Bauschinger effect in thin metallic films by fem simulations

Unpassivated free-standing gold and aluminum thin films (thickness ~ 200-400 nm, mean grain size dm,Au≈ 70-80nm, dm,Al≈ 120-200nm), subjected to tensile tests show Bauschinger effect (BE) during unloading [1, 2]. The focus of this work is to investigate the effect of microstructural heterogeneity such as grain sizes on the BE and the macroscopic deformation behavior in thin metallic films. The finite element code LAGAMINE is used to model the response of films involving sets of grains with different strengths. The numerical results are compared with experimental results from tensile tests on aluminum thin films from the work of Rajagopalan, et al. [2]

PlantRNA, a database for tRNAs of photosynthetic eukaryotes.

International audiencePlantRNA database (http://plantrna.ibmp.cnrs.fr/) compiles transfer RNA (tRNA) gene sequences retrieved from fully annotated plant nuclear, plastidial and mitochondrial genomes. The set of annotated tRNA gene sequences has been manually curated for maximum quality and confidence. The novelty of this database resides in the inclusion of biological information relevant to the function of all the tRNAs entered in the library. This includes 5'- and 3'-flanking sequences, A and B box sequences, region of transcription initiation and poly(T) transcription termination stretches, tRNA intron sequences, aminoacyl-tRNA synthetases and enzymes responsible for tRNA maturation and modification. Finally, data on mitochondrial import of nuclear-encoded tRNAs as well as the bibliome for the respective tRNAs and tRNA-binding proteins are also included. The current annotation concerns complete genomes from 11 organisms: five flowering plants (Arabidopsis thaliana, Oryza sativa, Populus trichocarpa, Medicago truncatula and Brachypodium distachyon), a moss (Physcomitrella patens), two green algae (Chlamydomonas reinhardtii and Ostreococcus tauri), one glaucophyte (Cyanophora paradoxa), one brown alga (Ectocarpus siliculosus) and a pennate diatom (Phaeodactylum tricornutum). The database will be regularly updated and implemented with new plant genome annotations so as to provide extensive information on tRNA biology to the research community

Nanomechanical Characterization of the Deformation Response of Orthotropic Ti–6Al–4V

The nanoindentation‐induced mechanical deformation response is applied to identify the orthotropic elastic moduli using the Delafargue and Ulm method as well as to validate the asymmetric orthotropic CPB06 nonlinear plasticity model required in simulations of nonuniform macroscopic mechanical response of the Ti–6Al–4V alloy. Scanning electron microscope (SEM) technique allows to select the maximum penetration depth for the indentation in the deformed alpha phase and alpha–beta interphase, α and α/β, respectively. The apparent macromechanical response can be successfully derived from several residual imprints conducted at micro‐ and/or submicrometric length scale and distributed throughout samples of the investigated bulk alloy, as demonstrated by correlation with finite element simulations based on the orthotropic elastoplastic model. The accurate numerical response obtained validates the material model and the Delafargue and Ulm approach, opening a window for next generation identification methods of macromechanical plasticity models with hybrid experimental–numerical method based on instrumented indentation and the use of SEM technique

Applying FAIR Principles to plant phenotypic data management in GnpIS

GnpIS is a data repository for plant phenomics that stores whole field and greenhouse experimental data including environment measures. It allows long-term access to datasets following the FAIR principles: Findable, Accessible, Interoperable, and Reusable, by using a flexible and original approach. It is based on a generic and ontology driven data model and an innovative software architecture that uncouples data integration, storage, and querying. It takes advantage of international standards including the Crop Ontology, MIAPPE, and the Breeding API. GnpIS allows handling data for a wide range of species and experiment types, including multiannual perennial plants experimental network or annual plant trials with either raw data, i.e., direct measures, or computed traits. It also ensures the integration and the interoperability among phenotyping datasets and with genotyping data. This is achieved through a careful curation and annotation of the key resources conducted in close collaboration with the communities providing data. Our repository follows the Open Science data publication principles by ensuring citability of each dataset. Finally, GnpIS compliance with international standards enables its interoperability with other data repositories hence allowing data links between phenotype and other data types. GnpIS can therefore contribute to emerging international federations of information systems

