175 research outputs found
In Favour of Machines (But Not Forgetting the Workers): Some Considerations on the Fourth Industrial Revolution
No full textThis chapter aims to guide the reader in the analysis of some of the main themes proposed by the debate related to the Fourth Industrial Revolution (4IR). First, we discuss the impact of the 4IR on employment by reviewing the results of the relevant economic literature, drawing some suggestions for future research. Second, we review some of the policies developed by governments to support the digital revolution. We argue that while Industry 4.0-type policies are common to all advanced countries, policies in favour of digital technologies in the service sector are more fragmented, difficult to implement, and face a stronger resistance from workers. We finish the paper with a discussion of the main policy issues related to the workers and the labour market, with a focus on robot tax, shared robot ownership, and universal basic income. We conclude by emphasizing that while policies in favour of machines are widespread and supported by wide social consensus, effective polices in favour of workers are much weaker and still unable to mitigate the negative effects of the digital revolution
Action potential processing in a detailed Purkinje cell model reveals a critical role for axonal compartmentalization
No full textThe Purkinje cell (PC) is among the most complex neurons in the brain and plays a critical role for cerebellar functioning. PCs operate as fast pacemakers modulated by synaptic inputs but can switch from simple spikes to complex bursts and, in some conditions, show bistability. In contrast to original works emphasizing dendritic Ca-dependent mechanisms, recent experiments have supported a primary role for axonal Na-dependent processing, which could effectively regulate spike generation and transmission to deep cerebellar nuclei (DCN). In order to account for the numerous ionic mechanisms involved (at present including Nav1.6, Cav2.1, Cav3.1, Cav3.2, Cav3.3, Kv1.1, Kv1.5, Kv3.3, Kv3.4, Kv4.3, KCa1.1, KCa2.2, KCa3.1, Kir2.x, HCN1), we have elaborated a multicompartmental model incorporating available knowledge on localization and gating of PC ionic channels. The axon, including initial segment (AIS) and Ranvier nodes (RNs), proved critical to obtain appropriate pacemaking and firing frequency modulation. Simple spikes initiated in the AIS and protracted discharges were stabilized in the soma through Na-dependent mechanisms, while somato-dendritic Ca channels contributed to sustain pacemaking and to generate complex bursting at high discharge regimes. Bistability occurred only following Na and Ca channel down-regulation. In addition, specific properties in RNs K currents were required to limit spike transmission frequency along the axon. The model showed how organized electroresponsive functions could emerge from the molecular complexity of PCs and showed that the axon is fundamental to complement ionic channel compartmentalization enabling action potential processing and transmission of specific spike patterns to DCN
Ensemble neuronal responses in a large-scale realistic model of the cerebellar cortex
No full textRealistic simulation of central networks remains a challenge due to the complexity of internal connectivity and cellular mechanisms involved. We have recently built a realistic model of the cerebellar granular layer..
