La economía de la literatura en la Regeneración colombiana: el centro estratégico y algunas tácticas

El incipiente campo intelectual colombiano había ido ganando una importante independencia hasta la década de 1870. La libertad total de prensa garantizaba la posibilidad de un lugar para cualquier iniciativa cultural, literaria o periodística que contara con el capital para llevarla a cabo. En las décadas siguientes el régimen político cambió y generó unas nuevas reglas de juego para quienes querían participar de la esfera pública. Los regeneradores no sólo regularon la libertad de prensa, sino que participaron activamente en la restauración de una potente economía de la literatura y del sentido, representada en metáforas con imaginarios de la comunidad, la mujer y la confrontación misma, muy cercanos a los de la colonia. En este informe se busca rastrear esa economía, en los diferentes formatos por los que transitaba, e interpretarla desde una lectura estética sistemática, que permita comprender el cambio de régimen del arte, con sus correspondientes resistencias literarias y periodísticas

“Cali, capital mundial de la salsa”. Fundación de un mito: mapas prácticas y heroínas

El texto “>. Fundación de un mito: mapas prácticas y heroínas”, como su largo título indica, constituye el inicio de una búsqueda por interpretar la fundación del mito contemporáneo de la ciudad de Cali como “capital mundial de la salsa”. Para lograrlo, se hace una interpretación sistemática de las prácticas culturales salseras desde los relatos de varios “héroes”, “heroínas” y “mapas” que el autor organiza desde una apuesta por la diversidad de voces: los de la obra Celia Cruz: Reina Rumba de Umberto Valverde y los bailadores de los 50, en los barrios en los que empezó la “rumba” caleña de la “música antillana”; los de los cuentos de Andrés Caicedo y, en especial la heroína de la novela ¡Que viva la música!, representantes de la rumba, ya plenamente “salsera” de finales de los años 60 y los 70, y el surgimiento de la salsa ya no sectorizada, sino como una práctica asumida como parte de “la ciudad”; dos de las canciones del Grupo Niche que permiten evidenciar la problemática de una ciudad habitada por un gran número de migrantes (empezando por el autor), que se afincaron en barrios periféricos y “de invasión”. La parte final de la investigación está compuesta por el relato oral de un grupo de bailarines profesionales que dan testimonio de sus propias prácticas salseras, desde los años 40 hasta la actualidad. Sus testimonios ponen en primer plano el conflicto profundo de negociación simbólica, que significó su apuesta por las prácticas culturales que ahora son parte de una memoria colectiva de la ciudad. Como bailadores en un principio, y bailarines cuando su estatus profesional fue aceptado, ellos son los héroes y heroínas principales de esta apuesta por interpretar la compleja formación del mito de “Cali, capital mundial de la salsa”. Ellos establecieron las más importantes prácticas salseras y construyeron los mapas simbólicos de la ciudad salsera

Continuum modelling of gigahertz nano-oscillators

Fullerenes and carbon nanotubes are of considerable interest throughout many scientific areas due to their unique and exceptional properties, such as low weight, high strength, flexibility, high thermal conductivity and chemical stability. These nanostructures have many potential applications in nano-devices. One concept that has attracted much attention is the creation of nano-oscillators, which can produce frequencies in the gigahertz range, for applications such as ultra-fast optical filters and nano-antennae. In this paper, we provide the underlying mechanisms of the gigahertz nano-oscillators and we review some recent results derived by the authors using the Lennard-Jones potential together with the continuum approach to mathematically model three different types of nano-oscillators including double-walled carbon nanotube, C60-nanotube and C60-nanotorus oscillators

The Pi-puck extension board: a Raspberry Pi interface for the e-puck robot platform

This paper presents the Pi-puck extension board - an interface between the e-puck robot platform and a Raspberry Pi single-board computer that enhances the processing power, memory capacity, and networking capabilities of the robot at a low cost. It allows high-level control algorithms, wireless communication, and computationally expensive operations such as real-time image processing to be handled by a Raspberry Pi, while the e-puck's microcontroller deals with low-level motor control and sensor interfacing. Although two similar extension boards for the e-puck robot platform already exist, they are now out-dated and expensive in comparison. Our open-source hardware design and supporting software infrastructure offer an inexpensive upgrade to the e-puck robot, transforming it into the Pi-puck – a modern and flexible new platform for mobile robotics research

Prospects for local co-governance

British local authorities and their partners are increasingly developing new ways of working together with local communities. The nature of this co-working, however, is complex, multi-faceted and little understood. This article argues for greater clarity of thinking on the topic, by analysing this co-working as a form of political co-governance, and drawing attention in particular to issues of scale and democracy. Using evidence from a study of 43 local authority areas, 16 authorities are identified where co-governance is practised, following three main types of approach: service-influencing, service-delivering and parish council developing. It is concluded that strengthening political co-governance is essential for a healthy democracy