Multiscale modelling of back-stress during equal-channel angular pressing

Equal-channel angular pressing (ECAP) is a well known process to produce ultrafine-grained materials. The mechanical properties of these materials, including a compression-tension asymmetry and a transient hardening saturation in the beginning of the flow curve, largely depend on the evolution of the microstructure during ECAP. Consequently, the back-stress induced by the dislocation microstructure exhibits kinematic hardening at the macroscopic scale. In this paper, commercial purity aluminium AA1050 is processed by ECAP route C. Tensile and compression specimens are machined from the post-ECAP samples. The back-stress level is estimated from the different yielding strengths of tensile tests and compression tests. Then two different models, a macroscopic phenomenological Teodosiu-type model and a microscopic dislocation-based multi-layer model, are used to predict the back-stress values. A set of parameters for Teodosiu's model is identified from simple shear tests, Bauschinger tests and orthogonal tests. The dislocation-based multi-layer model is based on the Estrin-Toth dislocation model and Sauzay's intragranular back-stress model. The predicted and experimental back-stresses due to ECAP are compared and critically evaluated.status: publishe

Vpliv različnih kombinacij cepič/podlaga na lastnosti pridelka sorte `Cabernet sauvignon`

Unpassivated free-standing gold and aluminum thin films (thickness ~ 200-400 nm, mean grain size dm,Au≈ 70-80nm, dm,Al≈ 120-200nm), subjected to tensile tests show Bauschinger effect (BE) during unloading [1, 2]. The focus of this work is to investigate the effect of microstructural heterogeneity such as grain sizes on the BE and the macroscopic deformation behavior in thin metallic films. The finite element code LAGAMINE is used to model the response of films involving sets of grains with different strengths. The numerical results are compared with experimental results from tensile tests on aluminum thin films from the work of Rajagopalan, et al. [2]

The interactome of CLUH reveals its association to SPAG5 and its co-translational proximity to mitochondrial proteins

International audienceBackground: Mitochondria require thousands of proteins to fulfill their essential function in energy production and other fundamental biological processes. These proteins are mostly encoded by the nuclear genome, translated in the cytoplasm before being imported into the organelle. RNA binding proteins (RBPs) are central players in the regulation of this process by affecting mRNA translation, stability, or localization. CLUH is an RBP recognizing specifically mRNAs coding for mitochondrial proteins, but its precise molecular function and interacting partners remain undiscovered in mammals. Results: Here we reveal for the first time CLUH interactome in mammalian cells. Using both co-IP and BioID proximity-labeling approaches, we identify novel molecular partners interacting stably or transiently with CLUH in HCT116 cells and mouse embryonic stem cells. We reveal stable RNA-independent interactions of CLUH with itself and with SPAG5 in cytosolic granular structures. More importantly, we uncover an unexpected proximity of CLUH to mitochondrial proteins and their cognate mRNAs in the cytosol. We show that this interaction occurs during the process of active translation and is dependent on CLUH TPR domain. Conclusions: Overall, through the analysis of CLUH interactome, our study sheds a new light on CLUH molecular function by revealing new partners and by highlighting its link to the translation and subcellular localization of some mRNAs coding for mitochondrial proteins

A global picture of tRNA genes in plant genomes

Although transfer RNA (tRNA) has a fundamental role in cell life, little is known about tRNA gene organization and expression on a genome-wide scale in eukaryotes, particularly plants. Here, we analyse the content and distribution of tRNA genes in five flowering plants and one green alga. The tRNA gene content is homogenous in plants, and is mostly correlated with genome size. The number of tRNA pseudogenes and organellar-like tRNA genes present in nuclear genomes varies greatly from one plant species to another. These pseudogenes or organellar-like genes appear to be generated or inserted randomly during evolution. Interestingly, we identified a new family of tRNA-related short interspersed nuclear elements (SINEs) in the Populus trichocarpa nuclear genome. In higher plants, intron-containing tRNA genes are rare, and correspond to genes coding for tRNATyr and tRNAMete. By contrast, in green algae, more than half of the tRNA genes contain an intron. This suggests divergent means of intron acquisition and the splicing process between green algae and land plants. Numerous tRNAs are co-transcribed in Chlamydomonas, but they are mostly transcribed as a single unit in flowering plants. The only exceptions are tRNAGly–snoRNA and tRNAMete–snoRNA cotranscripts in dicots and monocots, respectively. The internal or external motifs required for efficient transcription of tRNA genes by RNA polymerase III are well conserved among angiosperms. A brief analysis of the mitochondrial and plastidial tRNA gene populations is also provided