Multiplicative Auditory Spatial Receptive Fields Created by a Hierarchy of Population Codes

A multiplicative combination of tuning to interaural time difference (ITD) and interaural level difference (ILD) contributes to the generation of spatially selective auditory neurons in the owl's midbrain. Previous analyses of multiplicative responses in the owl have not taken into consideration the frequency-dependence of ITD and ILD cues that occur under natural listening conditions. Here, we present a model for the responses of ITD- and ILD-sensitive neurons in the barn owl's inferior colliculus which satisfies constraints raised by experimental data on frequency convergence, multiplicative interaction of ITD and ILD, and response properties of afferent neurons. We propose that multiplication between ITD- and ILD-dependent signals occurs only within frequency channels and that frequency integration occurs using a linear-threshold mechanism. The model reproduces the experimentally observed nonlinear responses to ITD and ILD in the inferior colliculus, with greater accuracy than previous models. We show that linear-threshold frequency integration allows the system to represent multiple sound sources with natural sound localization cues, whereas multiplicative frequency integration does not. Nonlinear responses in the owl's inferior colliculus can thus be generated using a combination of cellular and network mechanisms, showing that multiple elements of previous theories can be combined in a single system

Cross-Correlation in the Auditory Coincidence Detectors of Owls

Interaural time difference (ITD) plays a central role in many auditory functions, most importantly in sound localization. The classic model for how ITD is computed was put forth by Jeffress (1948). One of the predictions of the Jeffress model is that the neurons that compute ITD should behave as cross-correlators. Whereas cross-correlation-like properties of the ITD-computing neurons have been reported, attempts to show that the shape of the ITD response function is determined by the spectral tuning of the neuron, a core prediction of cross-correlation, have been unsuccessful. Using reverse correlation analysis, we demonstrate in the barn owl that the relationship between the spectral tuning and the ITD response of the ITD-computing neurons is that predicted by cross-correlation. Moreover, we show that a model of coincidence detector responses derived from responses to binaurally uncorrelated noise is consistent with binaural interaction based on cross-correlation. These results are thus consistent with one of the key tenets of the Jeffress model. Our work sets forth both the methodology to answer whether cross-correlation describes coincidence detector responses and a demonstration that in the barn owl, the result is that expected by theory

The Strength of the Deed: Notarial Credit Markets and Contract Enforcement Institutions in Early Modern Spain

[eng] The present study aims to contribute to the analysis on the capacity of contract enforcement institutions in early modern Spain to protect private property rights, thus encouraging the development of markets. In order to do this I focus on the role played by the aforementioned institutions within the notarial credit market of the city of Malaga in the second half of the eighteenth century. Chapter 1 studies the legal advantages that notarized contracts offered in the Crown of Castile, as well as those financial segments that benefited from them the most. Chapter 2 measures the degree of flexibility enjoyed by the notarial credit market in introducing legal adaptations in the absence of changes to Castilian statutory law. Finally, chapter 3 assesses whether the public mortgage registries, created in 1768, contributed to the better functioning of the notarial credit market.[spa] El presente trabajo pretende contribuir al análisis sobre la capacidad de las instituciones contractuales españolas durante el Antiguo Régimen para proteger los derechos de propiedad privados, incentivando así el desarrollo de los mercados. Para ello, me centro en el papel desempeñado por dichas instituciones dentro del mercado notarial de crédito de la ciudad de Málaga en la segunda mitad del siglo XVIII. El capítulo 1 estudia las ventajas legales de los contratos notarizados en la Corona de Castilla, así como aquellos segmentos financieros que más se beneficiaron de ellas. El capítulo 2 analiza el grado de flexibilidad del mercado notarial de crédito para introducir adaptaciones legales en ausencia de modificaciones en la ley escrita castellana. Finalmente, el capítulo 3 evalúa si los oficios de hipotecas, creados en 1768, contribuyeron a un mejor funcionamiento del mercado notarial de crédito

From Postsynaptic Potentials to Spikes in the Genesis of Auditory Spatial Receptive Fields

