Mutations in the Mitochondrial Methionyl-tRNA Synthetase Cause a Neurodegenerative Phenotype in Flies and a Recessive Ataxia (ARSAL) in Humans

The study of Drosophila neurodegenerative mutants combined with genetic and biochemical analyses lead to the identification of multiple complex mutations in 60 patients with a novel form of ataxia/leukoencephalopathy

High gain observer-based fault estimation for nonlinear networked control systems

In this paper, an observer-based fault estimation (FE) method is presented for a class of nonlinear networked control systems (NCSs) with Markov transfer delays. First, the nonlinear NCSs are modelled by nonlinear discrete Takagi- Sugeno (T-S) fuzzy model with modelling uncertainty. Under some geometric conditions, the proposed nonlinear T-S model can be transformed into two subsystems with one of them having backstepping form. Then, the discrete nonlinear observer is designed to provide the estimation of unmeasurable state and the modelling uncertainty, which is used to construct a fault estimation algorithm. Finally, an example is included to show the efficiency of the proposed method. Index Terms-Nonlinear networked control systems, Takagi- Sugeno fuzzy model, fault estimation, observer.Zehui Mao, Bin Jiang, Peng Shi, and Vincent Cocquempo

Optimal design of dependable control system architectures using temporal sequences of failures

Designing a dependable control system requires accurate methods to evaluate efficiently the dependability level of one given component architecture. This evaluation is crucial to determine the risks associated with system failures, and the remaining properties after fault occurrences. The dependability level of a control system depends not only on the kind of component failures that may occur, but also on the ordered sequences of the failure appearance. Classical evaluation methods, i.e. Fault Trees or Failure Mode and Effect Analysis, are not appropriate to handle these sequences. Our paper contributes on this aspect, and proposes a complete design methodology for dependable systems. This methodology uses ordered sequences of multiple failures to evaluate accurately the dependability level of all possible system's equipment architectures. Starting with the hierarchical functional decomposition of the system, the first step is to identify the dreaded events. Thus, the faulty behaviors of all possible system architectures are characterized with temporal operators. The set of system's operational architectures is finally determined by solving an optimization problem that considers both dependability objectives, and cost constraints. This methodology is applied to design a fire detection system for a railroad transportation system. In this paper, a complete methodology to design dependable control systems is presented. The innovative feature of this methodology is that it attempts to take into account time ordered sequences of failures. A new representation, called improved multi-fault tree, is defined. This tool allows us first to model failure relationships between functions, and second to evaluate the dependability level of a set of equipment architectures by the use of time ordered sequences of failures. Our design method provides a set of optimal architectures with given costs, and dependability levels. The designer can choose among these solutions tradin- g among the costs, and dependability level specifications. The comparison between the new approach and the classical dependability method shows that the set of solutions for the multi-fault tree is smaller than the set of solutions for the classical one. The set is smaller, but the solutions are better because the new approach integrates temporal functions, and evaluates more precisely the level of dependability than with the traditional one

Observer-Based Fault Estimation for Networked Control Systems with Transfer Delays

In this paper, diagnosis of actuator/component faults for networked control systems (NCSs) with transfer delays is investigated. First, the linear NCSs with transfer delays are modelled by T-S discrete-time systems with input delays. Next, under certain conditions, a stable adaptive observer for fault diagnosis is designed. An extension to a class of nonlinear systems is then made. Finally, a motor example is given to illustrate the e±ciency of the proposed method.Ze hui Mao, Bin Jiang, Vincent Cocquempot, Peng Sh

: First interception of the cerambycid beetle Stromatium longicorne (Newman, 1842) in Belgium and distribution notes on other species of Stromatium (Coleoptera: Cerambycidae: Cerambycinae)

National audienceDans cet article, un récapitulatif de la distribution des cinq espèces composant le genre Stromatium Audinet-Serville est présenté et la première interception de Stromatium longicorne (Newman, 1842) en Belgique est signalée. Cette capture est présentée et commentée