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Laboratoire Jacques-Louis Lions

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Université Paris Diderot, CNRS

Présentation

Le laboratoire, créé en 1969, porte le nom de son fondateur Jacques-Louis Lions. il s'agit maintenant d'une unité de recherche conjointe à l’Université Pierre et Marie Curie, à l’université Paris Diderot et au Centre National de la Recherche Scientifique.

Le Laboratoire Jacques-Louis Lions constitue le plus grand laboratoire de France et l'un des principaux au monde pour la formation et la recherche en mathématiques appliquées.

Il accueille l'activités de deux masters deuxième année ce qui représente un centaine d'étudiants. Ses activités recouvrent l’analyse, la modélisation et le calcul scientifique haute performance de phénomènes représentés par des équations aux dérivées partielles.

Fort d’environ 100 enseignants-chercheurs, chercheurs, ingénieurs, personnels administratifs permanents ou émérites, et d’autant de doctorants ou post-doctorants, il collabore avec le monde économique et avec d'autres domaines scientifiques à travers un large spectre d'applications : dynamique des fluides; physique, mécanique et chimie théoriques; contrôle, optimisation et finance; médecine et biologie; traitement du signal et des données.

Thèmes de recherche

Equations aux dérivées partielles et équations différentielles
Contrôle, optimisation, calcul des variations
Calcul scientifique, simulations numériques
Applications des mathématiques

[hal-01019615] Towards the modelling of conceptus morphogenesis in ruminants

Date: 5 aoû 2021 - 04:51

Desc: Our purpose is to understand the morphogenetic process at work in bovine conceptuses prior to implantation and develop a model that could resume and integrate the essential components of these mechanisms. We are particularly interested in the cellular interactions and physical constraints that could control the transition from the spherical blastocyst to the elongated conceptus.

[hal-02797585] Towards the modelling of conceptus morphogenesis in ruminants

Date: 5 aoû 2021 - 04:48

Desc: In ruminants, the elongation of the conceptus is marked by an anisotropic growth of the extra- embryonic tissues prior to implantation. This has not been related so far to processes such as cell deformation or specific cell organisation and could result from oriented cell divisions within the trophoblast [Wang, CRAS, 2009]. However, since the endoderm cells that underline the trophoblast display highly anisotropic features [Flechon, Genesis, 2007] it could be that this extra-embryonic layer drives the elongation process. To test these 2 hypotheses: oriented trophoblast division and endoderm driven process, we have started analysing these cells, their divisions and their interactions to extract biological and/or biophysical parameters. Once evaluated, we could integrate them and aim at the modelling of this ruminant specific morphogenesis.

[hal-01294630] Multiscale modeling of ovarian follicular development: From follicular morphogenesis to selection for ovulation

Date: 5 aoû 2021 - 04:47

Desc: In this review, we present multi-scale mathematical models of ovarian follicular development that are based on the embedding of physiological mechanisms into the cell scale. During basal follicular development, follicular growth operates through an increase in the oocyte size concomitant with the proliferation of its surrounding granulosa cells. We have developed a spatio-temporal model of follicular morphogenesis explaining how the interactions between the oocyte and granulosa cells need to be properly balanced to shape the follicle. During terminal follicular development, the ovulatory follicle is selected amongst a cohort of simultaneously growing follicles. To address this process of follicle selection, we have developed a model giving a continuous and deterministic description of follicle development, adapted to high numbers of cells and based on the dynamical and hormonally regulated repartition of granulosa cells into different cell states, namely proliferation, differentiation and apoptosis. This model takes into account the hormonal feedback loop involving the growing ovarian follicles and the pituitary gland, and enables the exploration of mechanisms regulating the number of ovulations at each ovarian cycle. Both models are useful for addressing ovarian physio-pathological situations. Moreover, they can be proposed as generic modelling environments to study various developmental processes and cell interaction mechanisms.