Coherent anti-Stokes Raman Fourier ptychography

International audienceWe present a theoretical and numerical study of coherent anti-Stokes Raman scattering Fourier ptychography microscopy (CARS-FPM), a scheme that has not been considered so far in the previously reported CARS wide-field imaging schemes. In this approach, the distribution of the Raman scatterer density of the sample is reconstructed numerically from CARS images obtained under various angles of incidences of the pump or Stokes beam. Our inversion procedure is based on an accurate vectorial model linking the CARS image to the sample and yields both the real and imaginary parts of the susceptibility, the latter giving access to the Raman information, with an improved resolution

Multi-messenger observations of a binary neutron star merger

On 2017 August 17 a binary neutron star coalescence candidate (later designated GW170817) with merger time 12:41:04 UTC was observed through gravitational waves by the Advanced LIGO and Advanced Virgo detectors. The Fermi Gamma-ray Burst Monitor independently detected a gamma-ray burst (GRB 170817A) with a time delay of ~1.7 s with respect to the merger time. From the gravitational-wave signal, the source was initially localized to a sky region of 31 deg2 at a luminosity distance of 40+8-8 Mpc and with component masses consistent with neutron stars. The component masses were later measured to be in the range 0.86 to 2.26 Mo. An extensive observing campaign was launched across the electromagnetic spectrum leading to the discovery of a bright optical transient (SSS17a, now with the IAU identification of AT 2017gfo) in NGC 4993 (at ~40 Mpc) less than 11 hours after the merger by the One- Meter, Two Hemisphere (1M2H) team using the 1 m Swope Telescope. The optical transient was independently detected by multiple teams within an hour. Subsequent observations targeted the object and its environment. Early ultraviolet observations revealed a blue transient that faded within 48 hours. Optical and infrared observations showed a redward evolution over ~10 days. Following early non-detections, X-ray and radio emission were discovered at the transient’s position ~9 and ~16 days, respectively, after the merger. Both the X-ray and radio emission likely arise from a physical process that is distinct from the one that generates the UV/optical/near-infrared emission. No ultra-high-energy gamma-rays and no neutrino candidates consistent with the source were found in follow-up searches. These observations support the hypothesis that GW170817 was produced by the merger of two neutron stars in NGC4993 followed by a short gamma-ray burst (GRB 170817A) and a kilonova/macronova powered by the radioactive decay of r-process nuclei synthesized in the ejecta

Relation structure-fonction dans la racine : effets du squelette parietal sur les transports membranaires

182 ref. *URD-INRA, 2 Place Viala, 34060 Montpellier Cedex 01 (FRA) Diffusion du document : URD-INRA, 2 Place Viala, 34060 Montpellier Cedex 01 (FRA) Diplôme : Dr. d'Universit

Des pompes et des canaux ioniques contrôlant la turgescence cellulaire assurent une capacité de mouvement chez les plantes

Des pompes et des canaux ioniques contrôlant la turgescence cellulaire assurent une capacité de mouvement chez les plantes. Journée de la Société de Biologie de Montpellier : "Le mouvement dans tous ses états

A Model for Predicting Ionic Equilibrium Concentrations in Cell Walls

Purified cell walls were prepared from roots of Horse bean (Vicia faba L., var. minor) and Yellow Lupine (Lupinus luteus L.). Two methods were used: (a) grinding and (b) lysis of the endocellular contents by Triton X-100. The Ca(2+), Mg(2+), and K(+) contents were determined after incubation in various solutions in such a manner that the measurements gave access to the undisturbed equilibrium contents. The results were used to test a model which describes the ionic atmosphere in the cell walls as a result of simultaneous electrostatic interactions between free ions (Donnan effect) and specific association equilibria, including acido-basic ones. This model correctly accounted for the whole set of experimental results and predicted the values of the unmeasurable local concentrations and pH

PH and ionic conditions in the apoplast

International audienc

Potassium nutrition in plants under low K+ availability: from sensing and signalling to regulation of membrane transport activity and root development

Potassium nutrition in plants under low K+ availability: from sensing and signalling to regulation of membrane transport activity and root development. Society of Experimental Biology Annual Main Meeting 2013 (SEB 2013

Effet du pH sur l'absorption de l'orthophosphate par les racines de mais.

International audienc