Définition d'une famille de patrons de transformation pour l'analyse de modèles AADL

AADL (Architecture Analysis and Design Language) est un langage de description d'architecture permettant une multitude d'analyses formelles ou semi-formelles, en utilisant par exemple des analyses statiques ou, encore, des techniques de model-checking. AADL fournit un niveau d'abstraction intéressant pour exprimer de nombreuses constructions utiles à la réalisation de systèmes embarqués temps réel. Parallèlement, nous remarquons que les propriétés à vérifier sur ces systèmes ne couvrent bien souvent qu'un sous-ensemble des éléments du modèle (composants ou propriétés non-fonctionnelles). Dans le présent article il est montré comment tirer parti de ces informations pour définir plusieurs patrons de transformation d'AADL vers les réseaux de Petri adaptés à la propriété à vérifier. Les propriétés qualitatives du système (comme la détection d'interblocage ou la traçabilité des messages échangés) peuvent être analysées à l'aide des réseaux de Petri colorés, en utilisant l'environnement CPN-AMI. Les propriétés quantitatives (comme l'ordonnancement du système ou la vérification du dimensionnement des tampons de communication) peuvent être traitées à l'aide des réseaux de Petri temporels, en utilisant l'environnement Tina. Les auteurs se sont intéressés à l'élaboration de patrons génériques pouvant être annotés en accord avec le type de propriété à traiter; ils montrent comment ces patrons permettent de limiter l'explosion combinatoire en restreignant le modèle à analyser aux seuls blocs utiles

The Arabidopsis pop2-1 mutant reveals the involvement of GABA transaminase in salt stress tolerance

<p>Abstract</p> <p>Background</p> <p>GABA (γ-aminobutyric acid) is a non protein amino acid that has been reported to accumulate in a number of plant species when subjected to high salinity and many other environmental constraints. However, no experimental data are to date available on the molecular function of GABA and the involvement of its metabolism in salt stress tolerance in higher plants. Here, we investigated the regulation of GABA metabolism in <it>Arabidopsis thaliana </it>at the metabolite, enzymatic activity and gene transcription levels upon NaCl stress.</p> <p>Results</p> <p>We identified the GABA transaminase (GABA-T), the first step of GABA catabolism, as the most responsive to NaCl. We further performed a functional analysis of the corresponding gene <it>POP2 </it>and demonstrated that the previously isolated loss-of-function <it>pop2-1 </it>mutant was oversensitive to ionic stress but not to osmotic stress suggesting a specific role in salt tolerance. NaCl oversensitivity was not associated with overaccumulation of Na⁺and Cl^-but mutant showed a slight decrease in K⁺. To bring insights into <it>POP2 </it>function, a promoter-reporter gene strategy was used and showed that <it>POP2 </it>was mainly expressed in roots under control conditions and was induced in primary root apex and aerial parts of plants in response to NaCl. Additionally, GC-MS- and UPLC-based metabolite profiling revealed major changes in roots of <it>pop2-1 </it>mutant upon NaCl stress including accumulation of amino acids and decrease in carbohydrates content.</p> <p>Conclusions</p> <p>GABA metabolism was overall up-regulated in response to NaCl in <it>Arabidopsis</it>. Particularly, GABA-T was found to play a pivotal function and impairment of this step was responsible for a decrease in salt tolerance indicating that GABA catabolism was a determinant of <it>Arabidopsis </it>salt tolerance. GABA-T would act in salt responses in linking N and C metabolisms in roots.</p

: = Les Arnajons (Le-Puy-Sainte-Réparade, Bouches-du-Rhône): a new long chambered tomb of south-east France

International audienceA new dolmen was discovered in the Bouches-du-Rhône département during surveys and test trenches performed by Inrap prior to setting up a pipeline. The archaeological potential of the structure was only assessed and the project amendment allowed avoiding a complete excavation. The monument is located on a piedmont, in the Northern part of the Bouches-du-Rhône département, approximately 15 km North-northeast of Aix-en-Provence on the edge of the Durance valley. Embedded in a pit, the structure comprises three walls and the covering slab is missing. The test trenches show that the chamber contained at least two levels of deposits. The little series of furnishings are subjected to detailed studies, particularly with regard to the lithic industry (materials, technology, microwear analysis). The furniture and the radiocarbon dating corroborate the attribution of this monument to the Final Neolithic. The discussion pertains to integrating this dolmen into megalithism in the Provence region. It looks into the issues of chronology and cultural allocation. The potential links with other types of monuments, particularly with hypogeum such as Fontvieille's, remain an fundamental source of debate.Un nouveau dolmen a été découvert dans les Bouches-du-Rhône à l'occasion de prospections et sondages réalisés par l'Inrap. Le potentiel archéologique de la structure a seulement été évalué et la modification du projet d'aménagement a permis d'en éviter la fouille. Au nord du département des Bouches-du-Rhône, en bordure de la vallée de la Durance, le monument est localisé sur un piémont. Implantée en fosse, la structure de forme trapézoïdale orientée est-ouest est matérialisée par trois murs, la dalle de couverture a disparu. Les sondages montrent que la chambre contenait au moins deux niveaux de dépôts. La petite série de mobilier fait l'objet d'études détaillées, en particulier pour l'industrie lithique (matériaux, technologie, tracéologie). Le mobilier et la datation radiocarbone confirment que le monument a été utilisé pendant les premières phases du Néolithique final. La discussion porte sur l'intégration de ce dolmen au mégalithisme provençal. Elle examine les questions de chronologie et d'attribution culturelle. Les relations avec les autres types de monuments, en particulier avec les hypogées de type Fontvieille, restent une source essentielle de débat

