Modular architecture facilitates noise-driven control of synchrony in neuronal networks

H.Y., A.H.-I., and S.S. acknowledge MEXT Grant-in-Aid for Transformative Research Areas (B) “Multicellular Neurobiocomputing” (21H05164), JSPS KAKENHI (18H03325, 19H00846, 20H02194, 20K20550, 22H03657, 22K19821, 22KK0177, and 23H03489), JST-PRESTO (JMPJPR18MB), JST-CREST (JPMJCR19K3), and Tohoku University RIEC Cooperative Research Project Program for financial support. F.P.S., V.P., and J.Z. received support from the Max-Planck-Society. F.P.S. acknowledges funding by SMARTSTART, the joint training program in computational neuroscience by the VolkswagenStiftung and the Bernstein Network. F.P.S. and V.P. were funded by the German Research Foundation (Deutsche Forschungsgemeinschaft, DFG), SFB-1528–Cognition of Interaction. V.P. was supported by the DFG under Germany’s Excellence Strategy EXC 2067/1- 390729940. V.B. and A.L. were supported by a Sofja Kovalevskaja Award from the Alexander von Humboldt Foundation, endowed by the Federal Ministry of Education and Research. A.L. is a member of the Machine Learning Cluster of Excellence EXC 2064/1- 39072764. M.A.M. acknowledges the Spanish Ministry and Agencia Estatal de investigación (AEI) through Project of I + D + i (PID2020-113681GB-I00), financed by MICIN/AEI/10.13039/501100011033 and FEDER “A way to make Europe”, and the Consejería de Conocimiento, Investigación Universidad, Junta de Andalucía and European Regional Development Fund (P20-00173) for financial support. J.Z. received financial support from the Joachim Herz Stiftung. J.S. acknowledges Horizon 2020 Future and Emerging Technologies (grant agreement 964877-NEUChiP), Ministerio de Ciencia, Innovación y Universidades (PID2019-108842GB-C21), and Departament de Recerca i Universitats, Generalitat de Catalunya (2017-SGR-1061 and 2021-SGR-00450) for financial support.Supplementary Materials This PDF file includes: Supplementary Text, file:///D:/Modular-architecture-facilitates-.pdfHigh-level information processing in the mammalian cortex requires both segregated processing in specialized circuits and integration across multiple circuits. One possible way to implement these seemingly opposing demands is by flexibly switching between states with different levels of synchrony. However, the mechanisms behind the control of complex synchronization patterns in neuronal networks remain elusive. Here, we use precision neuroengineering to manipulate and stimulate networks of cortical neurons in vitro, in combination with an in silico model of spiking neurons and a mesoscopic model of stochastically coupled modules to show that (i) a modular architecture enhances the sensitivity of the network to noise delivered as external asynchronous stimulation and that (ii) the persistent depletion of synaptic resources in stimulated neurons is the underlying mechanism for this effect. Together, our results demonstrate that the inherent dynamical state in structured networks of excitable units is determined by both its modular architecture and the properties of the external inputs.D+i: P20-00173, PID2020-113681GB-I00Innovación y Universidades PID2019-108842GB-C21Horizon2020 Future and Emerging Technologies 964877-NEUChiPMinisterio de Ciencia, Innovación y Universidades (PID2019-108842GB-C21)Departament de Recerca i Universitats, Generalitat de Catalunya (2017-SGR-1061, 2021-SGR-00450)MICIN/AEI/10.13039/501100011033FEDER “A way to make Europe”Junta de AndalucíaEuropean Regional Development Fun

Excitatory-inhibitory branching process: A parsimonious view of cortical asynchronous states, excitability, and criticality

We acknowledge the Spanish Ministry and Agencia Estatal de investigación (AEI) through Project of I + D+i Ref. PID2020-113681GB-I00, financed by MICIN/AEI/10.13039/501100011033 and FEDER “A way to make Europe,” as well as the Consejería de Conocimiento, Investigación Universidad, Junta de Andalucía and European Regional Development Fund, Project references A-FQM-175-UGR18 and P20-00173, for financial support. R.C.L. acknowledges funding from the Spanish Ministry and AEI, Grant No. FPU19/03887. This work was partially supported by a Sofja Kovalevskaja Award from the Alexander von Humboldt Foundation, endowed by the German Federal Ministry of Education and Research (V.B.). We also thank H. C. Piuvezam, J. Pretel, G. B. Morales, P. Moretti, O. Vinogradov, and E. Giannakakis for valuable discussions.The branching process is the minimal model for propagation dynamics, avalanches, and criticality, broadly used in neuroscience. A simple extension of it, adding inhibitory nodes, induces a much-richer phenomenology, including an intermediate phase, between quiescence and saturation, that exhibits the key features of “asynchronous states” in cortical networks. Remarkably, in the inhibition-dominated case, it exhibits an extremely rich phase diagram that captures a wealth of nontrivial features of spontaneous brain activity, such as collective excitability, hysteresis, tilted avalanche shapes, and partial synchronization, allowing us to rationalize striking empirical findings within a common and parsimonious framework.Alexander von Humboldt-StiftungBundesministerium für Bildung und ForschungFEDEREuropean Regional Development Fund A-FQM-175-UGR18, FPU19/03887, P20-00173 ERDFAgencia Estatal de Investigación MICIN/AEI/10.13039/501100011033, PID2020-113681GB-I0

