Consistency of heterogeneous synchronization patterns in complex weighted networks

Synchronization within the dynamical nodes of a complex network is usually considered homogeneous through all the nodes. Here we show, in contrast, that subsets of interacting oscillators may synchronize in different ways within a single network. This diversity of synchronization patterns is promoted by increasing the heterogeneous distribution of coupling weights and/or asymmetries in small networks. We also analyze consistency, defined as the persistence of coexistent synchronization patterns regardless of the initial conditions. Our results show that complex weighted networks display richer consistency than regular networks, suggesting why certain functional network topologies are often constructed when experimental data are analyzed. Dynamical systems may synchronize in several ways, at the same time, when they are coupled in a single complex network. Examples of this diversity of synchronization patterns may be found in research fields as diverse as neuroscience, climate networks, or ecosystems. Here we report the conditions required to obtain coexisting synchronizations in arrangements of interacting chaotic oscillators, and relate these conditions to the distribution of coupling weights and asymmetries in complex networks. We also analyze the conditions required for a high statistical occurrence of the same synchronization patterns, regardless of the oscillators' initial conditions. Our results show that these persistent synchronization patterns are statistically more frequent in complex weighted networks than in regular ones, explaining why certain functional network topologies are often retrieved from experimental data. Besides, our results suggest that considering both the different coexisting synchronizations and also their statistics may result in a richer understanding of the relations between functional and structural networks of oscillators.This work was partially supported by the Spanish Ministry of Economy and Competitiveness and FEDER (Project No. FIS2015-66503). AEPV acknowledges support from the Swiss National Science Foundation Project NEURECA (CR13I1 138032). J.G.O. also acknowledges support from the the Generalitat de Catalunya (Project No. 2014SGR0947), the ICREA Academia Programme, and from the “María de Maeztu” Programme for Units of Excellence in R&D (Spanish Ministry of Economy and Competitiveness, MDM-2014-0370)

Parkinson’s disease patient-specific neuronal networks carrying the LRRK2 G2019S mutation unveil early functional alterations that predate neurodegeneration

A deeper understanding of early disease mechanisms occurring in Parkinson’s disease (PD) is needed to reveal restorative targets. Here we report that human induced pluripotent stem cell (iPSC)-derived dopaminergic neurons (DAn) obtained from healthy individuals or patients harboring LRRK2 PD-causing mutation can create highly complex networks with evident signs of functional maturation over time. Compared to control neuronal networks, LRRK2 PD patients’ networks displayed an elevated bursting behavior, in the absence of neurodegeneration. By combining functional calcium imaging, biophysical modeling, and DAn-lineage tracing, we found a decrease in DAn neurite density that triggered overall functional alterations in PD neuronal networks. Our data implicate early dysfunction as a prime focus that may contribute to the initiation of downstream degenerative pathways preceding DAn loss in PD, highlighting a potential window of opportunity for pre-symptomatic assessment of chronic degenerative diseases

Multi-Source-Evaluierung eines Ausbildungsprogramms für Medizinstudenten zur Befragung/Aufnahme der klinischen Vorgeschichte anhand standardisierter Patienten

Introduction: Simulations with standardized patients (SP) have long been used for teaching/assessing communication skills. The present study describes and evaluates an experiential training methodology aimed at medical students and based on interviews with standardized simulated patients. The training was focused on developing basic communication skills and taking medical histories. Methods: Longitudinal observational study of a cohort of third-year medical students. Three interviews with SP were carried out and videotaped. These interviews were assessed by the students, the SPs and the professors of the relevant subject areas.Results: 83 students conducted the interviews. The self-evaluations performed by the students showed an improvement between the first and third interviews, as demonstrated by the increase of 6.7% (CI 95%=3.6-10.0%) (p<0.001) in the percentage of detected items. The SPs stated an improvement of 8.5% (CI 95%=2.9-14.1) (p=0.003) from the first to the third interview regarding the percentage of students that showed a level of interest in, and ease with, the patients' concerns. Finally, the teachers found a mean percentage of items identified in the third written clinical history of 61.4% (CI 95%=59.1-63.7) of the total available. Conclusions: This educational program, carried out with standardized simulated patients, showed positive signs of improvement from the first to the third interview, in both the student self-evaluations and the level of interest and ease perceived by the SPs. Additionally, the mean level of information recorded in the written medical histories was considered to be acceptable.Einführung: Simulationen mit standardisierten Patienten (SP) werden seit langem für die Unterricht/Bewertung von Kommunikationsfähigkeiten eingesetzt. Die vorliegende Studie beschreibt und evaluiert eine erfahrungsbasierte Trainingsmethodik, die sich an Medizinstudenten richtet und auf Interviews mit standardisierten simulierten Patienten basiert. Das Training konzentrierte sich auf die Entwicklung grundlegender Kommunikationsfähigkeiten und die Erfassung von Krankengeschichten. Methoden: Längsschnittbeobachtungsstudie an einer Kohorte von Medizinstudenten im dritten Studienjahr. Es wurden drei Interviews mit SP durchgeführt und auf Video aufgenommen. Diese Interviews wurden von den Studierenden, den SPen und den Professoren der entsprechenden Fachbereiche ausgewertet.Ergebnisse: 83 Studenten führten die Interviews durch. Die von den Studierenden durchgeführten Selbsteinschätzungen zeigten eine Verbesserung zwischen dem ersten und dem dritten Interview, wie der Anstieg des Prozentsatzes der entdeckten Items um 6,7% (CI 95%=3,6-10,0%) (p<0,001) zeigt. Die SPen gaben eine Verbesserung von 8,5% (CI 95%=2,9-14,1) (p=0,003) zwischen dem ersten und dem dritten Interview an, was den Prozentsatz der Studierenden betrifft, die ein gewisses Interesse an den Bedenken der Patienten zeigten und mit diesen leicht umgehen konnten. Schließlich fanden die Lehrer einen mittleren Prozentsatz von 61,4% (CI 95%=59,1-63,7) der insgesamt verfügbaren Items, die in der dritten schriftlichen Krankengeschichte identifiziert wurden.Schlussfolgerungen: Dieses Bildungsprogramm, das mit standardisierten simulierten Patienten durchgeführt wurde, zeigte positive Anzeichen einer Verbesserung vom ersten bis zum dritten Interview, sowohl in den Selbsteinschätzungen der Schüler/innen als auch im Grad des Interesses und der Leichtigkeit, die von den SPen wahrgenommen wurde. Zusätzlich wurde das mittlere Informationsniveau, das in den schriftlichen Krankengeschichten aufgezeichnet wurde, als akzeptabel angesehen