Surgical Application of Human Amniotic Membrane and Amnion-Chorion Membrane in the Oral Cavity and Efficacy Evaluation: Corollary With Ophthalmological and Wound Healing Experiences

Due to its intrinsic properties, there has been growing interest in human amniotic membrane (hAM) in recent years particularly for the treatment of ocular surface disorders and for wound healing. Herein, we investigate the potential use of hAM and amnion-chorion membrane (ACM) in oral surgery. Based on our analysis of the literature, it appears that their applications are very poorly defined. There are two options: implantation or use as a cover material graft. The oral cavity is submitted to various mechanical and biological stimulations that impair membrane stability and maintenance. Thus, some devices have been combined with the graft to secure its positioning and protect it in this location. This current opinion paper addresses in detail suitable procedures for hAM and ACM utilization in soft and hard tissue reconstruction in the oral cavity. We address their implantation and/or use as a covering, storage format, application side, size and number, multilayer use or folding, suture or use of additional protective covers, re-application and resorption/fate. We gathered evidence on pre- and post-surgical care and evaluation tools. Finally, we integrated ophthalmological and wound healing practices into the collected information. This review aims to help practitioners and researchers better understand the application of hAM and ACM in the oral cavity, a place less easily accessible than ocular or cutaneous surfaces. Additionally, it could be a useful reference in the generation of new ideas for the development of innovative protective covering, suturing or handling devices in this specific indication. Finally, this overview could be considered as a position paper to guide investigators to fulfill all the identified criteria in the future

Brownian motion with radioactive decay to calculate the dynamic bulk modulus of gases saturating porous media according to Biot theory

We present a new stochastic simulation method for determining the long-wavelength effective dynamic bulk modulus of gases, such as ambient air, saturating porous media with relatively arbitrary microgeometries, i.e., simple enough to warrant Biot’s simplification that the fluid and solid motions are quasi-incompressible motions at the pore scale. The simulation method is based on the mathematical isomorphism between two different physical problems. One of them is the actual Fourier heat exchange problem between gas and solid in the context of Biot theory. The other is a diffusion-disintegration-controlled problem that considers Brownian motion of diffusing particles undergoing radioactive-type decay in the pore volume and instant decay at the pore walls. By appropriately choosing the decay time and the diffusion coefficient, the stochastic algorithm we develop to determine the average lifetime of the diffusing particles, directly gives the effective apparent modulus of the saturating fluid. We show how it leads to purely geometric stochastic constructions to determine a number of geometrical parameters. After validating the algorithm for cylindrical circular pores, its power is illustrated for the case of fibrous materials of the type used in noise control. The results agree well with a model of the effective modulus with three purely geometric parameters of the pore space: static thermal permeability divided by porosity, static thermal tortuosity, and thermal characteristic length

Defining QTL Boundaries from GWAS Results

International audienceAlthough it is necessary to identify candidate genes, there is actually no well spread method to define QTL boundaries from genome wide association studies (GWAS). Indeed, GWAS results are mostly shown using simple Manhattan plots because in an association panel the link between linkage disequilibrium (LD) and genetic or physical distances is much more complex than in a biparental population. Thus, authors fixed a more or less arbitrary window around associated markers, often based on mean LD decay. But massive variation of LD exists along the chromosomes. Moreover, authors control the error Type I (false positive) using a p-value threshold or through method based on p-value distribution to define significant marker-trait association. But the way QTL boundaries are designed can also lead to false positive. Thus, the real error Type I is composed of two errors, (1) a QTL is defined although the initial marker-trait association is not real, (2) the marker trait association is real but the QTL boundaries do not contain the causal mutation. We used genotyping data (~24,000 SNP) from a 214-variety elite wheat panel defined for association mapping. We assessed by simulation the power of detection and false discovery rate of several QTL construction methods depending on traits heritabilities, locus explained variance, and p-value threshold. Results revealed that real error Type I is much higher than expected and mainly controlled by the ability to well-define QTL boundaries. Methods are discussed regarding QTL coverage, real error Type I, and power of detection balanced altogether

A genome-wide identification of chromosomal regions determining nitrogen use efficiency components in wheat (Triticum aestivum L.)

