Search results for "state transitions"

showing 2 items of 2 documents

Functional rearrangement of the light-harvesting antenna upon state transitions in a green alga

2014

AbstractState transitions in the green alga Chlamydomonas reinhardtii serve to balance excitation energy transfer to photosystem I (PSI) and to photosystem II (PSII) and possibly play a role as a photoprotective mechanism. Thus, light-harvesting complex II (LHCII) can switch between the photosystems consequently transferring more excitation energy to PSII (state 1) or to PSI (state 2) or can end up in LHCII-only domains. In this study, low-temperature (77 K) steady-state and time-resolved fluorescence measured on intact cells of Chlamydomonas reinhardtii shows that independently of the state excitation energy transfer from LHCII to PSI or to PSII occurs on two main timescales of <15 ps and …

0106 biological sciencesPhotosystem IIEnergy transferBiophysicsLight-Harvesting Protein ComplexesphotosystemChlamydomonas reinhardtiiPhotosystem IPhotochemistry01 natural sciences03 medical and health sciencesstate transitionsgreen algaSDG 7 - Affordable and Clean Energy030304 developmental biologyPhotosystem0303 health sciencesenergy transfer/dk/atira/pure/sustainabledevelopmentgoals/affordable_and_clean_energybiologyPhotosystem I Protein ComplexChemistryta1182Photosystem II Protein ComplexState (functional analysis)biology.organism_classificationFluorescenceCell BiophysicsAtomic physicsExcitationChlamydomonas reinhardtii010606 plant biology & botanyBiophysical journal
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Electron-density critical points analysis and catastrophe theory to forecast structure instability in periodic solids

2018

The critical points analysis of electron density,i.e. ρ(x), fromab initiocalculations is used in combination with the catastrophe theory to show a correlation between ρ(x) topology and the appearance of instability that may lead to transformations of crystal structures, as a function of pressure/temperature. In particular, this study focuses on the evolution of coalescing non-degenerate critical points,i.e. such that ∇ρ(xc) = 0 and λ1, λ2, λ3≠ 0 [λ being the eigenvalues of the Hessian of ρ(x) atxc], towards degenerate critical points,i.e. ∇ρ(xc) = 0 and at least one λ equal to zero. The catastrophe theory formalism provides a mathematical tool to model ρ(x) in the neighbourhood ofxcand allo…

Hessian matrixElectron densitycatastrophe theory010504 meteorology & atmospheric sciencesCondensed Matter Physic010502 geochemistry & geophysics01 natural sciencesBiochemistryInstabilityInorganic Chemistrysymbols.namesakeStructural BiologyAb initio quantum chemistry methodsGeneral Materials Sciencephase/state transitions in crystalPhysical and Theoretical Chemistryphase/state transitions in crystalsEigenvalues and eigenvectors0105 earth and related environmental sciencesPhysicsab initio calculationelectron-density critical pointCondensed matter physicsab initio calculationsDegenerate energy levelsCondensed Matter PhysicsGibbs free energyelectron-density critical points catastrophe theory phase/state transitions in crystals ab initio calculations.symbolsMaterials Science (all)Catastrophe theoryelectron-density critical points
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