Simulation of photo-excited adenine in water with a hierarchy of equations of motion approach

We present a theoretical method to simulate the electronic dynamics and two-dimensional ultraviolet spectra of the nucleobase adenine in water. The method is an extension of the hierarchy of equation of motion approach to treat a model with one or more conical intersections. The application to adenine shows that a two-level model with a direct conical intersection between the optically bright state and the ground state, generating a hot ground state, is not consistent with experimental observations. This supports a three-level model for the decay of electronically excited adenine in water as was previously proposed in [Prokhorenko et al., J. Phys. Chem. Lett. 7, 4445 (2016)]

Interference of multi-mode photon echoes generated in spatially separated solid-state atomic ensembles

High-visibility interference of photon echoes generated in spatially separated solid-state atomic ensembles is demonstrated. The solid state ensembles were LiNbO$_3$ waveguides doped with Erbium ions absorbing at 1.53 $\mu$m. Bright coherent states of light in several temporal modes (up to 3) are stored and retrieved from the optical memories using two-pulse photon echoes. The stored and retrieved optical pulses, when combined at a beam splitter, show almost perfect interference, which demonstrates both phase preserving storage and indistinguishability of photon echoes from separate optical memories. By measuring interference fringes for different storage times, we also show explicitly that the visibility is not limited by atomic decoherence. These results are relevant for novel quantum repeaters architectures with photon echo based multimode quantum memories

Komplexe interozeptive Veränderungen bei Essstörungen: Eine Untersuchung physiologischer, behavioraler, kognitiver und emotionaler Aspekte kardialer Interozeption

peer reviewedEinleitung Interozeption bezeichnet die Wahrnehmung von Signalen aus dem Körperinneren. Sie wird seit langem als transdiagnostischer ätiologischer Faktor für Essstörungen diskutiert. Der Annahme einer generell reduzierten Interozeptionsfähigkeit bei Essstörungen stehen rezent gemischte Befunde gegenüber. Problematisch in vorhandenen Studien ist die Beschränkung auf einzelne Aspekte der Interozeption und einzelne Diagnosegruppen. Um diese Schwächen zu überwinden, untersuchte die vorliegende Studie physiologische, behaviorale, kognitive und emotionale Aspekte der Herzschlagwahrnehmung bei Anorexia nervosa (AN), Bulimia nervosa (BN) und Kontrollpersonen ohne Essstörung. Methoden Bei 146 Teilnehmerinnen (AN = 38, BN = 35, Kontrollpersonen = 73) wurden während einer Ruhephase und einer Herzschlagwahrnehmungsaufgabe EKG und EEG abgeleitet. Ausgewertet wurden Herzschlag-evozierte Hirnpotenziale (zentralnervöse Verarbeitung kardialer Reize; physiologisch), Herzschlagwahrnehmung (interozeptive Akkuranz; behavioral), Vertrauen in die eigene Herzschlagwahrnehmung (interozeptive Sensibilität; kognitiv) und die emotionale Bewertung der Herzschlagwahrnehmung. Ergebnisse Patientinnen mit AN wiesen höhere Herzschlag-evozierte Hirnpotenziale auf; Patientinnen mit AN und BN bewerteten die Herzschlagwahrnehmung negativer als die Kontrollgruppe. Für die Herzschlagwahrnehmung und das Vertrauen darin ergaben sich keine signifikanten Gruppenunterschiede. Schlussfolgerung Anstatt eines übergreifenden interozeptiven Defizits ergab sich ein komplexes Bild interozeptiver Veränderungen. Bei unveränderter Herzschlagwahrnehmung wiesen Patientinnen mit AN eine verstärkte zentralnervöse Verarbeitung des Herzschlags auf. Beide Essstörungsgruppen erlebten die Herzschlagwahrnehmung als aversiv. Explorative Korrelationsanalysen legten einen Zusammenhang von verstärkter und aversiver interozeptiver Verarbeitung mit Ängstlichkeit nahe. Essgestörtes Verhalten könnte der Unterdrückung aversiver Körperempfindungen und Emotionen dienen. Eine multidimensionale Betrachtung von Interozeption ist unerlässlich für die Entwicklung von ätiologischen Modellen und Behandlungsansätzen.3. Good health and well-bein

Colored Motifs Reveal Computational Building Blocks in the C. elegans Brain

Background: Complex networks can often be decomposed into less complex sub-networks whose structures can give hints about the functional organization of the network as a whole. However, these structural motifs can only tell one part of the functional story because in this analysis each node and edge is treated on an equal footing. In real networks, two motifs that are topologically identical but whose nodes perform very different functions will play very different roles in the network. Methodology/Principal Findings: Here, we combine structural information derived from the topology of the neuronal network of the nematode C. elegans with information about the biological function of these nodes, thus coloring nodes by function. We discover that particular colorations of motifs are significantly more abundant in the worm brain than expected by chance, and have particular computational functions that emphasize the feed-forward structure of information processing in the network, while evading feedback loops. Interneurons are strongly over-represented among the common motifs, supporting the notion that these motifs process and transduce the information from the sensor neurons towards the muscles. Some of the most common motifs identified in the search for significant colored motifs play a crucial role in the system of neurons controlling the worm's locomotion. Conclusions/Significance: The analysis of complex networks in terms of colored motifs combines two independent data sets to generate insight about these networks that cannot be obtained with either data set alone. The method is general and should allow a decomposition of any complex networks into its functional (rather than topological) motifs as long as both wiring and functional information is available

Quantifying non-Markovianity in underdamped versus overdamped environments and its effect on spectral lineshape

Non-Markovian effects in open quantum systems are central to understanding spectral lineshape. Here, we quantify the non-Markovianity associated with both overdamped and underdamped vibrations in terms of information flow between the bath and the system and compare this with the broadening and ellipticity of two-dimensional spectra. Using the Breuer Laine Piilo (BLP) measure, we link the well-known stochastic models for spectral lineshape with modern quantum information theory. Specifically, we study the effect of non-Markovianity in a system in contact with underdamped vibrations and examine the differences observed on increasing the damping to the overdamped limit. The open quantum system dynamics are evolved using the hierarchical equations of motion, efficiently terminated with a Markovian cutoff, where separate hierarchies are derived for the underdamped and overdamped environments. It is shown that the BLP measure is quantitatively correlated with the ellipticity of two-dimensional spectra and memory effects are more pronounced in underdamped environments, due to the long-lived feedback of information between the system and its bath, compared to overdamped environments. Environmental signatures in spectral lineshapes emerge as a result of information flow from the bath back into the system