A geometric approach to phase response curves and its numerical computation through the parameterization method

The final publication is available at link.springer.comThe phase response curve (PRC) is a tool used in neuroscience that measures the phase shift experienced by an oscillator due to a perturbation applied at different phases of the limit cycle. In this paper, we present a new approach to PRCs based on the parameterization method. The underlying idea relies on the construction of a periodic system whose corresponding stroboscopic map has an invariant curve. We demonstrate the relationship between the internal dynamics of this invariant curve and the PRC, which yields a method to numerically compute the PRCs. Moreover, we link the existence properties of this invariant curve as the amplitude of the perturbation is increased with changes in the PRC waveform and with the geometry of isochrons. The invariant curve and its dynamics will be computed by means of the parameterization method consisting of solving an invariance equation. We show that the method to compute the PRC can be extended beyond the breakdown of the curve by means of introducing a modified invariance equation. The method also computes the amplitude response functions (ARCs) which provide information on the displacement away from the oscillator due to the effects of the perturbation. Finally, we apply the method to several classical models in neuroscience to illustrate how the results herein extend the framework of computation and interpretation of the PRC and ARC for perturbations of large amplitude and not necessarily pulsatile.Peer ReviewedPostprint (author's final draft

2D-to-3D facial expression transfer

© 20xx IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.Automatically changing the expression and physical features of a face from an input image is a topic that has been traditionally tackled in a 2D domain. In this paper, we bring this problem to 3D and propose a framework that given an input RGB video of a human face under a neutral expression, initially computes his/her 3D shape and then performs a transfer to a new and potentially non-observed expression. For this purpose, we parameterize the rest shape --obtained from standard factorization approaches over the input video-- using a triangular mesh which is further clustered into larger macro-segments. The expression transfer problem is then posed as a direct mapping between this shape and a source shape, such as the blend shapes of an off-the-shelf 3D dataset of human facial expressions. The mapping is resolved to be geometrically consistent between 3D models by requiring points in specific regions to map on semantic equivalent regions. We validate the approach on several synthetic and real examples of input faces that largely differ from the source shapes, yielding very realistic expression transfers even in cases with topology changes, such as a synthetic video sequence of a single-eyed cyclops.Peer ReviewedPostprint (author's final draft

Revisión de los Ammonoideos del Lías español depositados en el Museo Geominero (ITGE, Madrid)

Se revisan desde el punto de vista taxonómico, los fósiles de ammonoideos correspondientes al Lías español que se encuentran depositados en el Museo Geominero. La colección está compuesta por ejemplares procedentes de 67 localidades españolas, pertenecientes a colecciones de diferentes autores. Se identifican los ordenes Phylloceratina, Lytoceratina y Ammonitina, las familias Phylloceratidae, Echioceratidae, eoderoceratidae, Liparoceratidae, Amaltheidae, Dactylioceratidae, Hildoceratidae y Hammatoceratidae y las subfamilias Xipheroceratinae, Arieticeratinae, Harpoceratinae, Hildoceratinae, Grammoceratinae, Phymatoceratinae y Hammatoceratinae correspondientes a los pisos Sinemuriense, Pliensbachiense y Toarciense

Migrant Heritage: A Dialogue of Objects and Memories in a Barcelona Ethnographic Museum

This article describes the 'Dialogues with Africa' project of the Barcelona Museum of World Cultures, which consisted of workshops using personal objects of African guests residing in Catalonia, and objects from the museum's African collections. The dialogues revealed the existence of both a migrant memory connected with objects chosen for their capacity to evoke origins and a museum memory linked with artifacts that were chosen as representing distant cultures. The main aim is to describe this migrant memory in relation to the objects and analyze how it connects with the museum's institutional memory in order to contribute to the discussion of the role of ethnographic museums in a plural society. We suggest that incorporating migrant memory will make possible an opening up to new meanings for objects that have been turned into heritage from an exoticizing standpoint, and that this is in keeping with a more inclusive anthropological museology

