How models of canonical microcircuits implement cognitive functions

Major cognitive functions such as language, memory, and decision-making are thought to rely on distributed networks of a large number of fundamental neural elements, called canonical microcircuits. A mechanistic understanding of the interaction of these canonical microcircuits promises a better comprehension of cognitive functions as well as their potential disorders and corresponding treatment techniques. This thesis establishes a generative modeling framework that rests on canonical microcircuits and employs it to investigate composite mechanisms of cognitive functions. A generic, biologically plausible neural mass model was derived to parsimoniously represent conceivable architectures of canonical microcircuits. Time domain simulations and bifurcation and stability analyses were used to evaluate the model’s capability for basic information processing operations in response to transient stimulations, namely signal flow gating and working memory. Analysis shows that these basic operations rest upon the bistable activity of a neural population and the selectivity for the stimulus’ intensity and temporal consistency and transiency. In the model’s state space, this selectivity is marked by the distance of the system’s working point to a saddle-node bifurcation and the existence of a Hopf separatrix. The local network balance, in regard of synaptic gains, is shown to modify the model’s state space and thus its operational repertoire. Among the investigated architectures, only a three-population model that separates input-receiving and output-emitting excitatory populations exhibits the necessary state space characteristics. It is thus specified as minimal canonical microcircuit. In this three-population model, facilitative feedback information modifies the retention of sensory feedforward information. Consequently, meta-circuits of two hierarchically interacting minimal canonical microcircuits feature a temporal processing history that enables state-dependent processing operations. The relevance of these composite operations is demonstrated for the neural operations of priming and structure-building. Structure-building, that is the sequential and selective activation of neural circuits, is identified as an essential mechanism in a neural network for syntax parsing. This insight into cognitive processing proves the modeling framework’s potential in neurocognitive research. This thesis substantiates the connectionist notion that higher processing operations emerge from the combination of minimal processing elements and advances the understanding how cognitive functions are implemented in the neocortical matter of the brain.Kognitive Fähigkeiten wie Sprache, Gedächtnis und Entscheidungsfindung resultieren vermutlich aus der Interaktion vieler fundamentaler neuronaler Elemente, sogenannter kanonischer Schaltkreise. Eine vertiefte Einsicht in das Zusammenwirken dieser kanonischen Schaltkreise verspricht ein besseres Verständnis kognitiver Fähigkeiten, möglicher Funktionsstörungen und Therapieansätze. Die vorliegende Dissertation untersucht ein generatives Modell kanonischer Schaltkreise und erforscht mit dessen Hilfe die Zusammensetzung kognitiver Fähigkeiten aus konstitutiven Mechanismen neuronaler Interaktion. Es wurde ein biologisch-plausibles neuronales Massenmodell erstellt, das mögliche Architekturen kanonischer Schaltkreise generisch berücksichtigt. Anhand von Simulationen sowie Bifurkations- und Stabilitätsanalysen wurde untersucht, inwiefern das Modell grundlegende Operationen der Informationsverarbeitung, nämlich Selektion und temporäre Speicherung einer transienten Stimulation, unterstützt. Die Untersuchung zeigt, dass eine bistabile Aktivität einer neuronalen Population und die Beurteilung der Salienz des Signals den grundlegenden Operationen zugrunde liegen. Die Beurteilung der Salienz beruht dabei hinsichtlich der Signalstärke auf dem Abstand des Arbeitspunktes zu einer Sattel-Knoten-Bifurkation und hinsichtlich der Signalkonsistenz und-–vergänglichkeit auf einer Hopf-Separatrix im Zustandsraum des Systems. Die Netzwerkbalance modifiziert diesen Zustandsraum und damit die Funktionsfähigkeit des Modells. Nur ein Drei-Populationenmodell mit getrennten erregenden Populationen für Signalempfang und -emission weist die notwendigen Bedingungen im Zustandsraum auf und genügt der Definition eines minimalen kanonischen Schaltkreises. In diesem Drei-Populationenmodell erleichtert ein Feedbacksignal die Speicherfähigkeit für sensorische Feedforwardsignale. Dementsprechend weisen hierarchisch interagierende minimale kanonische Schaltkreise ein zeitliches Verarbeitungsgedächtnis auf, das zustandsabhängige Verarbeitungsoperationen erlaubt. Die Bedeutung dieser konstitutiven Operationen wird für die neuronalen Operationen Priming und Strukturbildung verdeutlicht. Letztere wurde als wichtiger Mechanismus in einem Netzwerk zur Syntaxanalyse identifiziert und belegt das Potential des Modellansatzes für die neurokognitive Forschung. Diese Dissertation konkretisiert die konnektionistische Ansicht höhere Verarbeitungsoperationen als Ergebnis der Kombination minimaler Verarbeitungselemente zu verstehen und befördert das Verständnis für die Frage wie kognitive Fähigkeiten im Nervengewebe des Gehirns implementiert sind

