A 64-channel inductively-powered neural recording sensor array

This paper reports a 64-channel inductively powered neural recording sensor array. Neural signals are acquired, filtered, digitized and compressed in the channels. Additionally, each channel implements a local auto-calibration mechanism which configures the transfer characteristics of the recording site. The system has two operation modes; in one case the information captured by the channels is sent as uncompressed raw data; in the other, feature vectors extracted from the detected neural spikes are transmitted. Data streams coming from the channels are serialized by an embedded digital processor and transferred to the outside by means of the same inductive link used for powering the system. Simulation results show that the power consumption of the complete system is 377μW.Ministerio de Ciencia e Innovación TEC2009-0844

A power efficient neural spike recording channel with data bandwidth reduction

This paper presents a mixed-signal neural spike recording channel which features, as an added value, a simple and low-power data compression mechanism. The channel uses a band-limited differential low noise amplifier and a binary search data converter, together with other digital and analog blocks for control, programming and spike characterization. The channel offers a self-calibration operation mode and it can be configured both for signal tracking (to raw digitize the acquired neural waveform) and feature extraction (to build a first-order PWL approximation of the spikes). The prototype has been fabricated in a standard CMOS 0.13μm and occupies 400μm×400μm. The overall power consumption of the channel during signal tracking is 2.8μW and increases to 3.0μW average when the feature extraction operation mode is programmed.Ministerio de Ciencia e Innovación TEC2009-08447Junta de Andalucía TIC-0281

Escenografía medieval para un alojamiento turístico: parador nacional de Sigüenza (Guadalajara)

R esumen: El parador de Sigüenza es uno de los establecimientos más emblemáticos de la Red de Paradores, al que desde su creación le ha perseguido una cierta polémica en relación a la intervención patrimonial que sufrió el monumento en la rehabilitación hotelera. Este artículo pretende desvelar cuáles fueron las claves de aquella intervención, los criterios patrimoniales empleados, su gestación y resultado final, que aunque aparentemente se manifiesten nítidos en la obra, esconde un complejo proceso en el que colaboraron conjuntamente varias Administraciones. Abstract : Sigüenza's inn is one of the most emblematic establishments of the 'Red de Paradores'. From its creation, it has been plagued by controversy relating to the intervention it underwent during the hotel’s refurbishing. This article seeks to reveal the keys of that intervention, the criteria used concerning from a heritage perspective, the inception and final outcome, which, though they appear to be clear in the work, hide a complex process in which several Administrations worked together

Restauración y cambio de uso del Castillo de la Zuda como establecimiento hotelero: parador de turismo de Tortosa

El turismo comenzó a entenderse en España como herramienta para la gestión del patri-monio desde la segunda década del siglo XX, cuando la Comisaría Regia, iniciaba de forma sucesiva la construcción de los dos primeros establecimientos de la Red de Paradores. Aque-llas primeras actuaciones se transformaron, con el correr del tiempo, en un extenso patrimo-nio, cuya marca de identidad fue la creación de una infraestructura hotelera a partir de la rehabilitación de edificios históricos. El artículo muestra uno de los casos más significativos de la red, en el que la implantación de un parador de nueva planta en el recinto del castillo de la Zuda se revela como el último eslabón de una larga cadena de reuso de construcciones militares, en el que se culminaba toda la experiencia adquirid

El papel de la categorización como medio de preservación de la fidelidad en la transmisión cultural

This paper deals with the problem of identifying cultural replicators and providing a plausible replication model for culture. Depending on what kind of information is considered to be replicated, the different evolutionary models of cultural transmission are clustered into three main groups which are referred to as externalism, internalism and multi-substratism. From these, internalism is argued to be the most plausible position, but it fails in explaining how cultural information can be faithfully replicated in our species despite essentially depending on individual processes of intentional inference. It is concluded that no author seems to have fittingly adopted a categorization model stemmed from a usage-based perspective, and such a model would entail a feedback dynamic in category formation which could allow for an a posteriori purification of the input information flow. This way, categorization would partially equate the role of DNA in genetic transmission cycles.En este artículo se aborda la problemática de la identificación de los replicadores culturales y la elaboración de un modelo de replicación cultural verosímil. De acuerdo con el tipo de información que se supone objeto de replicación agrupamos los diversos modelos evolutivos de transmisión cultural en tres grandes categorías, que denominamos externalismo, internalismo y polisustratismo. De ellas, argumentamos por qué, a nuestro juicio, el internalismo es la opción más adecuada; si bien los modelos internalistas no suelen dar cuenta satisfactoriamente de cómo la información cultural puede haber alcanzado un cierto grado de fidelidad en la transmisión pese a depender de procesos individuales de inferencia intencional. Concluimos que ningún autor parece haber adoptado un modelo adecuado de categorización fundamentado en una perspectiva basada en el uso. Tal modelo implicaría una dinámica de retroalimentación en la formación de las categorías que podría permitir la depuración a posteriori del flujo de información entrante

Experimental study for the determination of the turbulence onset in natural convection on inclined plates

In June, 8th, 2009 the balloon-borne solar telescope SUNRISE was launched from the Swedish Space Corporation balloon facility Esrange. A telescope with a mirror of 1 m in diameter ob-served the Sun during six days until the mission was terminated in Canada. The design process of SUNRISE and of any optical telescope requires the analysis of the effect of surrounding air on the quality of images. The turbulence encountered in the local telescope environment de-grades its optical performance. This phenomenon called `seeing' consists of optical aberrations produced by density non-homogeneities in the air along the optical path. The refraction index of air changes due to thermal non-uniformities so that the wavefront incident on the mirror is randomly distorted, and therefore, images are altered. When telescope mirrors are heated, as it happens in solar telescopes, and therefore they are at a temperature different from the environment's, natural convection occurs. It is then crucial to know whether the flow in front of the mirror is laminar or turbulent. After reviewing the literature, it was found that the scattering of results about the onset of the transition gives only rough orders of magnitude of the values of the critical Grashof numbers. Aiming to obtain more information about it, the problem of determination of the turbulence onset in natural convection on heated inclined plates in air environment was experimentally revisited. The transition has been determined from hot wire velocity measurements. The onset of turbulence has been considered to take place where velocity perturbations start to grow. Experiments have shown that the onset depends not only on the Grashof number, but also on other parameters as the temperature difference between the heated plate and the surrounding air. A correlation between dimensionless Grashof and Reynolds numbers has been obtained, fitting extraordinarily well the experimental data. The results are obtained in terms of non-dimensional numbers, this way they apply to any air pressure and therefore to any floating altitud