Multiphysics modeling and optimization of mechatronic multibody systems

peer reviewedModeling mechatronic multibody systems requires the same type of methodology as for designing and prototyping mechatronic devices: a unified and integrated engineering approach. Various formulations are currently proposed to deal with multiphysics modeling, e.g., graph theories, equational approaches, co-simulation techniques. Recent works have pointed out their relative advantages and drawbacks, depending on the application to deal with: model size, model complexity, degree of coupling, frequency range, etc. This paper is the result of a close collaboration between three laboratories, and aims at showing that for "non-academic" mechatronic applications (i.e., issuing from real industrial issues), multibody dynamics formulations can be generalized to mechatronic systems, for the model generation as well as for the numerical analysis phases. Model portability being also an important aspect of the work, they must be easily interfaced with control design and optimization programs. A global "demonstrator", based on an industrial case, is discussed: multiphysics modeling and mathematical optimization are carried out to illustrate the consistency and the efficiency of the proposed approaches

mRNA Translation: Fungal Variations on a Eukaryotic Theme

The accurate transfer of information from a nucleotide-based code to a protein-based one is at the heart of all life processes. The actual information transfer occurs during protein synthesis or translation, and is catalysed by ribosomes, supported by a large host of additional protein activities—the translation factors. This chapter reviews how the different eukaryotic initiation, elongation and termination factors assist the ribosome in establishing appropriate contacts with mRNAs during translation initiation, decode the genetic code during translation elongation, and finally release the newly made polypeptide and reuse the ribosomes during the termination and recycling phases

A Novel Conserved RNA-binding Domain Protein, RBD-1, Is Essential For Ribosome Biogenesis

Synthesis of the ribosomal subunits from pre-rRNA requires a large number of trans-acting proteins and small nucleolar ribonucleoprotein particles to execute base modifications, RNA cleavages, and structural rearrangements. We have characterized a novel protein, RNA-binding domain-1 (RBD-1), that is involved in ribosome biogenesis. This protein contains six consensus RNA-binding domains and is conserved as to sequence, domain organization, and cellular location from yeast to human. RBD-1 is essential in Caenorhabditis elegans. In the dipteran Chironomus tentans, RBD-1 (Ct-RBD-1) binds pre-rRNA in vitro and anti-Ct-RBD-1 antibodies repress pre-rRNA processing in vivo. Ct-RBD-1 is mainly located in the nucleolus in an RNA polymerase I transcription-dependent manner, but it is also present in discrete foci in the interchromatin and in the cytoplasm. In cytoplasmic extracts, 20–30% of Ct-RBD-1 is associated with ribosomes and, preferentially, with the 40S ribosomal subunit. Our data suggest that RBD-1 plays a role in structurally coordinating pre-rRNA during ribosome biogenesis and that this function is conserved in all eukaryotes

Alternative mechanisms of mRNA translationiInitiation in cellular stress response and cancer

Throughout evolution, eukaryotic cells have devised different mechanisms to cope with stressful environments. When eukaryotic cells are exposed to stress stimuli, they activate adaptive pathways that allow them to restore cellular homeostasis. Most types of stress stimuli have been reported to induce a decrease in overall protein synthesis accompanied by induction of alternative mechanisms of mRNA translation initiation. Here, we present well-studied and recent examples of such stress responses and the alternative translation initiation mechanisms they induce, and discuss the consequences of such regulation for cell homeostasis and oncogenic transformation.Marco M Candeias was partially supported by grants PTDC/MED-ONC/32048/2017 and PTDC/BIMONC/4890/2014 from Fundação para a Ciência e a Tecnologia (FCT), by Grants-in-Aid 16K21111 and 18K07229 from the Ministry of Education, Culture, Sports, Science and Technology (MEXT) of Japan, by Takeda Foundation and Astellas Foundation. Juliane Menezes is a posdoc fellow (SFRH/BPD/98360/2013) from FCT.info:eu-repo/semantics/publishedVersio