A Process Calculus for Dynamic Networks

In this paper we propose a process calculus framework for dynamic networks in which the network topology may change as computation proceeds. The proposed calculus allows one to abstract away from neighborhood-discovery computations and it contains features for broadcasting at multiple transmission ranges and for viewing networks at different levels of abstraction. We develop a theory of confluence for the calculus and we use the machinery developed towards the verification of a leader-election algorithm for mobile ad hoc networks

Parameterized Verification of Safety Properties in Ad Hoc Network Protocols

We summarize the main results proved in recent work on the parameterized verification of safety properties for ad hoc network protocols. We consider a model in which the communication topology of a network is represented as a graph. Nodes represent states of individual processes. Adjacent nodes represent single-hop neighbors. Processes are finite state automata that communicate via selective broadcast messages. Reception of a broadcast is restricted to single-hop neighbors. For this model we consider a decision problem that can be expressed as the verification of the existence of an initial topology in which the execution of the protocol can lead to a configuration with at least one node in a certain state. The decision problem is parametric both on the size and on the form of the communication topology of the initial configurations. We draw a complete picture of the decidability and complexity boundaries of this problem according to various assumptions on the possible topologies.Comment: In Proceedings PACO 2011, arXiv:1108.145

In-house issues with family farming

Publication disponible en ligne à l'adresse URL suivante : http://www.agropolis.org/pdf/publications/proceedings-international-encounters-family-farming-research-june-2014.pdfInternational audienc

Phosphorylation of SRC-family lck tyrosine kinase following IL-12 activation of human NK cells

Interleukin-12 (IL-12) is a heterodimeric cytokine that augments the cytolytic activity of human NK cells and T cells but has little mitogenic activity on resting lymphocytes. The intracellular signaling pathways involved in NK cell activation by IL-12 have not been fully characterized. In the present studies we found that IL-12 induces tyrosine phosphorylation of a 56-kDa protein, identified in Western blot experiments as p56lck, in resting NK cells. IL-12 was active in the range of 0.1 to 1000 U/ml, with maximal activity between 10 and 100 U/ml (30 and 300 pM). The maximal effect was noted 5 min after stimulation and was almost completely inhibited by genistein. IL-12 induced similar effects in resting and IL-2 activated NK cells. Following IL-12 stimulation of resting NK cells, immunoprecipitated lck kinase exhibited increased in vitro autophosphorylation activity 5 and 10 min after activation. Several additional substrates were phosphorylated in vitro following IL-12 stimulation, including proteins of 70 and 110 kDa. These studies indicate that lck tyrosine kinase is involved in the IL-12 signaling pathway in human NK cells. As the primary functional effect of IL-12 on resting NK cells is the enhancement of cytolytic activity and secretory function rather than cell proliferation, these findings suggest that lck tyrosine kinase is involved in these signaling pathways in human NK cells