Search results for "polarization."

Electrohydrodynamic instabilities and orientation of dielectric ellipsoids in low-conducting fluids.

2000

We study the dynamics of an ellipsoidal particle in a weakly conducting dielectric liquid when submitted to a dc electric field. At low field intensities, the particle long axis is aligned in the field direction. When the field strength is increased, we show that, depending on the initial orientation of the particle, there exist two stable orientations: the one with the long axis parallel to the field direction remains possible while a spinning state with the long axis perpendicular to the field appears. This last striking orientation is due to the finite Maxwell-Wagner polarization relaxation time. For sufficiently high field intensities, each state loses its stability and the particle dyn…

Cellular Mechanisms of Subplate-Driven and Cholinergic Input-Dependent Network Activity in the Neonatal Rat Somatosensory Cortex

2008

Early coordinated network activity promotes the development of cortical structures. Although these early activity patterns have been recently characterized with respect to their developmental, spatial and dynamic properties, the cellular mechanisms by which specific neuronal populations trigger coordinated activity in the neonatal cerebral cortex are still poorly understood. Here we characterize the cellular and molecular processes leading to generation of network activity during early postnatal development. We show that the somatosensory cortex of newborn rats expresses cholinergic-driven calcium transients which are synchronized within the deeply located subplate. Correspondingly, endogen…

Conduction band polarization in some CMR materials

2000

First principles electronic structure calculations reveal certain important common features in the conduction band polarization of many of the newly examined colossal magnetoresistance (CMR) materials. Most CMR compounds seem to possess a localized, magnetic band slightly below the Fermi energy. This localized band transfers polarization to a relatively broad conduction band. The nature of the two bands in different systems can be quite distinct. In the perovskite-derived manganese oxides, the magnetic band is derived from $Mn t_{2g}$ states while the conduction band is derived from Mn e states. In the chalcospinel $Fe_{^0.^5}$ $Cu_{^0.^5}$ $Cr_{2}$$ S_{4}$ , the $Crt_{2g}$ states which are…

Mucosal immunology and probiotics.

2013

The cross-talk between the mucosa-associated immune system and microbiota is critical in mucosal tissue homeostasis as well as in protection against infectious and inflammatory diseases occurring at mucosal sites. This recent evidence has paved the way to therapeutic approaches aimed at modulating the mucosa-associated immune system using probiotics. Different strains of probiotics possess the ability to finely regulate dendritic cell (DC) activation, polarizing the subsequent T cell activity toward Th1 (e.g. Lactobacillus (Lb) acidophilus), Th2 (Lb.reuteri and Bifidobacterium bifidum) or, as more recently demonstrated, Th17 responses induced by specific strains such as Lb.rhamnosus GG and …

The Politicization of European Union Trade Policy: Radical-Left Euroskeptic Opposition to the Transatlantic Trade and Investment Partnership

2021

This study aims to analyze the correlation between radical-left Euroskeptic (RLE) activity and European Union (EU) trade policy by focusing on the Transatlantic Trade and Investment Partnership (TTIP). At the beginning of TTIP negotiations, the agreement was not high on political agendas and was not a major concern within European society. Thus, its salience was low. This initial lack of interest stemmed from the fact that the TTIP, as an economic and technical issue, did not draw public attention. This study shows that RLEs profoundly affected public opinion on the TTIP by increasing its salience during the European parliamentary elections in 2014 in France and Germany. Second, RLEs involv…

Polarization and Spectacle in the Spanish Political Talk Show ‘La Sexta Noche’ During the 2019 European Elections

2021

This article analyses how in the main political talk show on television in Spain, La Sexta Noche, the main themes of the European agenda were silenced or conditioned by the themes of the national, regional and local agenda during the last European elec-tions. The media debate was oriented towards an analysis of the results of national elections and the campaign for regional and local elections that al-lowed for a greater spectacle, thanks to the shock effect of such polarized ideol-ogies and the trivialization of national politics. This research has studied all the shows of the programme broad-cast as of the national elections on 28th April 2019 up until the European elections held on 26th …

Correction of cavity-induced errors in polarization charges of continuum solvation models

1998

POLARIZATION-BASED CAR DETECTION

2018

International audience; Road scene understanding is a vital task for driving assistance systems. Robust vehicle detection is a precondition for diverse applications particularly for obstacle avoidance and secure navigation. Color images provide limited information about the physical properties of the object. This results in unstable vehicle detection caused mainly from road scene complexity (strong reflexions, noises and radiometric distortions). Instead, polarimetric images, characteristic of the light wave, can robustly describe important physical properties of the object (e.g., the surface geometric structure, material and roughness etc). This modality gives rich physical informations wh…

Robustness of 40 Gb/s ASK modulation formats in the practical system infrastructure.

2006

In this work, we analyzed by means of numerical and laboratory experiments the resilience of 40 Gb/s amplitude shift keying modulation formats to transmission impairments in standard single-mode fiber lines as well as to optical filtering introduced by the optical add/drop multiplexer cascade. Our study is a pre-requisite to assess the implementation of cost-effective 40 Gb/s modulation technology in next generation high bit-rate robust optical transport networks. © 2006 Optical Society of America.

Multi-level optimization of a fiber transmission system via nonlinearity management

2006

Nonlinearity management is explored as a complete tool to obtain maximum transmission reach in a WDM fiber transmission system, making it possible to optimize multiple system parameters, including optimal dispersion pre-compensation, with fast simulations based on the continuous-wave approximation. © 2006 Optical Society of America.