Exploring Self-Repair in a Coupled Spiking Astrocyte Neural Network

It is now known that astrocytes modulate the activity at the tripartite synapses where indirect signaling via the retrograde messengers, endocannabinoids, leads to a localized self-repairing capability. In this paper, a self-repairing spiking astrocyte neural network (SANN) is proposed to demonstrate a distributed self-repairing capability at the network level. The SANN uses a novel learning rule that combines the spike-timing-dependent plasticity (STDP) and Bienenstock, Cooper, and Munro (BCM) learning rules (hereafter referred to as the BSTDP rule). In this learning rule, the synaptic weight potentiation is not only driven by the temporal difference between the presynaptic and postsynaptic neuron firing times but also by the postsynaptic neuron activity. We will show in this paper that the BSTDP modulates the height of the plasticity window to establish an input-output mapping (in the learning phase) and also maintains this mapping (via self-repair) if synaptic pathways become dysfunctional. It is the functional dependence of postsynaptic neuron firing activity on the height of the plasticity window that underpins how the proposed SANN self-repairs on the fly. The SANN also uses the coupling between the tripartite synapses and γ -GABAergic interneurons. This interaction gives rise to a presynaptic neuron frequency filtering capability that serves to route information, represented as spike trains, to different neurons in the subsequent layers of the SANN. The proposed SANN follows a feedforward architecture with multiple interneuron pathways and astrocytes modulate synaptic activity at the hidden and output neuronal layers. The self-repairing capability will be demonstrated in a robotic obstacle avoidance application, and the simulation results will show that the SANN can maintain learned maneuvers at synaptic fault densities of up to 80% regardless of the fault locations

Restricted three body problems at the nanoscale

In this paper, we investigate some of the classical restricted three body problems at the nanoscale, such as the circular planar restricted problem for three C60 fullerenes, and a carbon atom and two C60 fullerenes. We model the van der Waals forces between the fullerenes by the Lennard-Jones potential. In particular, the pairwise potential energies between the carbon atoms on the fullerenes are approximated by the continuous approach, so that the total molecular energy between two fullerenes can be determined analytically. Since we assume that such interactions between the molecules occur at sufficiently large distance, the classical three body problems analysis is legitimate to determine the collective angular velocity of the two and three C60 fullerenes at the nanoscale. We find that the maximum angular frequency of the two and three fullerenes systems reach the terahertz range and we determine the stationary points and the points which have maximum velocity for the carbon atom for the carbon atom and the two fullerenes system

Flow through a circular tube with a permeable Navier slip boundary

For Newtonian fluid flow in a right circular tube, with a linear Navier slip boundary, we show that a second flow field arises which is different to conventional Poiseuille flow in the sense that the corresponding pressure is quadratic in its dependence on the length along the tube, rather than a linear dependence which applies for conventional Poiseuille flow. However, assuming that the quadratic pressure is determined, say from known experimental data, then the new solution only exists for a precisely prescribed permeability along the boundary. While this cannot occur for conventional pipe flow, for fluid flow through carbon nanotubes embedded in a porous matrix, it may well be an entirely realistic possibility, and could well explain some of the high flow rates which have been reported in the literature. Alternatively, if the radial boundary flow is prescribed, then the new flow field exists only for a given quadratic pressure. Our primary purpose here is to demonstrate the existence of a new pipe flow field for a permeable Navier slip boundary and to present a numerical solution and two approximate analytical solutions. The maximum flow rate possible for the new solution is precisely twice that for the conventional Poiseuille flow, which occurs for constant inward directed flow across the boundary

Bio-inspired Anomaly Detection for Low-cost Gas Sensors

This paper proposes a novel anomaly detection method for gas sensors using spiking neural network principles. The synapse models with excitatory/inhibitory responses and a single spiking neuron are employed to develop the bio-inspired anomaly detector for a single gas sensor. The approach can detect anomalies in the data, which is collected by the gas sensor by identifying rapid changes rather than a magnitude threshold. In particular, the false-positive detections due to the drifts of low-cost sensors are minimised using the proposed bio-inspired approach. Using the chemicals of surgical spirits and isobutanol as test substances, experiments were carried out to evaluate the proposed method. Results demonstrate that gas anomalies can be detected when the chemical substances are presented to the sensor. In addition, results show that the approach can detect under the presence of sensor drift. The proposed bio-inspired detector was implemented on FPGA hardware, which demonstrates relatively low resources. Compact and energy efficient CMOS-based implementations of the synapse are also available which supports the low-cost potential applications of this approach, e.g. use in safety with drones and ground robots in hazardous scene detection