Should Metabolic Diseases Be Systematically Screened in Nonsyndromic Autism Spectrum Disorders?

Abstract Background: In the investigation of autism spectrum disorders (ASD), a genetic cause is found in approximately 10-20%. Among these cases, the prevalence of the rare inherited metabolic disorders (IMD) is unknown and poorly evaluated. An IMD responsible for ASD is usually identified by the associated clinical phenotype such as dysmorphic features, ataxia, microcephaly, epilepsy, and severe intellectual disability (ID). In rare cases, however, ASD may be considered as nonsyndromic at the onset of a related IMD

Modélisation discrète de la résistance à la traction d'une couche d'argile

National audienceLa méthode des éléments discrets est utilisée pour simuler la résistance à la traction et l'endommagement d'une couche d'argile soumise à des sollicitations de flexion. C'est notamment le cas des barrières argileuses passives des centres de stockage de déchets. Comme le sol étudié est plastique, la méthode des éléments discrets a d'abord été calibrée sur des résultats préliminaires qui prennent en compte les propriétés cohésives du matériau. Différentes lois de contact et d'interaction ont été testées et montrent que la modélisation est capable de reproduire les mécanismes d'endommagement observés. Ces résultats numériques prometteurs ont été étendus à la simulation d'une barrière étanche d'un centre de stockage de déchets et comparés à des résultats expérimentaux en vraie grandeur réalisés sur une installation de stockage de déchets

Modélisation discrète de la résistance à la traction d'une couche d'argile

National audienceLa méthode des éléments discrets est utilisée pour simuler la résistance à la traction et l'endommagement d'une couche d'argile soumise à des sollicitations de flexion. C'est notamment le cas des barrières argileuses passives des centres de stockage de déchets. Comme le sol étudié est plastique, la méthode des éléments discrets a d'abord été calibrée sur des résultats préliminaires qui prennent en compte les propriétés cohésives du matériau. Différentes lois de contact et d'interaction ont été testées et montrent que la modélisation est capable de reproduire les mécanismes d'endommagement observés. Ces résultats numériques prometteurs ont été étendus à la simulation d'une barrière étanche d'un centre de stockage de déchets et comparés à des résultats expérimentaux en vraie grandeur réalisés sur une installation de stockage de déchets

Anisotropic Fibrous Scaffolds for Articular Cartilage Regeneration

Articular cartilage lesions, which can progress to osteoarthritis, are a particular challenge for regenerative medicine strategies, as cartilage function stems from its complex depth-dependent microstructural organization, mechanical properties, and biochemical composition. Fibrous scaffolds offer a template for cartilage extracellular matrix production; however, the success of homogeneous scaffolds is limited by their inability to mimic the cartilage's zone-specific organization and properties. We fabricated trilaminar scaffolds by sequential electrospinning and varying fiber size and orientation in a continuous construct, to create scaffolds that mimicked the structural organization and mechanical properties of cartilage's collagen fibrillar network. Trilaminar composite scaffolds were then compared to homogeneous aligned or randomly oriented fiber scaffolds to assess in vitro cartilage formation. Bovine chondrocytes proliferated and produced a type II collagen and a sulfated glycosaminoglycan-rich extracellular matrix on all scaffolds. Furthermore, all scaffolds promoted significant upregulation of aggrecan and type II collagen gene expression while downregulating that of type I collagen. Compressive testing at physiological strain levels further demonstrated that the mechanical properties of trilaminar composite scaffolds approached those of native cartilage. Our results demonstrate that trilaminar composite scaffolds mimic key organizational characteristics of native cartilage, support in vitro cartilage formation, and have superior mechanical properties to homogenous scaffolds. We propose that these scaffolds offer promise in regenerative medicine strategies to repair articular cartilage lesions

A novel role for the root cap in phosphate uptake and homeostasis

Abstract The root cap has a fundamental role in sensing environmental cues as well as regulating root growth via altered meristem activity. Despite this well-established role in the control of developmental processes in roots, the root cap's function in nutrition remains obscure. Here, we uncover its role in phosphate nutrition by targeted cellular inactivation or phosphate transport complementation in Arabidopsis, using a transactivation strategy with an innovative highresolution real-time 33 P imaging technique. Remarkably, the diminutive size of the root cap cells at the root-to-soil exchange surface accounts for a significant amount of the total seedling phosphate uptake (approximately 20%). This level of Pi absorption is sufficient for shoot biomass production (up to a 180% gain in soil), as well as repression of Pi starvation-induced genes. These results extend our understanding of this important tissue from its previously described roles in environmental perception to novel functions in mineral nutrition and homeostasis control

A novel role for the root cap in phosphate uptake and homeostasis

Abstract The root cap has a fundamental role in sensing environmental cues as well as regulating root growth via altered meristem activity. Despite this well-established role in the control of developmental processes in roots, the root cap's function in nutrition remains obscure. Here, we uncover its role in phosphate nutrition by targeted cellular inactivation or phosphate transport complementation in Arabidopsis, using a transactivation strategy with an innovative highresolution real-time 33 P imaging technique. Remarkably, the diminutive size of the root cap cells at the root-to-soil exchange surface accounts for a significant amount of the total seedling phosphate uptake (approximately 20%). This level of Pi absorption is sufficient for shoot biomass production (up to a 180% gain in soil), as well as repression of Pi starvation-induced genes. These results extend our understanding of this important tissue from its previously described roles in environmental perception to novel functions in mineral nutrition and homeostasis control

Construction of Chromosome Segment Substitution Lines in Peanut (Arachis hypogaea L.) Using a Wild Synthetic and QTL Mapping for Plant Morphology

Abstract Chromosome segment substitution lines (CSSLs) are powerful QTL mapping populations that have been used to elucidate the molecular basis of interesting traits of wild species. Cultivated peanut is an allotetraploid with limited genetic diversity. Capturing the genetic diversity from peanut wild relatives is an important objective in many peanut breeding programs. In this study, we used a marker-assisted backcrossing strategy to produce a population of 122 CSSLs from the cross between the wild synthetic allotetraploid (A. ipaënsis6A. duranensis) 4x and the cultivated Fleur11 variety. The 122 CSSLs offered a broad coverage of the peanut genome, with target wild chromosome segments averaging 39.2 cM in length. As a demonstration of the utility of these lines, four traits were evaluated in a subset of 80 CSSLs. A total of 28 lines showed significant differences from Fleur11. The line6trait significant associations were assigned to 42 QTLs: 14 for plant growth habit, 15 for height of the main stem, 12 for plant spread and one for flower color. Among the 42 QTLs, 37 were assigned to genomic regions and three QTL positions were considered putative. One important finding arising from this QTL analysis is that peanut growth habit is a complex trait that is governed by several QTLs with different effects. The CSSL population developed in this study has proved efficient for deciphering the molecular basis of trait variations and will be useful to the peanut scientific community for future QTL mapping studies