A topological classification of plane polynomial systems having a globally attracting singular point

In this paper, plane polynomial systems having a singular point attracting all orbits in positive time are classified up to topological equivalence. This is done by assigning a combinatorial invariant to the system (a so-called "feasible set" consisting of finitely many vectors with components in the set $\{n/3: n=0,1,2,\ldots\}$), so that two such systems are equivalent if and only if (after appropriately fixing an orientation in $\mathbb{R}^2$ and a heteroclinic separatrix) they have the same feasible set. In fact, this classification is achieved in the more general setting of continuous flows having finitely many separatrices. Polynomial representatives for each equivalence class are found, although in a non-constructive way. Since, to the best of our knowledge, the literature does not provide any concrete polynomial system having a non-trivial globally attracting singular point, an explicit example is given as well.Comment: 30 pages, 9 figure

Feedback Mechanisms for Self-Organization to the Edge of a Phase Transition

Scale-free outbursts of activity are commonly observed in physical, geological, and biological systems. The idea of self-organized criticality (SOC), introduced back in 1987 by Bak, Tang, and Wiesenfeld suggests that, under certain circumstances, natural systems can seemingly self-tune to a critical state with its concomitant power-laws and scaling. Theoretical progress allowed for a rationalization of how SOC works by relating its critical properties to those of a standard non-equilibrium second-order phase transition that separates an active state in which dynamical activity reverberates indefinitely, from an absorbing or quiescent state where activity eventually ceases. The basic mechanism underlying SOC is the alternation of a slow driving process and fast dynamics with dissipation, which generates a feedback loop that tunes the system to the critical point of an absorbing-active continuous phase transition. Here, we briefly review these ideas as well as a recent closely-related concept: self-organized bistability (SOB). In SOB, the very same type of feedback operates in a system characterized by a discontinuous phase transition, which has no critical point but instead presents bistability between active and quiescent states. SOB also leads to scale-invariant avalanches of activity but, in this case, with a different type of scaling and coexisting with anomalously large outbursts. Moreover, SOB explains experiments with real sandpiles more closely than SOC. We review similarities and differences between SOC and SOB by presenting and analyzing them under a common theoretical framework, covering recent results as well as possible future developments. We also discuss other related concepts for "imperfect" self-organization such as "self-organized quasi-criticality" and "self-organized collective oscillations," of relevance in e.g., neuroscience, with the aim of providing an overview of feedback mechanisms for self-organization to the edge of a phase transition.We acknowledge the Spanish Ministry and Agencia Estatal de investigacion (AEI) through grant FIS2017-84256-P European Regional Development Fund (ERDF), as well as the Consejeria de Conocimiento, Investigacion y Universidad, Junta de Andalucia and ERDF, A-FQM -175-UGR18 and SOMM17/6105/UGR and for financial support. We also thank Cariparma for their support through the TEACH IN PARMA project

Adición de agregado calcáreo y Conchuela en dietas de pollos de carne y su efecto en la producción

El objetivo del presente trabajo fue evaluar la influencia de la adición de dos fuentes de calcio sobre los parámetros productivos de pollos de carne de la línea Cobb 500. Se utilizó un Diseño Completamente al Azar y la prueba Tukey al 5%, se evaluaron 80 pollos, con dos tratamientos y cuatro repeticiones, los tratamientos fueron: tratamiento uno (T1) agregado calcáreo, fuente inorgánica y el tratamiento 2 (T2) conchuela, fuente orgánica, ambas con un tamaño de partícula de 180 μ (micras). Los resultados de la evaluación a los 21 días, fueron 820,38 y 843,5 g (gramos) para el Peso y 796,00 y 798,3 g para la ganancia de peso. El contenido de ceniza en la tibia de los pollos fue de 57,63 y 58,74 % y, 42,24 y 40,31 % para el contenido de calcio. En las variables indicadas, no se encontraron diferencias estadísticas significativas entre tratamientos (P < 0,05). Pero en el consumo y conversión alimenticia se hallaron diferencias estadísticas significativas (P < 0,05), obteniendo 1113,10 y 11081,90 g para el consumo de alimento y, 1,40 y 1,36 para la conversión alimenticia. En conclusión, ambas fuentes de calcio pueden ser utilizadas en la alimentación de pollos de carne, sin embargo, se debe evaluar el mérito económico del alimento

