53 research outputs found

    FOLDER3D: A graphical file management system supporting visualisation of file relationships

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    The desktop metaphor with its hierarchical structure of folders is the basis of almost all graphical file management systems. Despite this popularity, these systems suffer from several problems, including the restrictiveness of the single inheritance structure of hierarchical file management. Although various alternative systems have been proposed, none of these have gained popularity. We argue that the reason for this failure is that these systems have generally proposed complete alternatives to the hierarchical system, thus ignoring many of its positive aspects. In this paper we describe a 3D graphical file management which complements conventional 2D hierarchical folder structures by allowing visualisation of alternative file relationships

    NeuroML: A Language for Describing Data Driven Models of Neurons and Networks with a High Degree of Biological Detail

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    Biologically detailed single neuron and network models are important for understanding how ion channels, synapses and anatomical connectivity underlie the complex electrical behavior of the brain. While neuronal simulators such as NEURON, GENESIS, MOOSE, NEST, and PSICS facilitate the development of these data-driven neuronal models, the specialized languages they employ are generally not interoperable, limiting model accessibility and preventing reuse of model components and cross-simulator validation. To overcome these problems we have used an Open Source software approach to develop NeuroML, a neuronal model description language based on XML (Extensible Markup Language). This enables these detailed models and their components to be defined in a standalone form, allowing them to be used across multiple simulators and archived in a standardized format. Here we describe the structure of NeuroML and demonstrate its scope by converting into NeuroML models of a number of different voltage- and ligand-gated conductances, models of electrical coupling, synaptic transmission and short-term plasticity, together with morphologically detailed models of individual neurons. We have also used these NeuroML-based components to develop an highly detailed cortical network model. NeuroML-based model descriptions were validated by demonstrating similar model behavior across five independently developed simulators. Although our results confirm that simulations run on different simulators converge, they reveal limits to model interoperability, by showing that for some models convergence only occurs at high levels of spatial and temporal discretisation, when the computational overhead is high. Our development of NeuroML as a common description language for biophysically detailed neuronal and network models enables interoperability across multiple simulation environments, thereby improving model transparency, accessibility and reuse in computational neuroscience

    Acute and repetitive fronto-cerebellar tDCS stimulation improves mood in non-depressed participants

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    25th annual computational neuroscience meeting: CNS-2016

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    The same neuron may play different functional roles in the neural circuits to which it belongs. For example, neurons in the Tritonia pedal ganglia may participate in variable phases of the swim motor rhythms [1]. While such neuronal functional variability is likely to play a major role the delivery of the functionality of neural systems, it is difficult to study it in most nervous systems. We work on the pyloric rhythm network of the crustacean stomatogastric ganglion (STG) [2]. Typically network models of the STG treat neurons of the same functional type as a single model neuron (e.g. PD neurons), assuming the same conductance parameters for these neurons and implying their synchronous firing [3, 4]. However, simultaneous recording of PD neurons shows differences between the timings of spikes of these neurons. This may indicate functional variability of these neurons. Here we modelled separately the two PD neurons of the STG in a multi-neuron model of the pyloric network. Our neuron models comply with known correlations between conductance parameters of ionic currents. Our results reproduce the experimental finding of increasing spike time distance between spikes originating from the two model PD neurons during their synchronised burst phase. The PD neuron with the larger calcium conductance generates its spikes before the other PD neuron. Larger potassium conductance values in the follower neuron imply longer delays between spikes, see Fig. 17.Neuromodulators change the conductance parameters of neurons and maintain the ratios of these parameters [5]. Our results show that such changes may shift the individual contribution of two PD neurons to the PD-phase of the pyloric rhythm altering their functionality within this rhythm. Our work paves the way towards an accessible experimental and computational framework for the analysis of the mechanisms and impact of functional variability of neurons within the neural circuits to which they belong

    Social Rights and Market Forces: Is the open coordination of employment and social policies the future of Social Europe?

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    This collection of essays examines the development of new modes of governance in the European Union, asking whether - and under which conditions - these new modes of governance offer a way out of the dilemmas which have plagued debates on ‘Social Europe’ since the very creation of the European Economic Community, and whether they may inspire developments in other fields. We focus in particular on the open method of coordination, both as an element of the European Employment Strategy and as a tool in the social policy. The open method of coordination is one of a number of new governance mechanisms which seek to foster mutual learning between the Member States and to limit the phenomenon of competitive deregulation in the internal market, while at the same time respecting the diversity of national practices and the existing division of powers between the European Community and the Member States. We sought to confront the practice of the open method of coordination with a number of different approaches to collective action proposed within the current debate on modes of governance. Our hypothesis was that the notion of ‘reflexive governance’ might serve to identify existing limitations of the current model under which the open method of coordination functions, and to help us come up with possible solutions for overcoming these limitations, especially as the open method of coordination may expand to other policy areas
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