Space-specific neurons in the owl's inferior colliculus respond only to a sound coming from a particular direction, which is equivalent to a specific combination of interaural time difference (ITD) and interaural level difference (ILD). Comparison of subthreshold postsynaptic potentials (PSPs) and spike output for the same neurons showed that receptive fields measured in PSPs were much larger than those measured in spikes in both ITD and ILD dimensions. Space-specific neurons fire more spikes for a particular ITD than for its phase equivalents (ITD +/- 1/F, where F is best frequency). This differential response was much less pronounced in PSPs. The two sides of pyramid-shaped ILD curves were more symmetrical in spikes than in PSPs. Furthermore, monaural stimuli that were ineffective in eliciting spikes induced subthreshold PSPs. The main cause of these changes between PSPs and spikes is thresholding. The spiking threshold did not vary with the kind of acoustic stimuli presented. However, the thresholds of sound-induced first spikes were lower than those of later sound-induced and spontaneous spikes. This change in threshold may account for the sharpening of ITD selectivity during the stimulus. Large changes in receptive fields across single neurons are not unique to the owl's space-specific neurons but occur in mammalian visual and somatosensory cortices, suggesting the existence of general principles in the formation of receptive fields in high-order neurons

Geomorphology of the northern sector of the Alfambra- Teruel depression (Iberian Ranges, NE Spain)

The area of Alfambra (NE Spain) is very representative of the relief evolution of the Eastern Iberian ranges. It contains the main geomorphological elements that illustrate this evolutionary process. The geomorphological cartography includes the northern sector of the Alfambra-Teruel Neogene depression and its mountainous surroundings. The cartographic process started by using aerial photographs (1:30000 scale) and fieldwork. Later, the document was projected to the UTM Zone 30 system with ETRS_1989 Datum introduced to ArcGIS 10.1. The legend follows a chronological order. The structural reliefs, erosion surfaces, karst landforms, Quaternary pediments and terraces, and fluvial network are represented over a lithological background. The main cartography is complemented with two maps of lithological and geomorphological units. The obtained information enabled the main geological and geomorphological stages of the regional relief to be established.Fil: Sánchez Fabre, Miguel. Universidad de Zaragoza. Facultad de Filosofía y Letras; EspañaFil: Peña Monné, José Luis. Universidad de Zaragoza. Facultad de Filosofía y Letras; EspañaFil: Sampietro Vattuone, Maria Marta. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo. Laboratorio de Geoarqueología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán; Argentin

Televisión digital y programación : de la televisión de siempre a la televisión de pago y multicanal

El presente artículo analiza la evolución de la programación en las televisiones en España desde sus inicios a mediados de los años cincuenta con una televisión pública y en blanco y negro hasta la televisión digital multicanal de pago. A pesar de los años transcurridos y de los avances tecnológicos que se han producido la programación no ha variado sustancialmente. Lo que sí ha cambiado ha sido la cantidad de la oferta y la presentación al público; ahora por áreas temáticas

Intervention in the Church Square in Rugat. Rugat, Valencia, Spain.

[EN] This paper describes one of the projects carried out in Rugat, a small village in the Albaida Valley in Valencia (Spain) on a low budget obtained from FEDER funds. The aim was to renovate the somewhat degraded available public space of the urban environment. In both cases concrete was used as the essential material, adapting its formal possibilities, color and texture to the conditions of each site. Besides improving access and the connections with existing buildings and streets, the local council wished to recover small leisure spaces and meeting places with the minimum standards of quality and dignity. The spaces’ only common interest was the presence of small public fountains, previously out of service, which were included in the renovation. The Church Square project consisted of recovering and renovating a public space in Rugat even though, due to its reduced size, could not originally be considered a public square. Neither was it the traditional public space that contained the village church, in spite of being close to it, but was created as the result of a bend in the road that passes through the village.[ES] Se presenta una de las dos actuaciones realizadas en Rugat, una pequeña población de la Vall d’Albaida (Valencia), de bajísimo presupuesto, obtenido de fondos FEDER, cuyo objetivo fue regenerar el entorno urbano, mediante la intervención en el escaso y degradado espacio público disponible. Ambos casos emplearon hormigón visto como material esencial, adaptando sus posibilidades formales, color y textura, a las posibilidades de cada emplazamiento. Además de mejorar accesos y conexión a edificios y calles existentes, el ayuntamiento deseaba obtener pequeños lugares de estancia y reunión para los vecinos, que otorgasen un mínimo de calidad y dignidad a estos espacios, cuyo único interés compartido era la presencia de sendas pequeñas fuentes públicas, entonces en desuso, que fueron incorporadas a la renovación urbana. La intervención realizada en la Plaza de la Iglesia consistía en recuperar y dignificar un espacio urbano público para el pueblo de Rugat. Sin embargo, en su estado original, este espacio no se puede considerar una plaza, por sus pequeñas dimensiones; y aunque está cerca de la Iglesia, tampoco es el tradicional espacio público donde se levanta la iglesia del pueblo, sino que este espacio es producto de una irregularidad en la trama urbana, un ligero ensanchamiento del trazado viario.Peña Cerdán, A.; Alapont Ramón, JL. (2018). Intervención en la Plaza de la Iglesia de Rugat, Valencia, España. En CIAB 8. VIII Congreso Internacional de arquitectura blanca. Editorial Universitat Politècnica de València. 118-125. https://doi.org/10.4995/CIAB8.2018.7586OCS11812