Improving nitrogen use efficiency is a key factor to sustainably ensure global production increase. However, while high-throughput screening methods remain at a developmental stage, genetic progress may be mainly driven by marker-assisted selection. The objective of this study was to identify chromosomal regions associated with nitrogen use efficiency-related traits in bread wheat (Triticum aestivum L.) using a genome-wide association approach. Two hundred and fourteen European elite varieties were characterised for 28 traits related to nitrogen use efficiency in eight environments in which two different nitrogen fertilisation levels were tested. The genome-wide association study was carried out using 23,603 SNP with a mixed model for taking into account parentage relationships among varieties. We identified 1,010 significantly associated SNP which defined 333 chromosomal regions associated with at least one trait and found colocalisations for 39 % of these chromosomal regions. A method based on linkage disequilibrium to define the associated region was suggested and discussed with reference to false positive rate. Through a network approach, colocalisations were analysed and highlighted the impact of genomic regions controlling nitrogen status at flowering, precocity, and nitrogen utilisation on global agronomic performance. We were able to explain 40 ± 10 % of the total genetic variation. Numerous colocalisations with previously published genomic regions were observed with such candidate genes as Ppd-D1, Rht-D1, NADH-Gogat, and GSe. We highlighted selection pressure on yield and nitrogen utilisation discussing allele frequencies in associated regions. (Résumé d'auteur

Improvement of the grain filling of wheat through the modulation of NADH-glutamate synthase activity

The invention relates to a method for increasing the grain filling of a plant, wherein said method comprises overexpressing in said plant a wheat NADH-dependent glutamate synthase, in order to increase the grain weight and/or the grain protein content.L'invention concerne un procédé pour augmenter le remplissage du grain d'une plante, ledit procédé comprenant la surexpression dans ladite plante d'une glutamate synthase NADH-dépendante de blé, afin d'augmenter le poids du grain et/ou la teneur en protéine du grain

Identification of QTLs affecting post-anthesis heat stress responses in European bread wheat

International audienceHeat stress is a critical abiotic stress for winter bread wheat ( Triticum aestivum L.) especially at the flowering and grain filling stages, limiting its growth and productivity in Europe and elsewhere. The breeding of new high-yield and stress-tolerant wheat varieties requires improved understanding of the physiological and genetic bases of heat tolerance. To identify genomic areas associated with plant and grain characteristics under heat stress, a panel of elite European wheat varieties ( N = 199) was evaluated under controlled conditions in 2016 and 2017. A split-plot design was used to test the effects of high temperature for ten days after flowering. Flowering time, leaf chlorophyll content, the number of productive spikes, grain number, grain weight and grain size were measured, and the senescence process was modeled. Using genotyping data from a 280 K SNP chip, a genome-wide association study was carried out to test the main effect of each SNP and the effect of SNP × treatment interaction. Genotype × treatment interactions were mainly observed for grain traits measured on the main shoots and tillers. We identified 10 QTLs associated with the main effect of at least one trait and seven QTLs associated with the response to post-anthesis heat stress. Of these, two main QTLs associated with the heat tolerance of thousand-kernel weight were identified on chromosomes 4B and 6B. These QTLs will be useful for breeders to improve grain yield in environments where terminal heat stress is likely to occur

Genome-wide identification of chromosomal regions determining nitrogen use efficiency components in wheat

International audienc

Selection and characterization of a winter wheat diversity panel

Selection and characterization of a winter wheat diversity panel. 7. Congress and Associate Symposiums of Breads of the future: genomics, genetics, breedin

Phenotypic characterization of French elite germplasm in response to drought stress

International audienc