Synchronization in complex networks

Synchronization processes in populations of locally interacting elements are in the focus of intense research in physical, biological, chemical, technological and social systems. The many efforts devoted to understand synchronization phenomena in natural systems take now advantage of the recent theory of complex networks. In this review, we report the advances in the comprehension of synchronization phenomena when oscillating elements are constrained to interact in a complex network topology. We also overview the new emergent features coming out from the interplay between the structure and the function of the underlying pattern of connections. Extensive numerical work as well as analytical approaches to the problem are presented. Finally, we review several applications of synchronization in complex networks to different disciplines: biological systems and neuroscience, engineering and computer science, and economy and social sciences.Comment: Final version published in Physics Reports. More information available at http://synchronets.googlepages.com

Hyperserotonemia in Adults with Autistic Disorder

Abstract Hyperserotonemia is the most consistent serotonin-related finding in autism. The basis of this phenomenon, and its relationship to the central serotonergic dysfunction remains unclear. Platelet serotonin level (PSL) in 53 autistic adults and 45 healthy controls was measured. Mean PSL in autistic group (75.7 ± 37.4 ng/lL) was significantly higher than the control sample (59.2 ± 16.2 ng/lL) due to a presence of hyperserotonemic subjects which comprised 32% of the patients. PSL of autistic subjects did not correlate with the severity of symptoms, as measured by total CARS score, or the degree of mental retardation. However, significant negative relationship was observed between PSL and speech development, indicating the relationship between the peripheral 5HT concentrations and verbal abilities in autistic subjects

Evolutionary Analysis of DELLA-Associated Transcriptional Networks

[EN] DELLA proteins are transcriptional regulators present in all land plants which have been shown to modulate the activity of over 100 transcription factors in Arabidopsis, involved in multiple physiological and developmental processes. It has been proposed that DELLAs transduce environmental information to pre-wired transcriptional circuits because their stability is regulated by gibberellins (GAs), whose homeostasis largely depends on environmental signals. The ability of GAs to promote DELLA degradation coincides with the origin of vascular plants, but the presence of DELLAs in other land plants poses at least two questions: what regulatory properties have DELLAs provided to the behavior of transcriptional networks in land plants, and how has the recruitment of DELLAs by GA signaling affected this regulation. To address these issues, we have constructed gene co-expression networks of four different organisms within the green lineage with different properties regarding DELLAs: Arabidopsis thaliana and Solanum lycopersicum (both with GA- regulated DELLA proteins), Physcomitrella patens (with GA- independent DELLA proteins) and Chlamydomonas reinhardtii (a green alga without DELLA), and we have examined the relative evolution of the subnetworks containing the potential DELLA-dependent transcriptomes. Network analysis indicates a relative increase in parameters associated with the degree of interconnectivity in the DELLA-associated subnetworks of land plants, with a stronger effect in species with GA- regulated DELLA proteins. These results suggest that DELLAs may have played a role in the coordination of multiple transcriptional programs along evolution, and the function of DELLAs as regulatory 'hubs' became further consolidated after their recruitment by GA signaling in higher plants.Work in the laboratories was funded by grants BFU2016-80621-P and BIO2014-52425-P of the Spanish Ministry of Economy, Industry and Competitiveness, and H2020-MSCA-RISE-2014-644435 of the European Union. AB-M and JH-G hold Fellowships of the Spanish Ministry of Education, Culture and Sport FPU14/01941 and FPU15/01756, respectively.Briones-Moreno, A.; Hernández-García, J.; Vargas-Chávez, C.; Romero-Campero FJ; Romero, J.; Valverde, F.; Blazquez Rodriguez, MA. (2017). Evolutionary Analysis of DELLA-Associated Transcriptional Networks. Frontiers in Plant Science. 8(626):1-11. https://doi.org/10.3389/fpls.2017.00626S111862

Community landscapes: an integrative approach to determine overlapping network module hierarchy, identify key nodes and predict network dynamics

Background: Network communities help the functional organization and evolution of complex networks. However, the development of a method, which is both fast and accurate, provides modular overlaps and partitions of a heterogeneous network, has proven to be rather difficult. Methodology/Principal Findings: Here we introduce the novel concept of ModuLand, an integrative method family determining overlapping network modules as hills of an influence function-based, centrality-type community landscape, and including several widely used modularization methods as special cases. As various adaptations of the method family, we developed several algorithms, which provide an efficient analysis of weighted and directed networks, and (1) determine pervasively overlapping modules with high resolution; (2) uncover a detailed hierarchical network structure allowing an efficient, zoom-in analysis of large networks; (3) allow the determination of key network nodes and (4) help to predict network dynamics. Conclusions/Significance: The concept opens a wide range of possibilities to develop new approaches and applications including network routing, classification, comparison and prediction.Comment: 25 pages with 6 figures and a Glossary + Supporting Information containing pseudo-codes of all algorithms used, 14 Figures, 5 Tables (with 18 module definitions, 129 different modularization methods, 13 module comparision methods) and 396 references. All algorithms can be downloaded from this web-site: http://www.linkgroup.hu/modules.ph

Frenkel exciton model of excitation and recombination processes in crystalline alpha-PTCDA

