Variational solution of the Gross-Neveu model at finite temperature in the large N limit

We use a nonperturbative variational method to investigate the phase transition of the Gross-Neveu model. It is shown that the variational procedure can be generalized to the finite temperature case. The large N result for the phase transition is correctly reproduced.Comment: 12 p., 1 fig, this is the version which will appear in the Phys Lett B, it differs from the previous one in what concerns the introduction and conclusions (re written), several references have been adde

Looping and clustering model for the organization of protein-DNA complexes on the bacterial genome

The bacterial genome is organized by a variety of associated proteins inside a structure called the nucleoid. These proteins can form complexes on DNA that play a central role in various biological processes, including chromosome segregation. A prominent example is the large ParB-DNA complex, which forms an essential component of the segregation machinery in many bacteria. ChIP-Seq experiments show that ParB proteins localize around centromere-like parS sites on the DNA to which ParB binds specifically, and spreads from there over large sections of the chromosome. Recent theoretical and experimental studies suggest that DNA-bound ParB proteins can interact with each other to condense into a coherent 3D complex on the DNA. However, the structural organization of this protein-DNA complex remains unclear, and a predictive quantitative theory for the distribution of ParB proteins on DNA is lacking. Here, we propose the looping and clustering model, which employs a statistical physics approach to describe protein-DNA complexes. The looping and clustering model accounts for the extrusion of DNA loops from a cluster of interacting DNA-bound proteins that is organized around a single high-affinity binding site. Conceptually, the structure of the protein-DNA complex is determined by a competition between attractive protein interactions and loop closure entropy of this protein-DNA cluster on the one hand, and the positional entropy for placing loops within the cluster on the other. Indeed, we show that the protein interaction strength determines the 'tightness' of the loopy protein-DNA complex. Thus, our model provides a theoretical framework for quantitatively computing the binding profiles of ParB-like proteins around a cognate (parS) binding site

Methodes d'analyse fonctionnelle pour la prolongation analytique de resultats perturbatifs en chromodynamique quantique

SIGLECNRS T Bordereau / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

Color measurements of turbid liquids (European Patent)

Une méthode permettant la mesure spectrocolorimétrique des solutions opaques très diffusantes, de type jus de fruits, dans leur packaging d'origine. Les appareils courants sur le marché (spectrocolorimètres) ne permettent pas de réaliser cette mesure. La méthode s'affranchit des contraintes présentes dans ces appareils

Color measurements of turbid liquids (European Patent)

Une méthode permettant la mesure spectrocolorimétrique des solutions opaques très diffusantes, de type jus de fruits, dans leur packaging d'origine. Les appareils courants sur le marché (spectrocolorimètres) ne permettent pas de réaliser cette mesure. La méthode s'affranchit des contraintes présentes dans ces appareils

Modelling DNA segregation and positioning in the bacterial genome

Compréhension et analyse des systèmes complexes par Agropolis InternationalActivities around modelling DNA segregation and positioning in the bacterial genom

Modélisation de la ségrégation et du positionnementdu génome bactérien

Compréhension et analyse des systèmes complexes par Agropolis InternationalResumé des activités de l'equipe SCPN sur la modélisation de la ségrégation et du positionnement du génome bactéri

Modélisation de la ségrégation et du positionnementdu génome bactérien

Compréhension et analyse des systèmes complexes par Agropolis InternationalResumé des activités de l'equipe SCPN sur la modélisation de la ségrégation et du positionnement du génome bactéri

Physico-mathematical modelling of intracellular molecular transport

Compréhension et analyse des systèmes complexes par Agropolis InternationalABout our activities on physico-mathematical modelling of intracellularmolecular transpor

Modélisation physico-mathématique du transport moléculaire intracellulaire

Compréhension et analyse des systèmes complexes par Agropolis InternationalCompte rendu des activités autour de la modélisation physico-mathématique du transport moléculaire intracellulair