TY  - JOUR
A1  - Filacchione, Gianrico
A1  - Groussin, Olivier
A1  - Herny, Clemence
A1  - Kappel, David
A1  - Mottola, Stefano
A1  - Oklay, Nilda
A1  - Pommerol, Antoine
A1  - Wright, Ian
A1  - Yoldi, Zurine
A1  - Ciarniello, Mauro
A1  - Moroz, Lyuba
A1  - Raponi, Andrea
T1  - Comet 67P/CG Nucleus Composition and Comparison to Other Comets
JF  - Space science reviews
N2  - We review our current knowledge of comet 67P/Churyumov–Gerasimenko nucleus composition as inferred from measurements made by remote sensing and in-situ instruments aboard Rosetta orbiter and Philae lander. Spectrophotometric properties (albedos, color indexes and Hapke parameters) of 67P/CG derived by Rosetta are discussed in the context of other comets previously explored by space missions. Composed of an assemblage made of ices, organic materials and minerals, cometary nuclei exhibit very dark and red surfaces which can be described by means of spectrophotometric quantities and reproduced with laboratory measurements. The presence of surface water and carbon dioxide ices was found by Rosetta to occur at localized sites where the activity driven by solar input, gaseous condensation or exposure of pristine inner layers can maintain these species on the surface. Apart from these specific areas, 67P/CG’s surface appears remarkably uniform in composition with a predominance of organic materials and minerals. The organic compounds contain abundant hydroxyl group and a refractory macromolecular material bearing aliphatic and aromatic hydrocarbons. The mineral components are compatible with a mixture of silicates and fine-grained opaques, including Fe-sulfides, like troilite and pyrrhotite, and ammoniated salts. In the vicinity of the perihelion several active phenomena, including the erosion of surface layers, the localized activity in cliffs, fractures and pits, the collapse of overhangs and walls, the transfer and redeposition of dust, cause the evolution of the different regions of the nucleus by inducing color, composition and texture changes.
KW  - Comets
KW  - Composition
KW  - Ices
KW  - Organic matter
KW  - Minerals
Y1  - 2019
U6  - https://doi.org/10.1007/s11214-019-0580-3
SN  - 0038-6308
SN  - 1572-9672
VL  - 215
IS  - 19
PB  - Springer
CY  - Dordrecht
ER  - 
TY  - JOUR
A1  - Lecourieux, Fatma
A1  - Kappel, Christian
A1  - Lecourieux, David
A1  - Serrano, Alejandra
A1  - Torres, Elizabeth
A1  - Arce-Johnson, Patricio
A1  - Delrot, Serge
T1  - An update on sugar transport and signalling in grapevine
JF  - Journal of experimental botany
N2  - In addition to their role as a source of reduced carbon, sugars may directly or indirectly control a wide range of activities in plant cells, through transcriptional and post-translational regulation. This control has been studied in detail using Arabidopsis thaliana, where genetic analysis offers many possibilities. Much less is known about perennial woody species. For several years, various aspects of sugar sensing and signalling have been investigated in the grape (Vitis vinifera L.) berry, an organ that accumulates high concentrations of hexoses in the vacuoles of flesh cells. Here we review various aspects of this topic: the molecular basis of sugar transport and its regulation by sugars in grapevine; the functional analysis of several sugar-induced genes; the effects of some biotic and abiotic stresses on the sugar content of the berry; and finally the effects of exogenous sugar supply on the ripening process in field conditions. A picture of complex feedback and multiprocess regulation emerges from these data.
KW  - Fruit biology
KW  - grapevine
KW  - signalling
KW  - stress
KW  - sugar
KW  - transport
Y1  - 2014
U6  - https://doi.org/10.1093/jxb/ert394
SN  - 0022-0957
SN  - 1460-2431
VL  - 65
IS  - 3
SP  - 821
EP  - 832
PB  - Oxford Univ. Press
CY  - Oxford
ER  -