Intervention on the Serreta Fountain. Rugat, Valencia, Spain.

[EN] This paper describes two low-budget interventions carried out in Rugat, a small village in the Albaida Valley in Valencia, financed by FEDER funds. The aim was to regenerate the urban environment of the small and somewhat deteriorated available public space. In both cases concrete was used as the essential material, adapting its formal possibilities, color and texture to the conditions of each site. Besides improving access and the connections with existing buildings and streets, the local council wished to recover small leisure spaces and meeting places with the minimum standards of quality and dignity. The spaces’ only common interest was the presence of small public fountains, previously out of service, which were included in the renovation. The Serreta Fountain was on a corner between two curving streets on a steep slope. The challenge here was to merge the vertical aspect of the terrain with the horizontal design of the program, organized into two levels, connecting both streets with the fountain below and a platform above that acted as both balcony and protection. The entire project was achieved with a single piece of concrete that acted as foundation, steps, bench, wall, slab and pavement, with a masonry wall and spectacular tree in the background.[ES] Se presenta una de las dos actuaciones realizadas en Rugat, una pequeña población de la Vall d’Albaida (Valencia), de bajísimo presupuesto, obtenido de fondos FEDER, cuyo objetivo fue regenerar el entorno urbano, mediante la intervención en el escaso y degradado espacio público disponible. Ambos casos emplearon hormigón visto como material esencial, adaptando sus posibilidaddes formales, color y textura, a las posibilidades de cada emplazamiento. Además de mejorar accesos y conexión a edificios y calles existentes, el ayuntamiento deseaba obtener pequeños lugares de estancia y reunión para los vecinos, que otorgasen un mínimo de calidad y dignidad a estos espacios, cuyo único interés compartido era la presencia de sendas pequeñas fuentes públicas, entonces en desuso, que fueron incorporadas a la renovación urbana. La Fuente de la Serreta, ocupa un rincón entre dos calles curvas en acusado desnivel. La apuesta fue conciliar la verticalidad del terreno con la horizontalidad del programa, organizado en dos niveles, conectando ambas calles, con la fuente abajo y una plataforma superior, a la vez balcón y protección. Todo se resolvió con una única pieza de hormigón, a la vez cimiento, escalera, banco, muro, losa y pavimento, con un muro de mampostería y un fantástico árbol como fondo.Alapont Ramón, JL.; Peña Cerdán, A. (2018). Intervención en la Fuente de la Serreta. Rugat, Valencia, España. En CIAB 8. VIII Congreso Internacional de arquitectura blanca. Editorial Universitat Politècnica de València. 110-117. https://doi.org/10.4995/CIAB8.2018.7583OCS11011

El corcho y el alcornoque en Extremadura

Se realiza una descripción, asentamiento y localización del corcho en Extremadura, de sus características, forma de obtenerlo y producción. Se analiza la industria, con una pequeña introducción a una serie de datos, que sirven para comparar España con Portugal como primer país productor y exportador; un estudio de la producción de la industria extremeña y otro concreto de una fábrica extremeña transformadora. Para completar el trabajo habría sido necesario un cuarto punto que tratara del comercio del corcho.We have made a description of the settlement and cork location in Extremadura. We want to know their characteristics, how to obtain and product it. The industry is analyzed and is compared Spain and Portugal as the first producer and exporter. To complete the work would have been necessary to try a fourth point of the cork trade.notPeerReviewe