Search results for "init"

SrP3N5O: a highly condensed layer phosphate structure solved from a nanocrystal by automated electron diffraction tomography.

2011

The oxonitridophosphate SrP(3)N(5)O has been synthesized by heating a multicomponent reactant mixture that consisted of phosphoryl triamide OP(NH(2))(3), thiophosphoryl triamide SP(NH(2))(3), SrS, and NH(4)Cl enclosed in evacuated and sealed silica-glass ampoules up to 750 °C. The compound was obtained as nanocrystalline powder with needle-shaped crystallites. The crystal structure was solved ab initio on the basis of electron diffraction data by means of automated electron diffraction tomography (ADT) and verified by Rietveld refinement with X-ray powder diffraction data. SrP(3)N(5)O crystallizes in the orthorhombic space group Pnma (no. 62) with unit-cell data of a=18.331(2), b=8.086(1), …

Observe while it happens : catching photoactive proteins in the act with non-adiabatic molecular dynamics simulations

2020

Organisms use photo-receptors to react to light. The first step is usually the absorption of a photon by a prosthetic group embedded inside the photo-receptor, often a conjugated chromophore. The electronic changes in the chromophore induced by photo-absorption can trigger a cascade of structural or chemical transformations that culminate into a response to light. Understanding how these proteins have evolved to mediate their activation process has remained challenging because the required time and spacial resolutions are notoriously difficult to achieve experimentally. Therefore, mechanistic insights into photoreceptor activation have been predominantly obtained with computer simulations. …

Applications of Quantum Chemistry in Spectroscopy: Molecules, Complexes of Van der Waals, trapped Molecules

2009

I described in this memory my activities as a researcher at Tomsk well before 2003, in succession to the State University of Tomsk in the Faculty of Physics, Institute of Physics of Siberia, and the Institute of 'Atmospheric Optics, in France since then, mostly at the University of Bourgogne (ICB), but also at the University of Lille I (PhLAM) and the University of Marne-la-Vallée (LCT). Part of my work has been dedicated to the evaluation by calculating ab initio of rovibrational constants for quasi-spherical molecules. The centrifugal distortion constants and the dipole moment of the molecule SO2F2 were calculated to validate the tensor theory and interpreter the spectrum. I twas shown th…

Protonation of the Biliverdin IXα Chromophore in the Red and Far-Red Photoactive States of Bacteriophytochrome

2019

The tetrapyrrole chromophore biliverdin IXα (BV) in the bacteriophytochrome from Deinococcus radiodurans (DrBphP) is usually assumed to be fully protonated, but this assumption has not been systematically validated by experiments or extensive computations. Here, we use force field molecular dynamics simulations and quantum mechanics/molecular mechanics calculations with density functional theory and XMCQDPT2 methods to investigate the effect of the five most probable protonation forms of BV on structural stability, binding pocket interactions, and absorption spectra in the two photochromic states of DrBphP. While agreement with X-ray structural data and measured UV/vis spectra suggest that …

Red Light Optogenetics in Neuroscience

2022

Optogenetics, a field concentrating on controlling cellular functions by means of light-activated proteins, has shown tremendous potential in neuroscience. It possesses superior spatiotemporal resolution compared to the surgical, electrical, and pharmacological methods traditionally used in studying brain function. A multitude of optogenetic tools for neuroscience have been created that, for example, enable the control of action potential generation via light-activated ion channels. Other optogenetic proteins have been used in the brain, for example, to control long-term potentiation or to ablate specific subtypes of neurons. In in vivo applications, however, the majority of optogenetic too…

The Interconnecting Hairpin Extension "Arm": An Essential Allosteric Element of Phytochrome Activity

2023

In red-light sensing phytochromes, isomerization of the bilin chromophore triggers structural and dynamic changes across multiple domains, ultimately leading to control of the output module (OPM) activity. In between, a hairpin structure, "arm", extends from an interconnecting domain to the chromophore region. Here, by removing this protein segment in a bacteriophytochrome from Deinococcus radiodurans (DrBphP), we show that the arm is crucial for signal transduction. Crystallographic, spectroscopic, and biochemical data indicate that this variant maintains the properties of DrBphP in the resting state. Spectroscopic data also reveal that the armless systems maintain the ability to respond t…

Jokseenkin toisenlainen Nälkämaanlaulu : kauneuskulttuurin anorektisen asenteen tarkastelua suhteessa uskonnolliseen itsekieltäymykseen ja yleiseen m…

1999

Estudios estratégicos para la lucha contra la fascioliasis humana a nivel mundial = Strategic studies for the fight against de human fascioliasis wor…

2013

Fascioliasis is a zoonotic parasitic disease caused by Fasciola hepatica and F. gigantica. Emergence of human fascioliasis prompted a worldwide control initiative including a pilot study in several countries. Given the necessity to characterize the fasciolid populations involved, the overall aim of the present research is, first, the phenotypic characterization of faciolid adults and eggs implicated in human endemic areas, where this initiative has been implemented, through a computer image analysis system (CIAS) applied on the basis of standardized measurements. Second, new immunological techniques and their potential use as immunological diagnostic tests in those areas are evaluated. The …

L’affresco con la Virgo lactans “in maestà” e la Trinità tricefala: un’opera castigliana?

2023

Nel saggio si approfondisce la lettura iconografica di un affresco tardo-gotico dell'ultimo quarto del XV secolo conservato nella chiesa di Santa Maria la Porta di Geraci Siculo (PA). La Madonna che allatta il Bambino, il tipo di trono architettonico in cui è posta e la presenza della rara iconografia della Trinità tricefala suggeriscono una matrice iberica, probabilmente castigliana The essay explores the iconographic interpretation of a late Gothic fresco from the last quarter of the 15th century preserved in the church of Santa Maria la Porta in Geraci Siculo (PA). The Madonna suckling the Child, the type of architectural throne on which she is placed and the presence of the rare iconogr…

De participació local. Una proposta metodològica desde la investigació-acció-participativa

2018

Citizen participation is an increasingly prevalent term in our society. In the process of deployment in the municipal area, progressively local corporations make efforts to innovate practices and develop experiences of citizen participation in defining policies and public affairs, and allocating budgets. While innovation has been advanced with regard to the tools and mechanisms to be used to promote participation, many of the initiatives and experiences have focused more on the implementation of the vote than in the different social processes inherent in the participation. Moreover, we are faced with the absence of a methodological guide that allows approaching a project or strategic plan o…