Chemical Profile and Antimicrobial Activity of the Fungus-Growing Termite Strain Macrotermes Bellicosus Used in Traditional Medicine in the Republic of Benin

The fungus growing termite species Macrotermes bellicosus (M. bellicosus) is used in nutrition and traditional medicine in the Republic of Benin for the treatment of infectious and inflammatory diseases. Previous findings demonstrated evidence of anti-inflammatory and spasmolytic properties of M. bellicosus. The aim of the present study was to evaluate the antimicrobial potential of different extracts of M. bellicosus samples and determine the chemical profile of an ethanolic M. bellicosus extract. Chemical profiling was conducted using centrifugal partition chromatography and 13C-NMR, followed by MALDI-TOF MS. Major identified compounds include hydroquinone (HQ), methylhydroquinone (MHQ), 3,4-dihydroxyphenethyl glycol (DHPG), N-acetyldopamine (NADA) and niacinamide. The fatty acid mixture of the extract was mainly composed of linoleic and oleic acid and highlights the nutritional purpose of M. bellicosus. Using the Kirby–Bauer disc diffusion and broth microdilution assay, an antibacterial activity of M. bellicosus samples was observed against various clinical strains with a highest growth inhibition of S. aureus. In addition, HQ and MHQ as well as fractions containing DHPG, niacinamide and NADA inhibited S. aureus growth. The reported antimicrobial activity of M. bellicosus and identified active substances provide a rationale for the traditional medicinal use of M. bellicosus

Centrosomal Latency of Incoming Foamy Viruses in Resting Cells

Completion of early stages of retrovirus infection depends on the cell cycle. While gammaretroviruses require mitosis for proviral integration, lentiviruses are able to replicate in post-mitotic non-dividing cells. Resting cells such as naive resting T lymphocytes from peripheral blood cannot be productively infected by retroviruses, including lentiviruses, but the molecular basis of this restriction remains poorly understood. We demonstrate that in G0 resting cells (primary fibroblasts or peripheral T cells), incoming foamy retroviruses accumulate in close proximity to the centrosome, where they lie as structured and assembled capsids for several weeks. Under these settings, virus uncoating is impaired, but upon cell stimulation, Gag proteolysis and capsid disassembly occur, which allows viral infection to proceed. The data imply that foamy virus uncoating is the rate-limiting step for productive infection of primary G0 cells. Incoming foamy retroviruses can stably persist at the centrosome, awaiting cell stimulation to initiate capsid cleavage, nuclear import, and viral gene expression

Les Arnajons (Le-Puy-Sainte-Réparade, Bouches-du-Rhône) : un nouveau dolmen dans le Sud-Est de la France

Un nouveau dolmen a été découvert dans les Bouches-du-Rhône à l’occasion de prospections et sondages réalisés par l’Inrap. Le potentiel archéologique de la structure a seulement été évalué et la modification du projet d’aménagement a permis d’en éviter la fouille. Au nord du département des Bouches-du-Rhône, en bordure de la vallée de la Durance, le monument est localisé sur un piémont. Implantée en fosse, la structure de forme trapézoïdale orientée est-ouest est matérialisée par trois murs, la dalle de couverture a disparu. Les sondages montrent que la chambre contenait au moins deux niveaux de dépôts. La petite série de mobilier fait l’objet d’études détaillées, en particulier pour l’industrie lithique (matériaux, technologie, tracéologie). Le mobilier et la datation radiocarbone confirment que le monument a été utilisé pendant les premières phases du Néolithique final. La discussion porte sur l’intégration de ce dolmen au mégalithisme provençal. Elle examine les questions de chronologie et d’attribution culturelle. Les relations avec les autres types de monuments, en particulier avec les hypogées de type Fontvieille, restent une source essentielle de débat.A new dolmen was discovered in the Bouches-du-Rhône département during surveys and test trenches performed by Inrap prior to setting up a pipeline. The archaeological potential of the structure was only assessed and the project amendment allowed avoiding a complete excavation. The monument is located on a piedmont, in the Northern part of the Bouches-du-Rhône département, approximately 15 km North-northeast of Aix-en-Provence on the edge of the Durance valley. Embedded in a pit, the structure comprises three walls and the covering slab is missing. The test trenches show that the chamber contained at least two levels of deposits. The little series of furnishings are subjected to detailed studies, particularly with regard to the lithic industry (materials, technology, microwear analysis). The furniture and the radiocarbon dating corroborate the attribution of this monument to the Final Neolithic. The discussion pertains to integrating this dolmen into megalithism in the Provence region. It looks into the issues of chronology and cultural allocation. The potential links with other types of monuments, particularly with hypogeum such as Fontvieille’s, remain an fundamental source of debate

The three pillars of natural product dereplication. Alkaloids from the bulbs of Urceolina peruviana (C. Presl) J.F. Macbr. as a preliminary test case

open access articleThe role and importance of the identification of natural products are first discussed in the perspective of the study of secondary metabolites. The rapid identification of already reported compounds, or structural dereplication, is recognized as a key element in natural product chemistry. The biological taxonomy of metabolite producing organisms, the knowledge of metabolite molecular structures, and the availability of metabolite spectroscopic signatures are considered as the three pillars of structural dereplication. The role and the construction of databases is illustrated by references to the KNApSAcK, UNPD, CSEARCH, and COCONUT databases, and by the importance of calculated taxonomic and spectroscopic data as substitutes for missing or lost original ones. Two NMR-based tools, the PNMRP database that derives from UNPD, and KnapsackSearch, a database generator that provides taxonomically focused libraries of compounds, are proposed to the community of natural product chemists. The study of the alkaloids from Urceolina peruviana, a plant from the Andes used in traditional medicine for antibacterial and anticancer actions, has given the opportunity to test different approaches to dereplication, favoring the use of publicly available data sources