Search results for "G22"
showing 10 items of 10 documents
An ancestral allele of grapevine transcription factor MYB14 promotes plant defence
2016
Highlight The molecular mechanisms underlying the elevated inducibility of stilbene in pathogen-resistant Vitis sylvestris can be explained by the increased inducibility of the MYB14 promoter.
The grapevine flagellin receptor VvFLS2 differentially recognizes flagellin-derived epitopes from the endophytic growth-promoting bacterium Burkholde…
2014
International audience; The role of flagellin perception in the context of plant beneficial bacteria still remains unclear. Here, we characterized the flagellin sensing system flg22-FLAGELLIN SENSING 2 (FLS2) in grapevine, and analyzed the flagellin perception in the interaction with the endophytic plant growth-promoting rhizobacterium (PGPR) Burkholderia phytofirmans. The functionality of the grapevine FLS2 receptor, VvFLS2, was demonstrated by complementation assays in the Arabidopsis thaliana fls2 mutant, which restored flg22-induced H2O2 production and growth inhibition. Using synthetic flg22 peptides from different bacterial origins, we compared recognition specificities between VvFLS2…
Testing For Asymmetric Information In Insurance Markets With Unobservable Types
2008
In two important recent papers, Finkelstein and McGarry [25] and Finkelstein and Poterba [28] propose a new test for asymmetric information in insurance markets that considers explicitly unobserved heterogeneity in insurance demand. In this paper we propose an alternative implementation of the Finkelstein-McGarry-Poterba test based on the identification of unobservable types by use of finite mixture models. The actual implementation of our test follows some recent advances on marginal modelling as applied to latent class analysis; formal testing procedures for the null of asymmetric information and for the hypothesis that private information is indeed multidimensional can be performed by im…
Catastrophic risks and the pricing of catastrophe equity put options
2021
In this paper, after a review of the most common financial strategies and products that insurance companies use to hedge catastrophic risks, we study an option pricing model based on processes with jumps where the catastrophic event is captured by a compound Poisson process with negative jumps. Given the importance that catastrophe equity put options (CatEPuts) have in this context, we introduce a pricing approach that provides not only a theoretical contribution whose applicability remains confined to purely numerical examples and experiments, but which can be implemented starting from real data and applied to the evaluation of real CatEPuts. We propose a calibration framework based on his…
Dans quelle mesure les préférences individuelles contraignent-elles le développement du marché de l'assurance dépendance ?
2015
Dans un contexte de vieillissement de la population, différents scenarii sont envisagés pour réformer l’organisation et le financement de la prise en charge des personnes âgées dépendantes. La place de la prévoyance individuelle dans le financement de la dépendance est à ce titre largement débattue. À l’heure actuelle, malgré des restes à charge potentiellement conséquents, peu d’individus disposent d’une couverture assurantielle. Cet article vise à enrichir la littérature existante en évaluant dans quelle mesure les préférences observées dans la population limitent cette couverture. Nous mobilisons pour cela l’enquête Patrimoine et préférences vis-à-vis du temps et du risque (Pater) de 201…
Rough linear PDE's with discontinuous coefficients - existence of solutions via regularization by fractional Brownian motion
2020
We consider two related linear PDE's perturbed by a fractional Brownian motion. We allow the drift to be discontinuous, in which case the corresponding deterministic equation is ill-posed. However, the noise will be shown to have a regularizing effect on the equations in the sense that we can prove existence of solutions for almost all paths of the fractional Brownian motion.
Random time-changes and asymptotic results for a class of continuous-time Markov chains on integers with alternating rates
2021
We consider continuous-time Markov chains on integers which allow transitions to adjacent states only, with alternating rates. We give explicit formulas for probability generating functions, and also for means, variances and state probabilities of the random variables of the process. Moreover we study independent random time-changes with the inverse of the stable subordinator, the stable subordinator and the tempered stable subodinator. We also present some asymptotic results in the fashion of large deviations. These results give some generalizations of those presented in Di Crescenzo A., Macci C., Martinucci B. (2014).
Identification et caractérisation du récepteur à la flagelline (VvFLS2) et recherche du récepteur aux chito-oligosaccharides chez la vigne
2014
Pattern-recognition receptors (PRRs) play a key role in plant immunity by assuring recognition of microbe-associated molecular patterns (MAMPs), signature of microbial presence. MAMP perception constitutes the first layer of pathogen detection and activates defense mechanisms that aim to block the intruder. This study brings an insight into how grapevine (Vitis vinifera) perceives two MAMPs: the flagellin-derived flg22 peptide and chitin, which are conserved motifs occurring over the whole bacterial and fungal classes, respectively. This study analyzed MAMP-triggered early signaling events, defense gene expression and also the efficiency of elicited defense against gray mold and downy milde…
Identification of the VvFLS2 grapevine flagellin receptor by a functional genomics strategy
2013
National audience; Grapevine (Vitis vinifera) is a crop of high agronomic interest subject to many destructive diseases. Pattern recognition receptors (PRRs) mediate detection of potential pathogens via the perception of pathogen associated molecular patterns (PAMPs), which is important for plant disease resistance. A well studied PRR is the Arabidopsis leucine-rich repeat receptor kinase FLS2 that recognizes bacterial flagellin (or its minimal motif flg22). Flagellin perception plays an important role in restricting bacterial invasion into plant leaves. Until now, functional FLS2 orthologues have been characterized in Nicotiana benthamiana, rice and tomato. Despite its economical importanc…
Perception of pathogenic or beneficial bacteria and their evasion of host immunity: pattern recognition receptors in the frontline
2015
International audience; Plants are continuously monitoring the presence of microorganisms to establish an adapted response. Plants commonly use pattern recognition receptors (PRRs) to perceive microbe- or pathogen-associated molecular patterns (MAMPs/PAMPs) which are microorganism molecular signatures. Located at the plant plasma membrane, the PRRs are generally receptor-like kinases (RLKs) or receptor-like proteins (RLPs). MAMP detection will lead to the establishment of a plant defense program called MAMP-triggered immunity (MTI). In this review, we overview the RLKs and RLPs that assure early recognition and control of pathogenic or beneficial bacteria. We also highlight the crucial func…