Synaptic depression and slow oscillatory activity in a biophysical network model of the cerebral cortex

Short-term synaptic depression (STD) is a form of synaptic plasticity that has a large impact on network computations. Experimental results suggest that STD is modulated by cortical activity, decreasing with activity in the network and increasing during silent states. Here, we explored different activity-modulation protocols in a biophysical network model for which the model displayed less STD when the network was active than when it was silent, in agreement with experimental results. Furthermore, we studied how trains of synaptic potentials had lesser decay during periods of activity (UP states) than during silent periods (DOWN states), providing new experimental predictions. We next tackled the inverse question of what is the impact of modifying STD parameters on the emergent activity of the network, a question difficult to answer experimentally. We found that synaptic depression of cortical connections had a critical role to determine the regime of rhythmic cortical activity. While low STD resulted in an emergent rhythmic activity with short UP states and long DOWN states, increasing STD resulted in longer and more frequent UP states interleaved with short silent periods. A still higher synaptic depression set the network into a non-oscillatory firing regime where DOWN states no longer occurred. The speed of propagation of UP states along the network was not found to be modulated by STD during the oscillatory regime; it remained relatively stable over a range of values of STD. Overall, we found that the mutual interactions between synaptic depression and ongoing network activity are critical to determine the mechanisms that modulate cortical emergent patterns.

Entry Regulation Asymmetries and Gasoline Competition in a Mixed Motorway Network

Regulatory and funding asymmetries in the Spanish motorway network produce huge differences in the structure of gasoline markets by motorway type: free or toll. While competition is encouraged among gas stations on free motorways, the regulations for toll motorways allow private concessionaires to auction all gas stations to the same provider, thereby limiting competition and consolidating market power. This paper reports how this regulatory asymmetry results in higher prices and fewer gas stations. Specifically, we show that competition is constrained on toll motorways by the granting of geographical monopolies, resulting in a small number of rivals operating in close proximity to each other, and allowing gas stations to operate as local monopolies. The lack of competition would seem to account for the price differential between toll and free motorways. According to available evidence, deregulation measures affecting toll motorway concessions could help to mitigate price inefficiencies and increase consumer welfare.

What is the meaning of ‘talent’ in the world of work?

The ongoing confusion about the meaning of ‘talent’ within the world of work is hindering the establishment of widely accepted talent management theories and practices. The aim of this paper is to contribute to the literature on talent management by offering an in-depth review of the talent concept within the specific context of the world of work, and proposing a framework for its conceptualization. We group different theoretical approaches to talent into ‘object’ (i.e., talent as natural ability; talent as mastery; talent as commitment; talent as fit) versus ‘subject’ approaches (i.e., talent as all people; talent as some people) and identify dynamics existing within and between them, as well as implications for talent management theory and practice. Finally, we discuss different avenues for further research aimed at developing the talent—and consequently, the talent management—construct further.

Urban transport governance reform in Barcelona

The unusual mixed public-private structure of the urban bus market in the metropolitan area of Barcelona provides an interesting context in which to analyze the management challenges and opportunities of the partial privatization of public services. Initiatives used by the public regulator to promote competition for contracts, such as short term concessions to private contractors and the removal of entry barriers, have considerable potential for improving efficiency and quality. The growth in the share of routes managed by private firms in recent years shows that privatization is a credible threat that may well stimulate improved performance among public managers. The type of reform implemented in Barcelona is of interest to all metropolitan areas large enough to operate under constant returns to scale regimes, and suitable for potential concessions of routes in segregated areas inside the metropolitan area, so as not to miss out on the benefits of economies of density.