Control de sistemes no holònoms mitjançant la forma normal de Goursat

La principal contribució d'aquest treball és donar les eines i les pautes necessàries per a la linealització per realimentació dels sistemes no holònoms de dues entrades a través del disseny de la forma normal de Goursat. Dissenyarem controladors, de manera que les trajectòries solució passin per unes certes condicions inicials i nals imposades.. Pels braços robòtics tridimensionals a l'espai, i, per tant, no sotmesos a forces externes com la gravetat, les equacions resultants formen un sistema de control no holònom. Si a cada articulació s'hi posa tres motors, els sistema té tres graus de subactuació.A la literatura s'ha dissenyat i controlat sistemes d'auest estil amb dos motors extres a la base a fi que tingui només un grau de subactuació. Es tracta de trobar les condicions a fi que es puguin planificar i fer seguiment de trajectòries en el cas de dos graus de subactuació

Com influeix el currículum ocult en la inclusió i/o exclusió dels alumnes ?

Curs 2012-2013L’objectiu d'aquest treball és observar si hi ha elements del currículum ocult en tres aules de Manresa i si aquests afecten a la inclusió i/o exclusió dels alumnes. Per a fer-ho partim d’una base teòrica on hi ha exposades les principals característiques d'un ensenyament-aprenentatge inclusiu i les dimensions d’anàlisi del currículum ocult que pretenem observar. Tot seguit, fem constar la metodologia emprada per portar a terme la investigació i les graelles d’observació. Desprès d’aquestes hi ha un anàlisi i comparació de les escoles observades. En aquest anàlisi es pot observar com en totes les aules analitzades hi ha presents elements de currículum ocult que afavoreixen o dificulten la inclusió . dels infants. L’última part del treball són les conclusions on hi ha les principals idees sorgides després de l’elaboració del treball. A més, hi ha una petita reflexió sobre allò que s’hauria de millorar per crear aules realment inclusives on tots els nens i nenes tinguessin les mateixes oportunitats per adquirir un aprenentatge significatiu.The aim of this work is to see if there are elements of the hidden curriculum in three classrooms of Manresa and if they affect the inclusion and /or exclusion of students. To do it we have used a theoretical base where we have exposed the main features of an inclusive learning-education and the dimensions of the analysis that we intend to observe about the hidden curriculum. Then, there is the methodology that we have used to conduct the investigation and the observation girds. After that, there is an analysis and comparison of the observed schools. In the analysis we can see that it in all the classrooms we have found elements of hidden curriculum that promote or hinder inclusion and/or exclusion of the children. The last part of the work is the main ideas that emerged after we have finished it. In addition, there is a small reflection about what should be improved to create real inclusive classrooms where all children had the same opportunities to get a significant learning

On My Own: Acquiring Technical Digital Skills for Mobile Phone Use in Chile. Parents-children Perceptions

Despite its relevance, the difficulty in reaching consensus on the definition of digital competence slows down its implementation. The need of prior development of specific skills to advance in digital development has been recently reported. The acquisition of skills involves making the most of the opportunities offered by the digital environment. This article shows the results from a research conducted on 501 parent-child dyads in Chile in which minors aged 10 to 14 reported their self-perceptions on who (parents, siblings and peers) taught them certain technical and operational digital skills on mobile devices. Parents were also surveyed to know their perception about this children’s social mediation. Socio-demographic variables are also analysed. Chilean minors have a clear perception of autonomy in the acquisition of digital competence, parents underestimate their ability to influence, and other socialization agents such as siblings play a significant role. Age, gender and socioeconomic level to a lesser extent mark differences in the acquisition of these skills. In addition to providing a comparison on the perception parents and children have on the extent to which minors are accompanied while on their mobile phone, the article goes beyond parental mediation strategies and collects parental reflections on types of mediation