Quantifying uncertainties of climate signals in chemistry climate models related to the 11-year solar cycle – Part 1: Annual mean response in heating rates, temperature, and ozone

Variations in the solar spectral irradiance (SSI) with the 11-year sunspot cycle have been shown to have a significant impact on temperatures and the mixing ratios of atmospheric constituents in the stratosphere and mesosphere. Uncertainties in modelling the effects of SSI variations arise from uncertainties in the empirical models reconstructing the prescribed SSI data set as well as from uncertainties in the chemistry–climate model (CCM) formulation. In this study CCM simulations with the ECHAM/MESSy Atmospheric Chemistry (EMAC) model and the Community Earth System Model 1 (CESM1)–Whole Atmosphere Chemistry Climate Model (WACCM) have been performed to quantify the uncertainties of the solar responses in chemistry and dynamics that are due to the usage of five different SSI data sets or the two CCMs. We apply a two-way analysis of variance (ANOVA) to separate the influence of the SSI data sets and the CCMs on the variability of the solar response in shortwave heating rates, temperature, and ozone. The solar response is derived from climatological differences of time slice simulations prescribing SSI for the solar maximum in 1989 and near the solar minimum in 1994. The SSI values for the solar maximum of each SSI data set are created by adding the SSI differences between November 1994 and November 1989 to a common SSI reference spectrum for near-solar-minimum conditions based on ATLAS-3 (Atmospheric Laboratory of Applications and Science-3). The ANOVA identifies the SSI data set with the strongest influence on the variability of the solar response in shortwave heating rates in the upper mesosphere and in the upper stratosphere–lower mesosphere. The strongest influence on the variability of the solar response in ozone and temperature is identified in the upper stratosphere–lower mesosphere. However, in the region of the largest ozone mixing ratio, in the stratosphere from 50 to 10 hPa, the SSI data sets do not contribute much to the variability of the solar response when the Spectral And Total Irradiance REconstructions-T (SATIRE-T) SSI data set is omitted. The largest influence of the CCMs on variability of the solar responses can be identified in the upper mesosphere. The solar response in the lower stratosphere also depends on the CCM used, especially in the tropics and northern hemispheric subtropics and mid-latitudes, where the model dynamics modulate the solar responses. Apart from the upper mesosphere, there are also regions where the largest fraction of the variability of the solar response is explained by randomness, especially for the solar response in temperature

Microfabrication and surface functionalization of soda lime glass through direct laser interference patterning

All-purpose glasses are common in many established and emerging industries, such as microelectronics, photovoltaics, optical components, and biomedical devices due to their outstanding combination of mechanical, optical, thermal, and chemical properties. Surface functionalization through nano/micropatterning can further enhance glasses’ surface properties, expanding their applicability into new fields. Although laser structuring methods have been successfully employed on many absorbing materials, the processability of transparent materials with visible laser radiation has not been intensively studied, especially for producing structures smaller than 10 µm. Here, interference-based optical setups are used to directly pattern soda lime substrates through non-lineal absorption with ps-pulsed laser radiation in the visible spectrum. Line-and dot-like patterns are fabricated with spatial periods between 2.3 and 9.0 µm and aspect ratios up to 0.29. Furthermore, laserinduced periodic surface structures (LIPSS) with a feature size of approximately 300 nm are visible within these microstructures. The textured surfaces show significantly modified properties. Namely, the treated surfaces have an increased hydrophilic behavior, even reaching a super-hydrophilic state for some cases. In addition, the micropatterns act as relief diffraction gratings, which split incident light into diffraction modes. The process parameters were optimized to produce high-quality textures with super-hydrophilic properties and diffraction efficiencies above 30%.Fil: Soldera, Marcos Maximiliano. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigación y Desarrollo en Ingeniería de Procesos, Biotecnología y Energías Alternativas. Universidad Nacional del Comahue. Instituto de Investigación y Desarrollo en Ingeniería de Procesos, Biotecnología y Energías Alternativas; ArgentinaFil: Alamri, Sabri. Fraunhofer Institute For Material And Beam Technology Iws; AlemaniaFil: Sürmann, Paul Alexander. Fraunhofer Institute For Material And Beam Technology Iws; AlemaniaFil: Kunze, Tim. Fraunhofer Institute For Material And Beam Technology Iws; AlemaniaFil: Lasagni, Andrés Fabián. Technische Universität Dresden; Alemani

