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Physique Théorique
(61) Production(s) de l'année 2021
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Macrophage morphological plasticity and migration is Rac signalling and MMP9 dependant
Auteur(s): Travnickova Jana, Nhim Sandra, Abdellaoui Naoill, Djouad Farida, Nguyen-Chi Mai, Parmeggiani A., Kissa Karima
(Article) Publié:
Scientific Reports, vol. 11 p.10123 (2021)
Texte intégral en Openaccess :
Ref HAL: hal-03323838_v1
PMID 33980872
DOI: 10.1038/s41598-021-88961-7
WoS: WOS:000652603700003
Exporter : BibTex | endNote
Résumé: In vitro, depending on extracellular matrix (ECM) architecture, macrophages migrate either in amoeboid or mesenchymal mode; while the first is a general trait of leukocytes, the latter is associated with tissue remodelling via Matrix Metalloproteinases (MMPs). To assess whether these stereotyped migrations could be also observed in a physiological context, we used the zebrafish embryo and monitored macrophage morphology, behaviour and capacity to mobilise haematopoietic stem/progenitor cells (HSPCs), as a final functional readout. Morphometric analysis identified 4 different cell shapes. Live imaging revealed that macrophages successively adopt all four shapes as they migrate through ECM. Treatment with inhibitors of MMPs or Rac GTPase to abolish mesenchymal migration, suppresses both ECM degradation and HSPC mobilisation while differently affecting macrophage behaviour. This study depicts real time macrophage behaviour in a physiological context and reveals extreme reactivity of these cells constantly adapting and switching migratory shapes to achieve HSPCs proper mobilisation.
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New interaction potentials for alkaline earth silicate and borate glasses
Auteur(s): Shih Yueh-Ting, Sundararaman Siddharth, Ispas S., Huang Liping
(Article) Publié:
Journal Of Non-Crystalline Solids, vol. 565 p.120853 (2021)
Texte intégral en Openaccess :
Ref HAL: hal-03323812_v1
DOI: 10.1016/j.jnoncrysol.2021.120853
WoS: WOS:000663076400005
Exporter : BibTex | endNote
Résumé: New interaction potentials were developed for molecular dynamics simulations to study the role of Mg and Ca in modifying the structure and properties of alkaline earth silicates and borates. Competition between the depolymerization of the silica network and the formation of new bonds between oxygen atoms and modifiers leads to the enhancement of the elastic moduli with increasing modifier content in alkaline earth silicate glasses. Compared with calcium silicate, the higher elastic moduli of magnesium silicate result from a higher connectivity of the overall glass network due to the incorporation of fourfold coordinated magnesium and a more rigid connection between oxygen atoms and modifiers. In contrast to the silicates, the effect of modifier on the elastic moduli of alkaline earth borates is dominated by the formation of fourfold coordinated boron (N4). Calcium borate with higher N4 shows a more rigid network structure and higher elastic moduli.
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Renormalization group optimized $\lambda \phi^4$ pressure at next-to-next-to-leading order
Auteur(s): Fernandez L., Kneur J.-L.
(Article) Publié:
-Phys.rev.d, vol. 104 p.096012 (2021)
Texte intégral en Openaccess :
Ref HAL: hal-03319381_v1
Ref Arxiv: 2107.13328
Ref INSPIRE: 1894553
DOI: 10.1103/PhysRevD.104.096012
Ref. & Cit.: NASA ADS
Exporter : BibTex | endNote
Résumé: We investigate the renormalization group optimized perturbation theory (RGOPT) at the next-to-next-to-leading order (NNLO) for the thermal scalar field theory. From comparing three thus available successive RGOPT orders, we illustrate the efficient resummation and very good apparent convergence properties of the method. In particular, the remnant renormalization scale dependence of thermodynamical quantities is drastically improved as compared to both standard perturbative expansions and other related resummation methods, such as the screened perturbation theory. Our present results thus constitute a useful first NNLO illustration in view of NNLO applications of this approach to the more involved thermal QCD.
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D-instantons in Type IIA string theory on Calabi-Yau threefolds
Auteur(s): Alexandrov S., Sen Ashoke, Stefański Bogdan
(Article) Publié:
Journal Of High Energy Physics, vol. 2021 p.18 (2021)
Texte intégral en Openaccess :
Ref HAL: hal-03319142_v1
Ref Arxiv: 2108.04265
DOI: 10.1007/JHEP11(2021)018
Ref. & Cit.: NASA ADS
Exporter : BibTex | endNote
Résumé: Type IIA string theory compactified on a Calabi-Yau threefold has a hypermultiplet moduli space whose metric is known to receive non-perturbative corrections from Euclidean D2-branes wrapped on 3-cycles. These corrections have been computed earlier by making use of mirror symmetry, S-duality and twistorial description of quaternionic geometries. In this paper we compute the leading corrections in each homology class using a direct world-sheet approach without relying on any duality symmetry or supersymmetry. Our results are in perfect agreement with the earlier predictions.
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Experimental Test of the Edwards Volume Ensemble of Tapped Granular Packings
Auteur(s): Yuan Ye, Xing Yi, Zheng Jie, Li Zhifeng, Yuan Houfei, Zhang Shuyang, Zeng Zhikun, Xia Chengjie, Tong Hua, Kob W., Zhang Jie, Wang Yujie
(Article) Publié:
Physical Review Letters, vol. 127 p.018002 (2021)
Texte intégral en Openaccess :
Ref HAL: hal-03287898_v1
PMID 34270306
DOI: 10.1103/PhysRevLett.127.018002
Exporter : BibTex | endNote
Résumé: Using x-ray tomography, we experimentally investigate granular packings subject to mechanical tapping for three types of beads with different friction coefficients. We validate the Edwards volume ensemble in these three-dimensional granular systems and establish a granular version of thermodynamic zeroth law. Within the Edwards framework, we also explicitly clarify how friction influences granular statistical mechanics by modifying the density of states, which allows us to determine the entropy as a function of packing fraction and friction. Additionally, we obtain a granular jamming phase diagram based on geometric coordination number and packing fraction.
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Perturbatively conserved higher nonlocal integral invariants of free-surface deep-water gravity waves
Auteur(s): Neveu A.
(Article) Publié:
Physics Of Fluids, vol. 33 p.032105 (2021)
Texte intégral en Openaccess :
Ref HAL: hal-03252526_v1
DOI: 10.1063/5.0039868
WoS: 000630507900001
Exporter : BibTex | endNote
Résumé: We exhibit a set of six explicit higher nonlocal integral invariants of free-surface deep-water gravity waves conservedin lowest nontrivial orders of perturbation in the amplitude of the surface displacement.
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