scispace - formally typeset
Search or ask a question
Institution

École normale supérieure de Cachan

EducationCachan, Île-de-France, France
About: École normale supérieure de Cachan is a education organization based out in Cachan, Île-de-France, France. It is known for research contribution in the topics: Decidability & Finite element method. The organization has 2717 authors who have published 5585 publications receiving 175925 citations.


Papers
More filters
Journal ArticleDOI
TL;DR: This work investigates the formation of a microbial community of the model organism Bacillus subtilis and writes a biomechanical model for the growth of the biofilm where the cell density is constant and the physical mechanism responsible for the spreading of the biomass is the pressure generated by the division of the bacteria.
Abstract: A general feature of mature biofilms is their highly heterogeneous architecture that partitions the microbial city into sectors with specific micro-environments. To understand how this heterogeneity arises, we have investigated the formation of a microbial community of the model organism Bacillus subtilis. We first show that the growth of macroscopic colonies is inhibited by the accumulation of ammoniacal by-products. By constraining biofilms to grow approximately as two-dimensional layers, we then find that the bacteria which differentiate to produce extracellular polymeric substances form tightly packed bacterial chains. In addition to the process of cellular chaining, the biomass stickiness also strongly hinders the reorganization of cells within the biofilm. Based on these observations, we then write a biomechanical model for the growth of the biofilm where the cell density is constant and the physical mechanism responsible for the spreading of the biomass is the pressure generated by the division of the bacteria. Besides reproducing the velocity field of the biomass across the biofilm, the model predicts that, although bacteria divide everywhere in the biofilm, fluctuations in the growth rates of the bacteria lead to a coarsening of the growing bacterial layer. This process of kinetic roughening ultimately leads to the formation of a rough biofilm surface exhibiting self-similar properties. Experimental measurements of the biofilm texture confirm these predictions.

60 citations

Journal ArticleDOI
TL;DR: The results demonstrate that soccer-training season was able to provide maturation free improvement in anthropometric and performance characteristics in young soccer players during the training season.
Abstract: The aim of this study was to evaluate the effect of a soccer-training season on the anthropometric and performance characteristics of elite youth soccer players. Two groups (age: 14.4 years) participated in this study: (1) 24 soccer players training 8 to 10 hours per week and (2) 26 non-athletic boys used as controls. Anthropometric measurements, aerobic (Yo-Yo Intermittent Recovery test level 1) and anaerobic (counter-movement-jump (CMJ), squat-jump (SqJ), five-jump-test (5JT), and speed (T5m, 10 m, 30 m)) performances were assessed twice during 8 months (T0: October; T1: May) of the competitive season. Data showed significant differences in height and weight at T0 between the two groups (P < 0.05), while no difference in the percentage of body fat (%BF) was observed. However, the soccer players were significantly taller and had lower %BF than age-matched controls at T1. Compared to the controls, the soccer players attained better results in the physical fitness test (P < 0.05) at T0 and T1 except in (T5m) sprinting speed. Hence, significant improvements (P < 0.05) in physical parameters were observed between T0 and T1 only in soccer players. The results demonstrate that soccer-training season was able to provide maturation free improvement in anthropometric and performance characteristics in young soccer players during the training season.

60 citations

Proceedings ArticleDOI
01 Jun 2019
TL;DR: In this paper, a fully blind video denoising method is proposed, which is achieved by fine-tuning a pre-trained AWGN network to the video with a novel frame-to-frame training strategy.
Abstract: Modeling the processing chain that has produced a video is a difficult reverse engineering task, even when the camera is available. This makes model based video processing a still more complex task. In this paper we propose a fully blind video denoising method, with two versions off-line and on-line. This is achieved by fine-tuning a pre-trained AWGN denoising network to the video with a novel frame-to-frame training strategy. Our denoiser can be used without knowledge of the origin of the video or burst and the post-processing steps applied from the camera sensor. The on-line process only requires a couple of frames before achieving visually pleasing results for a wide range of perturbations. It nonetheless reaches state-of-the-art performance for standard Gaussian noise, and can be used off-line with still better performance.

60 citations

Journal ArticleDOI
TL;DR: In this paper, the electrocatalytic process involves electropolymerized manganese porphyrin films as electrode materials in acetonitrile or dichloromethane solution containing 1-methylimidazole and benzoic (or acetic) anhydride, with acceptable catalytic efficiency (up to 500 turnovers of the catalyst per hour) and faradaic yield.
Abstract: Some recently published results on the electrocatalytic oxidation of hydrocarbons, olefins and a thioacetamide derivative by molecular oxygen are described. The catalytic process involves electropolymerized manganese porphyrin films as electrode materials in acetonitrile or dichloromethane solution containing 1-methylimidazole and benzoic (or acetic) anhydride, with acceptable catalytic efficiency (up to 500 turnovers of the catalyst per hour) and faradaic yield (up to 98%). Confinement of the catalyst on the electrode surface markedly improves its stability compared with that of homogeneous electrocatalytic systems and makes the supported porphyrin stable and reusable.

60 citations

Journal ArticleDOI
TL;DR: In this article, an optoelectronic oscillator can be used for measuring refractive index by detecting the change of the oscillation frequency, which can decrease to 10-3 or less if the mechanic vibrations, the temperature control of liquid, and the long-term stability of oscillator are improved.
Abstract: The purpose of this letter is to present a preliminary experiment, showing that an optoelectronic oscillator can be used for measuring refractive index by detecting the change of the oscillation frequency. The uncertainty of the measurement is of about 10-2. However, this value can decrease to 10-3 or less if the mechanic vibrations, the temperature control of liquid, and the long-term stability of the oscillator are improved. Measurements have been performed for acetonitrile, acetone, dioxane, and chloroform at the wavelength of 1535 nm and at 25°C approximately.

60 citations


Authors

Showing all 2722 results

NameH-indexPapersCitations
Shi Xue Dou122202874031
Olivier Hermine111102643779
John R. Reynolds10560750027
Shaul Mukamel95103040478
Tomás Torres8862528223
Ifor D. W. Samuel7460523151
Serge Abiteboul7327824576
Stéphane Roux6862719123
Zeger Debyser6740416531
Louis Nadjo6426412596
Praveen K. Thallapally6419012110
Andrew Travers6319313537
Shoji Takeuchi6369214704
Bineta Keita6327412053
Yves Mély6236813478
Network Information
Related Institutions (5)
École Polytechnique Fédérale de Lausanne
98.2K papers, 4.3M citations

92% related

École Normale Supérieure
99.4K papers, 3M citations

91% related

Georgia Institute of Technology
119K papers, 4.6M citations

91% related

University of Paris-Sud
52.7K papers, 2.1M citations

90% related

University of Paris
174.1K papers, 5M citations

90% related

Performance
Metrics
No. of papers from the Institution in previous years
YearPapers
20233
202222
202121
202029
201958
201879