Jensen’s force and the statistical mechanics of cortical asynchronous states

Cortical networks are shaped by the combined action of excitatory and inhibitory interactions. Among other important functions, inhibition solves the problem of the all-or-none type of response that comes about in purely excitatory networks, allowing the network to operate in regimes of moderate or low activity, between quiescent and saturated regimes. Here, we elucidate a noise-induced effect that we call “Jensen’s force” –stemming from the combined effect of excitation/inhibition balance and network sparsity– which is responsible for generating a phase of self-sustained low activity in excitationinhibition networks. The uncovered phase reproduces the main empirically-observed features of cortical networks in the so-called asynchronous state, characterized by low, un-correlated and highly-irregular activity. The parsimonious model analyzed here allows us to resolve a number of long-standing issues, such as proving that activity can be self-sustained even in the complete absence of external stimuli or driving. The simplicity of our approach allows for a deep understanding of asynchronous states and of the phase transitions to other standard phases it exhibits, opening the door to reconcile, asynchronousstate and critical-state hypotheses, putting them within a unified framework. We argue that Jensen’s forces are measurable experimentally and might be relevant in contexts beyond neuroscience.The study is supported by Fondazione Cariparma, under TeachInParma Project. MAM thanks the Spanish Ministry of Science and the Agencia Española de Investigación (AEI) for financial support under grant FIS2017-84256-P (European Regional Development Fund (ERDF)) as well as the Consejera de Conocimiento, Investigación y Universidad, Junta de Andaluca and European Regional Development Fund (ERDF), ref. SOMM17/6105/UGR. V.B. and R.B. acknowledge funding from the INFN BIOPHYS projec

Planeamiento estratégico del sector artesanía de la región Ayacucho

La presente tesis propone un plan estratégico para desarrollar el sector artesanía en la región Ayacucho hacia el año 2020. Se proyecta al ámbito nacional e internacional por la riqueza cultural y religiosa, importancia histórica y valor artesanal que ha servido para alcanzar su denominación como “Capital de la artesanía peruana”. La actividad artesanal durante la última década ha logrado el incremento de su valor comercial con la contribución de organizaciones de promoción públicas y privadas. Ha conseguido adecuarse a tendencias y exigencias de mercados internacionales a través de participación en ferias, capacitaciones y del incremento de los pedidos de los clientes. Esto, sumado a la creación de nuevas empresas y acreditación de nuevos artesanos con falta de visión estratégica y una reglamentación artesanal, motivan el desarrollo la competitividad a nivel regional. Del análisis de fuerzas, entre las oportunidades identificadas están la firma de convenios y TLC que coadyuvan al acceso a nuevos mercados, la existencia de organizaciones promotoras de exportaciones, el crecimiento de la economía peruana y existencia de escenarios para ofrecer productos artesanales; y entre las fortalezas, la preservación de costumbres y tradiciones ancestrales, el prestigio artesanal reconocido, la elevada creatividad y habilidad, la materia prima disponible, la diversidad de líneas artesanales y la mano de obra barata. Por estas condiciones se propone una intensa promoción de la marca ‘Artesanía Ayacucho’, que se puede consolidar a través de alianzas estratégicas con organizaciones de promoción empresarial, especialización de la mano de obra y diseño de artesanías para cada mercado, así como con la integración hacia atrás con proveedores de materias primas y la diversificación concéntrica de principales artesanías. Estas circunstancias contribuirán al desarrollo competitivo del sector mejorando la comercialización de productos, e incrementarán los ingresos y la mejora de las condiciones de la cadena. Las oportunidades son diversas y las expectativas de crecimiento, mayores. Se plantea el compromiso de la Mesa Técnica de Artesanía que promueva alianzas estratégicas con organizaciones de promoción para garantizar su sostenibilidad.This paper proposes a strategic plan to develop the craft industry in the Ayacucho region by 2020. It projects national and international areas because of the cultural and religious wealth, historical and traditional values that have served to reach their designation as Capital of Peruvian Handicrafts. The craft over the last decade has increased its market value, the contribution of public and private institutions have helped to promote it. Those institutions have managed their strategies to adapt to trends and demands of international markets through participation in trade fairs, training and increase clients’ orders. This fact,, coupled with the creation of new businesses and accreditation of new artisans lack of strategic vision and craft regulations encourage the development of competitiveness at regional level. Analysis of forces, including the opportunities identified as signing agreements and FTAs that contribute to access to new markets, existence of organizations that promote exports, growth of the Peruvian economy and the existence of scenarios to provide stalls, and the strengths and preservation customs and traditions, craft recognized prestige, high creativity and skill, raw material available, a variety of craft lines and cheap labor, we propose a strong branding Craft Ayacucho, building strategic alliances with business development, labor specialization and craft design for each market, integrate backwards with suppliers of raw materials and concentric diversification of major crafts. These contribute to the competitive development of the sector by improving the marketing of products, increase revenue and improve the conditions of the chain. The opportunities are diverse and growth expectations, higher. This raises the commitment of the Technical Committee to promote Craft strategic alliances with advocacy organizations to ensure sustainability.Tesi