Choose an application

• Reference Manager
• EndNote
• RefWorks (Direct export to RefWorks)

Beaufort Sea --- Mackenzie Trough

Choose an application

• Reference Manager
• EndNote
• RefWorks (Direct export to RefWorks)

Beaufort Sea --- Mackenzie Trough --- Arctic Coast (Alaska)

Choose an application

• Reference Manager
• EndNote
• RefWorks (Direct export to RefWorks)

Geology --- Hydrothermal vents --- Hydrothermal vent animals --- Escanaba Trough. --- Pacific Ocean

Choose an application

• Reference Manager
• EndNote
• RefWorks (Direct export to RefWorks)

Since the 50s, the massive and “environmental naïve” use of synthetic chemistry has revolutionized the farming community facing the dramatic growth of demography. However, nowadays the controversy grows about the long-term harmful effects of these products on human health and the environment. In this context, the use of essential oils (EOs) could be an alternative to chemical products. To develop EOs as bioherbicides, a better understanding of their mode of biological action for new and optimal applications is of importance. Indeed, if the biocidal effects of some EOs or their components have been at least partly elucidated at the molecular level, very little is currently known about their mechanism of action as herbicides at the molecular level. 
In a previous study, the cinnamon and Java citronella essential oils and their main components, cinnamaldehyde (CIN), citronellal (CitA) and citronellol (CitO) were shown to be efficient herbicides. The individual EO molecules are small amphiphiles allowing them to cross the mesh of cell wall and interact directly with the plant plasma membrane (PPM), one of the potential cellular targets of EOs.
We used here an integrative biophysical approach combining Molecular Dynamics, Isothermal Titration Calorimetry and Langmuir trough to investigate and characterise the interaction between CIN, CitA and CitO and biomimetic PPM. We showed that if CitO and CitA having a similar chemical structure, are able to interact with the model membranes without permeabilizing effect, CIN belonging to the phenylpropanoid family, is not. We suggested that different mechanisms of action for the two types of molecules can occur: while the monoterpenes could disturb the lipid organization and/or domain formation, the phenylpropanoid CIN could interact with membrane receptors. Depuis les années 50, l'utilisation massive et "naïve" de la chimie de synthèse a révolutionné le monde agricole face à la forte croissance démographique. Cependant, la controverse grandit sur les effets nocifs à long terme de ces produits sur la santé humaine et sur l'environnement. Dans ce contexte, l'utilisation des huiles essentielles (EO) pourrait être une alternative aux produits chimiques. Pour cela, une meilleure compréhension de leur mode d'action biologique pour des applications nouvelles et optimales est importante. En effet, si les effets biocides de certaines EO ou de leurs composants ont été au moins partiellement élucidés, on en sait actuellement très peu sur leur mécanisme d'action en tant qu'herbicides au niveau moléculaire.
Dans une étude précédente, les huiles essentielles de cannelle et de citronnelle et leurs principaux composants, le cinnamaldéhyde (CIN), le citronellal (CitA) et le citronellol (CitO) se sont révélés efficaces comme herbicides. Les molécules d'EO sont de petits amphiphiles qui peuvent traverser le maillage de la paroi cellulaire et interagir directement avec la membrane plasmique végétale (PPM), l'une des cibles cellulaires potentielles des EO.
Nous avons utilisé ici une approche biophysique intégrative combinant la dynamique moléculaire, la calorimétrie par titrage isotherme et la cuve de Langmuir pour étudier et caractériser l'interaction entre CIN, CitA et CitO et la PPM biomimétique. Nous avons montré que si CitO et CitA ayant une structure chimique similaire, sont capables d'interagir avec les membranes du modèle sans effet de perméabilisation, CIN appartenant à la famille des phénylpropanoïdes, en est incapable. Nous avons suggéré différents mécanismes d'action possible pour les deux types de molécules : alors que les monoterpènes pourraient perturber l'organisation lipidique et/ou la formation de domaines, les CIN phénylpropanoïdes pourraient interagir avec des récepteurs membranaires.

Molecular Dynamics --- essential oils --- cinnamaldehyde --- citronellol --- citronellal --- Langmuir trough --- ITC --- huiles essentielles --- Dynamique Moléculaire --- Ingénierie, informatique & technologie > Sciences informatiques

Choose an application

• Reference Manager
• EndNote
• RefWorks (Direct export to RefWorks)

This book focuses on the characterization of the physical properties of the Earth’s ionosphere, contributing to unveiling the nature of several processes responsible for a plethora of space weather-related phenomena taking place in a wide range of spatial and temporal scales. This is made possible by the exploitation of a huge amount of high-quality data derived from both remote sensing and in situ facilities such as ionosondes, radars, satellites and Global Navigation Satellite Systems receivers.

Research & information: general --- Geography --- electron temperature --- topside ionosphere --- ESA Swarm satellites --- International Reference Ionosphere model --- Langmuir Probes in-situ data --- Incoherent Scatter Radar data --- GNSS --- GBAS --- ionospheric gradient anomaly --- one class support vector machine --- earthquake --- pre-earthquake anomalies --- swarm satellites --- ionospheric plasma --- deep learning --- physical mechanisms --- τ --- geomagnetic equator --- magnetic storm --- ionosphere --- vertical pulse sounding --- ionosonde --- ionogram --- software-defined radio --- radar imaging --- aspect angle --- field-aligned plasma irregularities --- mid-latitude E region --- norm-constrained Capon --- VHF radar --- plasma turbulence --- ionospheric irregularities --- ionosphere F region --- high latitude --- pressure-gradient current --- diamagnetic current --- swarm measurements --- oblique ionogram --- automatic inversion --- electron density profile --- quasi-parabolic segments --- the sporadic E layer --- internal fine structure --- high-resolution ionosphere imaging --- frequency domain interferometry technique --- auroral ionosphere --- E × B plasma motion --- ionospheric scintillation --- GNSS-R --- CYGNSS --- earthquakes --- polar ionosphere --- VIPIR --- Dynasonde --- Jang Bogo Station (JBS) --- Antarctica --- solar eclipse --- precise point positioning --- total electron content --- rate of total electron content index --- Swarm satellite measurements --- electron density --- main ionospheric trough --- high latitude trough --- ring ionospheric trough --- low latitude trough --- auroral diffuse precipitation --- n/a