Universal Features for the Classification of Coding and Non-coding DNA Sequences

In this report, we revisited simple features that allow the classification of coding sequences (CDS) from non-coding DNA. The spectrum of codon usage of our sequence sample is large and suggests that these features are universal. The features that we investigated combine (i) the stop codon distribution, (ii) the product of purine probabilities in the three positions of nucleotide triplets, (iii) the product of Cytosine, Guanine, Adenine probabilities in 1st, 2nd, 3rd position of triplets, respectively, (iv) the product of G and C probabilities in 1st and 2nd position of triplets. These features are a natural consequence of the physico-chemical properties of proteins and their combination is successful in classifying CDS and non-coding DNA (introns) with a success rate >95% above 350 bp. The coding strand and coding frame are implicitly deduced when the sequences are classified as coding

Time-dependent strain-tuning topological magnon phase transition

Collinear magnets in honeycomb lattices under the action of time-dependent strains are investigated. Given the limits of high-frequency periodically varying deformations, we derive an effective Floquet theory for spin system that results in the emergence of a spin chirality. We find that the coupling between magnons and spin chirality depends on the details of the strain such as the spatial dependence and applied direction. Magnonic fluctuations about the ferromagnetic state are determined, and it is found that spatially homogeneous strains drive the magnon system into topologically protected phases. In particular, we show that certain uniform strain fields play the role of an out-of-plane next-neighbor Dzyaloshinskii-Moriya interaction. Furthermore, we explore the application of nonuniform strains, which lead to a confinement of magnon states that for uniaxial strains, propagates along the direction that preserves translational symmetry. Our work demonstrates a direct and novel way in which to manipulate the magnon spectrum based on time-dependent strain engineering that is relevant for exploring topological transitions in quantum magnonics

OPTIMISATION OF A DRIVE SYSTEM AND ITS EPICYCLIC GEAR SET

International audienceThis paper describes the design of a drive consisting of a DC motor, a speed reducer, a lead screw transformation system, a power converter and its associated DC source. The objective is to reduce the mass of the system. Indeed, the volume and weight optimisation of an electrical drive is an important issue for embedded applications. Here, we present an analytical model of the system in a specific application and afterwards an optimisation of the motor and speed reducer main dimensions and the battery voltage in order to reduce the weight

Multi objective optimisation of an electromagnetic valve actuator

International audienceThis paper is about a modelling and an optimisation of an electromechanical drive system. The device consists of a DC source, a power converter, a linear actuator and its load. The aim of the system is to drive a load along a linear displacement. The two main objectives are to reduce the actuator volume and the copper losses, which are contrary objectives. Here, we present an analytical modelling of the system and afterwards an optimisation of the linear actuator main dimensions in order to carry out the previous objectives

Optimal design of a wound rotor synchronous generator using genetic algorithm

International audienceThe manufacturers are tempted to reduce the amount of active materials in the devices in order to lower the material bill. However, reducing the weight of the devices directly affects the energy efficiency. In this paper, a solution to this problem is proposed for the case of synchronous wound rotor generators. The trade-off between cost and efficiency is formulated as a constrained optimization problem and solved using a Genetic Algorithm. The cost optimization of three different machines is carried out through various design approaches. The proposed approach always gives better results than the classical approach concerning the global cost of the range

Diseases of the reared honeybee Apis mellifera l.

The reared honeybee Apis mellifera L. is a major social insect because of its productions, and more importantly because of its action on crop pollination. The health of honeybees has becomes a real challenge in the past decade, with colony weakening and/or losses caused by environmental, chemical or biological factors. Recent research suggests a synergistic effect between pathogens. Therefore, veterinary clinicians trained in beekeeping pathology and veterinarians responsible for food safety play a major role in these issues.L’abeille d’élevage Apis mellifera L. est un insecte social majeur par ses productions et plus encore, par son rôle dans la pollinisation des cultures. Sa santé est devenue un véritable défi : les affaiblissements et/ou les pertes de colonies observés depuis plus d’une décennie peuvent résulter de maladies favorisées par des facteurs environnementaux, chimiques et biologiques. Les recherches récentes tendent à montrer l’action synergique des agents pathogènes. Dans ce cadre, les vétérinaires cliniciens formés en pathologie apicole et ceux chargés de la sécurité sanitaire des aliments, ont toute leur place