A hybrid model for the computationally-efficient simulation of the cerebellar granular layer
No full textThe aim of the present paper is to efficiently describe the membrane potential dynamics of neural populations formed by species having a high density difference in specific brain areas. We propose a hybrid model whose main ingredients are a conductance-based model (ODE system) and its continuous counterpart (PDE system) obtained through a limit process in which the number of neurons confined in a bounded region of the brain tissue is sent to infinity. Specifically, in the discrete model, each cell is described by a set of time-dependent variables, whereas in the continuum model, cells are grouped into populations that are described by a set of continuous variables.Communications between populations, which translate into interactions among the discrete and the continuous models, are the essence of the hybrid model we present here. The cerebellum and cerebellum-like structures show in their granular layer a large difference in the relative density of neuronal species making them a natural testing ground for our hybrid model. By reconstructing the ensemble activity of the cerebellar granular layer network and by comparing our results to a more realistic computational network, we demonstrate that our description of the network activity, even though it is not biophysically detailed, is still capable of reproducing salient features of neural network dynamics. Our modeling approach yields a significant computational cost reduction by increasing the simulation speed at least times. The hybrid model reproduces interesting dynamics such as local microcircuit synchronization, traveling waves, center-surround and time-windowing
High-Voltage-Activated Calcium Channels
No full textThe annual Computational Neuroscience Meeting (CNS) began in 1990 as a small workshop called Analysis and Modeling of Neural Systems. The goal of the workshop was to explore the boundary between neuroscience and computation. Riding on the success of several seminal papers, physicists had made "Neural Networks" fashionable, and soon the quantitative methods used in these abstract model networks started permeating the methods and ideas of experimental neuroscientists. Although experimental neurophysiological approaches provided many advances, it became increasingly evident that mathematical and computational techniques would be required to achieve a comprehensive and quantitative understanding of neural system function. “Computational Neuroscience” emerged to complement experimental neurophysiology. In 2002, the non-profit organization, Organization for Computational Neuroscience (OCNS) was formed. OCNS has now become the first professional society serving the global computational neuroscience community. OCNS as a society lives at the interface where experimental neuroscience meets theoretical, statistical and computer-simulation analyses, with the hope of turning large collections of experimental results into a principled understanding of nervous systems. It also supports the development of new engineering, computational and informatics techniques for data collection, analyses and management
Fast-reset of pacemaking and theta-frequency resonance patterns in cerebellar golgi cells: Simulations of their impact <I>in vivo</I>
No full textThe Golgi cells are inhibitory interneurons of the cerebellar granular layer, which respond to afferent stimulation in vivo with a burst-pause sequence interrupting their irregular background low-frequency firing (Vos et al., 1999a. Eur. J. Neurosci. 11, 2621–2634). However, Golgi cells in vitro are regular pacemakers (Forti et al., 2006. J. Physiol. 574, 711–729), raising the question how their ionic mechanisms could impact on responses during physiological activity. Using patch-clamp recordings in cerebellar slices we show that the pacemaker cycle can be suddenly reset by spikes, making the cell highly sensitive to input variations. Moreover, the neuron resonates around the pacemaker frequency, making it specifically sensitive to patterned stimulation in the theta-frequency band. Computational analysis based on a model developed to reproduce Golgi cell pacemaking (Solinas et al., 2008 Front. Neurosci., 1:2) predicted that phase-reset required spike-triggered activation of SK channels and that resonance was sustained by a slow voltage-dependent potassium current and amplified by a persistent sodium current. Adding balanced synaptic noise to mimic the irregular discharge observed in vivo, we found that pacemaking converts into spontaneous irregular discharge, that phase-reset plays an important role in generating the burst-pause pattern evoked by sensory stimulation, and that repetitive stimulation at theta-frequency enhances the time-precision of spike coding in the burst. These results suggest that Golgi cell intrinsic properties exert a profound impact on time-dependent signal processing in the cerebellar granular layer
Rivolte mancate. Sulle correlazioni tra emozioni e spregio in Axel Honneth e Barrington Moore Jr.
No full textIl saggio è dedicato all’analisi delle correlazioni tra dimensione normativa e reazioni emotive, e più in particolare tra senso dell’ingiustizia e collera morale proposte da Barring- ton Moore e Axel Honneth. Si parte dalla teoria di Moore ripresa da Honneth, per poi con- centrare l’attenzione sulla teoria dello spregio (Missachtung) delineata da Honneth in Lotta per il riconoscimento. Tale teoria viene quindi problematizzata, soprattutto attraverso una analisi delle reazioni emotive di taglio regressivo che seguono a determinate esperienze di ingiustizia.
Lacking riots. On the connections between emotions and disrespect in Axel Honneth and
Barrington Moore Jr.