TRANSIT Deliverable 2.3. Cross-cutting theme: Social Learning

Theme [ssh.2013.3.2-1][Social Innovation- Empowering People, changing societies]Project Full Title: “Transformative Social Innovation Theory project”[Abstract] The object of the present deliverable is the integration of the main outcomes of empirical research and integration activities developed within the TRANSIT project on the cross-cutting theme of “social learning” as well as the distilling of main insights for the development of “practical briefs and tools”. Deliverable 2.3 reports on the outcomes of these activities, and consists of the following sections: 1. Working paper: " The role of social learning in transformative social innovations" 2. Synthesis of the third integration workshop: Motivations, relations and transformations. The role of social learning in individual and collective agency for social innovation 3. Social Learning with PEERs: Practitioner Engagement for Empowering Reflections 4. Insights on Social Learning for Transformative Social Innovation Practice (input for practice brief and practice tool.This project has received funding from the European Union’s Seventh Framework Programme for research, technological development and demonstration under grant agreement no 61316

Unique, Persistent, Resolvable: Identifiers as the foundation of FAIR

The FAIR Principles describe characteristics intended to support access to and reuse of digital artifacts in the scientific research ecosystem. Persistent, globally unique identifiers, resolvable on the Web, and associated with a set of additional descriptive metadata, are foundational to FAIR data. Here we describe some basic principles and exemplars for their design, use and orchestration with other system elements to achieve FAIRness for digital research objects

Label-free detection of C-Reactive protein using bioresponsive hydrogel-based surface relief diffraction gratings

[EN] Responsive hydrogel-based surface relief gratings have demonstrated great performances as transducers in optical sensing. However, novel and smart designs of hydrogels are needed for the appropriate detection of analytes and biomolecules since the existing materials are very limited to specific molecules. In this work, a biosensing system based on surface relief gratings made of bioresponsive hydrogels has been developed. In particular, the hydrogel contains phosphocholine moieties to specifically recognize C-Reactive protein (CRP). The CRP-Sensing hydrogel capacity to selectively detect CRP was fully demonstrated. Using Direct Laser Interference Patterning, micro-gratings were created on CRP-Sensing hydrogel substrates and applied for the label-free sensing of CRP using a simple laser-based homemade optical setup. Limits of detection (LOD) and quantification (LOQ) in human serum dilutions of 1.07 and 8.92 mg L-1, respectively, were reached. These results demonstrate that the biosensing system allows the selective label-free detection of CRP within concentration ranges around those related to risks of cardiovascular diseases and sepsis. Besides, amplification strategies have been carried out improving the sensitivity, widening the linear range, and reaching better LOD and LOQ (0.30 mg L-1 and 4.36 mg L-1). Finally, all the approaches were tested for the quantification of CRP in certified human serum with recoveries of around 100%.This work was financially supported by the E.U. FEDER, the Spanish Ministry of Economy and Competitiveness MINECO (BiHolog-CTQ2016- 75749-R and AdBiHol-PID2019-110713RB-I00) and Generalitat Valenciana (PROMETEO/2020/094). M. I. Lucío acknowledges MINECO for her Juan de la Cierva Formacion and Incorporacion grants (FJCI-2016-29593, IJC 2018-035355-I). The authors acknowledge the assistance and advice of the Electron Microscopy Service of the Universitat Politècnica de València.Lucío, MI.; Hernández-Montoto, A.; Fernández-Sánchez, ME.; Alamri, S.; Kunze, T.; Bañuls Polo, M.; Maquieira Catala, Á. (2021). Label-free detection of C-Reactive protein using bioresponsive hydrogel-based surface relief diffraction gratings. Biosensors and Bioelectronics. 193:1-10. https://doi.org/10.1016/j.bios.2021.11356111019

Convergence Analysis of an Iterative Targeting Method for Keyhole Robotic Surgery

In surgical procedures, robots can accurately position and orient surgical instruments. Intraoperatively, external sensors can localize the instrument and compute the targeting movement of the robot, based on the transformation between the coordinate frame of the robot and the sensor. This paper addresses the assessment of the robustness of an iterative targeting algorithm in perturbed conditions. Numerical simulations and experiments (with a robot with seven degrees of freedom and an optical tracking system) were performed for computing the maximum error of the rotational part of the calibration matrix, which allows for convergence, as well as the number of required iterations. The algorithm converges up to 50 degrees of error within a large working space. The study confirms the clinical relevance of the method because it can be applied on commercially available robots without modifying the internal controller, thus improving the targeting accuracy and meeting surgical accuracy requirements

Transitions towards new economies? A transformative social innovation perspective

There are numerous social innovation networks and initiatives worldwide with the ambition to contribute to transformative change towards more sustainable, resilient and just societies. Many of these have a specific vision on the economy and relate to alternative visions of a ‘New Economy’. This paper highlights four prominent strands of new economy thinking in state-of-the-art discussions: degrowth, collaborative economy, solidarity economy, and social entrepreneurship. Taking a perspective of transformative social innovation, the paper draws on case studies of 12 social innovation initiatives to analyse how these relate to new economies and to transitions toward new economic arrangements. The 12 cases are analysed in terms of a) how they relate to narratives of change on new economies, b) how they renew social relations, and c) how their new economy arrangements hold potential to challenge established institutional constellations in the existing economy