Analysis of LhcSR3, a Protein Essential for Feedback De-Excitation in the Green Alga Chlamydomonas reinhardtii

To prevent photodamage by excess light, plants use different proteins to sense pH changes and to dissipate excited energy states. In green microalgae, however, the LhcSR3 gene product is able to perform both pH sensing and energy quenching functions

Dynamic Secure Aspect Modeling with UML: From Models to Code

Abstract. Security engineering deals with modeling, analysis, and implementation of complex security mechanisms. The dynamic nature of such mechanisms makes it difficult to anticipate undesirable emergent behavior. In this work, we propose an approach to develop and analyze security-critical specifications and implementations using aspect-oriented modeling. Since we focus on the dynamic views of a system, our work is complementary to existing approaches to security aspects mostly concerned with static views. Our approach includes a link to implementations in so far as the code which is constructed from the models can be analyzed automatically for satisfaction of the security requirements stated in the UML diagrams. We present tool support for our approach.

Computing in the Presence of Concurrent Solo Executions

International audienceIn a wait-free model any number of processes may crash. A process runs solo when it computes its local output without receiving any information from other processes, either because they crashed or they are too slow. While in wait-free shared-memory models at most one process may run solo in an execution, any number of processes may have to run solo in an asynchronous wait-free message-passing model.This paper is on the computability power of models in which several processes may concurrently run solo. It first introduces a family of round-based wait-free models, called the d-solo models, 1 ≤ d ≤ n, where up to d processes may run solo. The paper gives then a characterization of the colorless tasks that can be solved in each d-solo model. It also introduces the (d,ε)-solo approximate agreement task, which generalizes ε-approximate agreement, and proves that (d,ε)-solo approximate agreement can be solved in the d-solo model, but cannot be solved in the (d + 1)-solo model. The paper studies also the relation linking d-set agreement and (d,ε)-solo approximate agreement in asynchronous wait-free message-passing systems.These results establish for the first time a hierarchy of wait-free models that, while weaker than the basic read/write model, are nevertheless strong enough to solve non-trivial tasks