The paper concerns the analysis of the connections between normative dimension and emotional reactions, and particularly between the sense of injustice and the moral anger out- lined by Barrington Moore and Axel Honneth. The Author starts by discussing the theory of Moore regained by Axel Honneth, then he offers an analysis of the theory of disrespect (Missachtung) outlined by Honneth in Struggle for Recognition. The Author criticizes this theory, particularly he outlines an analysis of the regressive emotional reactions activated by specific experiences of injustice
Computational reconstruction of pacemaking and intrinsic electroresponsiveness in cerebellar golgi cells
No full textThe Golgi cells have been recently shown to beat regularly in vitro (Forti et al., 2006. J. Physiol. 574, 711-729). Four main currents were shown to be involved, namely a persistent sodium current (INa-p), an h current (Ih), an SK-type calcium-dependent potassium current (IK-AHP), and a slow M-like potassium current (IK-slow). These ionic currents could take part, together with others, also to different aspects of neuronal excitability like responses to depolarizing and hyperpolarizing current injection. However, the ionic mechanisms and their interactions remained largely hypothetical. In this work, we have investigated the mechanisms of Golgi cell excitability by developing a computational model. The model predicts that pacemaking is sustained by subthreshold oscillations tightly coupled to spikes. INa-p and IK-slow emerged as the critical determinants of oscillations. Ih also played a role by setting the oscillatory mechanism into the appropriate membrane potential range. IK-AHP, though taking part to the oscillation, appeared primarily involved in regulating the ISI following spikes. The combination with other currents, in particular a resurgent sodium current (INa-r) and an A-current (IK-A), allowed a precise regulation of response frequency and delay. These results provide a coherent reconstruction of the ionic mechanisms determining Golgi cell intrinsic electroresponsiveness and suggests important implications for cerebellar signal processing, which will be fully developed in a companion paper (Solinas et al., 2008. Front. Neurosci. 1:4)
Elementi per una teoria critica delle regressioni
No full textThe essay aims to offer a critical theory of psychosocial processes of regressive and depressive type. The Author starts by discussing the determining influence attributed to social suffering in the framework of the moral grammar of social struggle outlined by Axel Honneth, then he offers an analysis of the regressive reactions activate by disrespect experiences. The Author discusses some important points of Walter Benjamin’s philosophy of history, in particularly Benjamin’s critique of traditional concept of progress, and the determining role attributed to suffering; points that are translated and moved in the framework of the analysis of regressive processes. Lastly, the Author shows how a critical theory that aims to reactivate the emancipatory potential immanent in the social suffering today frustrated may find an incisive and productive approach in a critical analysis of regressions. Il saggio mira ad offrire una teoria critica dei processi psicosociali di taglio regressivo e depressivo. L’autore muove dalla centralità attribuita alla sofferenza sociale nel quadro della grammatica morale delle lotte sociali delineato da Axel Honneth, concentrandosi poi sulle reazioni di carattere regressivo indotte dalle esperienze di spregio. Segue la ripresa di alcuni punti fondamentali della filosofia della storia di Walter Benjamin, in particolare della sua critica alla concezione tradizionale di progresso, e la sua peculiare valorizzazione della sofferenza; spunti tradotti e traslati nell’ambito dell’analisi dei processi regressivi. Infine, l’autore mostra come una teoria critica che voglia riattivare i potenziali emancipatori immanenti alla sofferenza sociale oggi frustrati possa trovare un approccio incisivo e fecondo in una analisi critica delle regressioni
Democratic Ethos, Imagination and Emotions
No full textThe paper is focused on Alessandro Ferrara’s attempt to overcome the limits of proceduralism through a reconsideration of some normative sources able to mobilize and to motivate people on the double level of ethos and of political imagination. In particular, on the subject of the thematization of imagination as a political force able to mobilize the people, the author tries to show that a deeper consideration of the emotional dimension might even prove
to be useful for the basic aims pursued by Ferrara on the methodological level. The same can be said for the thematization of the democratic ethos proposed by Ferrara: this ethos is in fact first of all based on specific “passions”, and represents in general the “affective basis of a democracy”. The author attempts then to test whether some possible lines of research into a theoretical development of these topics related to the emotions would be productive
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