Fuer anorganische Kristalle werden die chemischen Bindungen durch kovalente oder ionische Beitraege dominiert. Im Gegensatz dazu stehen organische Molekuelkristalle, in denen in jedem der Molekuele starke kovalente Bindungen vorherrschen, waehrend die Molekuele untereinander nur relativ schwache Wechselwirkung zeigen. Daher sind die Veraenderungen zwischen den Spektren freier Molekuele und den entsprechenden Kristallen wesentlich geringer als die zwischen einem freien Atom und einem anorganischen Kristall. In einem organischen Kristall kann eine optisch erzeugte elektronische Anregung zwischen verschiedenen Molekuelen transferiert werden. Fuer das Modellsystem PTCDA (3,4,9,10-Perylentetracarbonsaeuredianhydrid) wurden die elektronischen und vibronischen Spektren analysiert und die aus dem Transfer der Anregung resultierende exzitonische Bandstruktur untersucht. Die optische Absorption erzeugt ein Frenkel-Exziton am Dispersionsmaximum in der Naehe des Gamma-Punktes in der Brillouin-Zone. Durch inelastische Streuvorgaenge relaxiert dieses Exziton zum Dispersionsminimum am Rand der Brillouin-Zone. Die Photolumineszenz bei tiefen Temperaturen entsteht daraus durch vertikale Rekombination, wobei der Endzustand eine vibronische Anregung mit endlichem Quasi-Impuls enthaelt. Die berechnete strahlende Rekombinationsrate und die Linienform der Photolumineszenzbande stimmen dabei gut mit den experimentellen Ergebnissen ueberein. Das Modell des Exzitonentransfers im Volumenmaterial kann auf Filme endlicher Dicke verallgemeinert werden, so dass sich die veraenderten optischen Eigenschaften duenner Filme beschreiben lassen. Durch die endliche Zahl der molekularen Monolagen in einem solchen Film ist das energetische Spektrum diskret, wobei die Einhuellenden der exzitonischen Wellenfunktionen entlang der Quantisierungsrichtung an die Zustaende in einem Quantentrog mit unendlich hohen Barrieren erinnern. Das Zusammenspiel von geometrischer Randbedingung und energetischer Lage des molekularen uebergangs in der Randschicht kann sowohl zu einer Rot- als auch zu einer Blauverschiebung der optischen Antwort fuehren

Frenkel exciton model of excitation and recombination processes in crystalline alpha-PTCDA

Fuer anorganische Kristalle werden die chemischen Bindungen durch kovalente oder ionische Beitraege dominiert. Im Gegensatz dazu stehen organische Molekuelkristalle, in denen in jedem der Molekuele starke kovalente Bindungen vorherrschen, waehrend die Molekuele untereinander nur relativ schwache Wechselwirkung zeigen. Daher sind die Veraenderungen zwischen den Spektren freier Molekuele und den entsprechenden Kristallen wesentlich geringer als die zwischen einem freien Atom und einem anorganischen Kristall. In einem organischen Kristall kann eine optisch erzeugte elektronische Anregung zwischen verschiedenen Molekuelen transferiert werden. Fuer das Modellsystem PTCDA (3,4,9,10-Perylentetracarbonsaeuredianhydrid) wurden die elektronischen und vibronischen Spektren analysiert und die aus dem Transfer der Anregung resultierende exzitonische Bandstruktur untersucht. Die optische Absorption erzeugt ein Frenkel-Exziton am Dispersionsmaximum in der Naehe des Gamma-Punktes in der Brillouin-Zone. Durch inelastische Streuvorgaenge relaxiert dieses Exziton zum Dispersionsminimum am Rand der Brillouin-Zone. Die Photolumineszenz bei tiefen Temperaturen entsteht daraus durch vertikale Rekombination, wobei der Endzustand eine vibronische Anregung mit endlichem Quasi-Impuls enthaelt. Die berechnete strahlende Rekombinationsrate und die Linienform der Photolumineszenzbande stimmen dabei gut mit den experimentellen Ergebnissen ueberein. Das Modell des Exzitonentransfers im Volumenmaterial kann auf Filme endlicher Dicke verallgemeinert werden, so dass sich die veraenderten optischen Eigenschaften duenner Filme beschreiben lassen. Durch die endliche Zahl der molekularen Monolagen in einem solchen Film ist das energetische Spektrum diskret, wobei die Einhuellenden der exzitonischen Wellenfunktionen entlang der Quantisierungsrichtung an die Zustaende in einem Quantentrog mit unendlich hohen Barrieren erinnern. Das Zusammenspiel von geometrischer Randbedingung und energetischer Lage des molekularen uebergangs in der Randschicht kann sowohl zu einer Rot- als auch zu einer Blauverschiebung der optischen Antwort fuehren

Red de Docencia en Ingeniería Acústica

Elaboración de materiales curriculares para el desarrollo de las guías docentes en la docencia presencial y no presencial de materias en el área de la Ingeniería Acústica

Intensive Care Nurses’ Perceptions of Routine Dyspnea Assessment

Background Dyspnea (breathing discomfort) is commonly experienced by critically ill patients and at this time is not routinely assessed and documented. Intensive care unit nurses at the study institution recently instituted routine assessment and documentation of dyspnea in all patients able to report using a numeric scale ranging from 0 to 10. Objective To assess nurses’ perceptions of the utility of routine dyspnea measurement, patients’ comprehension of assessment questions, and the impact on nursing practice and to gather nurses’ suggestions for improvement. Methods Data were obtained from interviews with intensive care unit nurses in small focus groups and an anonymous online survey randomly distributed to nurses representing all intensive care units. Results Intensive care unit nurses affirmed the importance of routine dyspnea assessment and documentation. Before implementing the measurement tool, nurses often assessed for breathing discomfort in patients by using observed signs. Most nurses agreed that routine assessment can be used to predict patients’ outcomes and improve patient-centered care. Nurses found the assessment tool easy to use and reported that it did not interfere with workflow. Nurses felt that patients were able to provide meaningful ratings of dyspnea, similar to ratings of pain, and often used patients’ ratings in conjunction with observed physical signs to optimize patient care. Conclusion Our study shows that nurses understand the importance of routine dyspnea assessment and that the addition of a simple patient report scale can improve care delivery and does not add to the burden of work-flow. </jats:sec