit cycle oscillations when the number of molecules is very low. This paper is also a response to the question raised by Barkai and Leibler in Nature 2000 Jan 20;403(6767):267-8.

In 2006, the paper is about collective decision making in gregarious insects. The paper combines experiments, data analysis, mathematical modeling and computer simulation. It proposes a model base on simple hypothesis that explains in quantitative terms how group of cockroaches (B. germanica) choose between resting shelters. The decision is self-organized and all individual are equal..