Juan V. Echagüe - Academia.edu (original) (raw)
Papers in Neurosciences by Juan V. Echagüe
ABSTRACT Static and dynamic measurements of the righting reflex were performed in intact toads (B... more ABSTRACT Static and dynamic measurements of the righting reflex were performed in intact toads (Bufo arenarum platensis) and at different stages of recovery from hemilabyrinthectomy. Reflex activity was evaluated by the toad's capacity to maintain a horizontal head position while rolled sideways. Static data were obtained from frontal photographs. In dynamic experiments platform position (stimulus) was measured through a potentiometer, while a linear accelerometer glued to the cranium was used to record head tilts. The dynamic study included a linear systems analysis using sinusoids of 0.5-3 Hz with rolls of up to 30° to each side. Hemilabyrinthectomy produced a head tilt towards the lesioned side, and gain decay and phase lag increase in the dynamic response. All postural defects recovered progressively within 30-60 days as already described in other species. Nevertheless, the tonic head deviation produced by dynamic stimuli of frequencies above 1 Hz did not recover. This remnant defect has not been observed in previous studies in which only static observations were performed. The involvement of a frequency-dependent rectifying mechanism in postural compensation is discussed.
Journal of Comparative Physiology A, 1989
Computer Methods and Programs in Biomedicine, 1989
A program for neuronal activity analysis is described. The applied computational techniques are s... more A program for neuronal activity analysis is described. The applied computational techniques are standard in the field of digital processing, but the program is particular in its field of application and mode of data selection. The program, written in Turbo Pascal for ,he IBM-PC and compatibles, statistically compares (Mann-Whitney U-test) two sets of graphically selected data, and establishes whether there are significant differences between them. Although the program was developed for spike frequency analysis, it can easily be adapted to perform statistical analysis of other kinds of data.
Papers by Juan V. Echagüe
Journal of Comparative Physiology A, 1989
SummaryThe electric organ (EO) ofGymnotus carapo was studied using different neurohistological te... more SummaryThe electric organ (EO) ofGymnotus carapo was studied using different neurohistological techniques including conventional electron microscopy. The electric tissue extends along the fish body from the pectoral girdle to the tip of the tail, constituting a single, undivided organ. However, taking into account the number, arrangement, and innervation of the electrocytes, it is possible to divide the EO into three different portions. The more rostral portion is included within the ventral wall of the abdominal cavity. It consists of singly and doubly innervated electrocytes arranged in two rows at each side of the midline. Innervation of this zone is supplied by the first 5–7 segmental nerves and by the ‘anterior electromotor nerves.’ Segmental nerves terminate on the rostral faces of doubly innervated electrocytes; axons stemming from the anterior electromotor nerves end on the caudal faces of both doubly and singly innervated electrocytes. There is an intermediate body-tail region in which the electrocytes are arranged in four dorsoventral tubes (tubes 1 to 4) on each side of the midline. In this zone, doubly innervated electrocytes (confined within tube 1) coexist together with singly innervated ones, receiving nerve terminals on their caudal faces (tubes 2, 3, and 4). The innervation characteristics appear modified at more distal portions of the tail where the doubly innervated electrocytes of tube 1 are replaced by singly innervated units. The most distal portion of the EO (approximately its terminal 30%) consists of numerous, homogeneously innervated electrocytes with nerve endings distributed exclusively on their caudal faces. Nerve supply to the intermediate and distal regions derives from the posterior electromotor nerves (PENs) which appear as well-defined anatomical entities beyond the level of metamere XXVII. At the bodytail and more distal regions the innervation pattern of the EO is particularly complex. Thin nerve trunks arise from the PENs and project ventrally toward the electrocyte tubes. Before reaching the electric tissue the electromotor axons branch frequently. Our anatomical studies indicate that the EO is heterogeneous, a feature consistent with most recent electrophysiological and biophysical experiments.
We show how to use a wide class of Structural Operational Semantics specifications for Truly Conc... more We show how to use a wide class of Structural Operational Semantics specifications for Truly Concurrent Semantics, whereas the classical approach is rather based on interleaving models. The models we consider are Asynchronous Transition Systems and their behaviors are defined by means of a classical truly concurrent bisimulation : ST-bisimulation. However, the definition of ST-bisimulation over Asynchronous Transition Systems is new and makes this equivalence better understood. Moreover, we explain how our result holds of many other truly concurrent bisimulations of the literature. Introduction Plotkin has clearly formalized the technics of Structural Operational Semantics specification as a general method for defining semantics of programming languages [Plo81]. Milner [Mil81], [Mil89] introduced his calculus, CCS, by using this approach. Next, Groote and Vaandrager in [GV89], [Gro90] have considerably enriched the field by deriving transition systems [Kel76] modulo strong bisim...
Computer Methods and Programs in Biomedicine, 1989
En un equipo de desarrollo, los roles y funciones suelen estar definidos en base al objetivo pred... more En un equipo de desarrollo, los roles y funciones suelen estar definidos en base al objetivo predefinido. Por el contrario, en un equipo de investigación, son los conocimientos del equipo y los resultados los que definen qué hacer o hacia dónde ir. En este trabajo, reportamos la experiencia de vinculación, en un proyecto de I+D+i, llevado adelante entre Pragma Consultores y el LaFHIS de UBA. En esta vinculación, en el transcurso del proyecto, los roles y la dinámica dentro del equipo conjunto se ha adaptado siguiendo las necesidades puntuales, y aprovechando los conocimientos y respetando los tiempos de los integrantes. Una planificación flexible y el compromiso de los integrantes, han logrado que esta dinámica impulse el proyecto tomando, por un camino no planeado inicialmente, lo mejor de cada uno de los ambientes: industrial y académico.
The State and its citizens generate lots of data. Once stored and processed, data can help resolv... more The State and its citizens generate lots of data. Once stored and processed, data can help resolve questions in Social Sciences, where it is common to need data in a different level of aggregation than the data is presented. In election results, we would like to understand the decision of each voter or group of voters, but the data is only available at the polling-place level. This problem is known as ecological inference. In this work we compare two methods to estimate the share of votes for each party according to different age groups. This work is complemented with the analysis of votes between the first and second rounds, as well as a referendum during the first. This analysis was performed on the 2014 uruguayan presidential elections.
In this article we present the results of a data analysis project for a public-transport company.... more In this article we present the results of a data analysis project for a public-transport company. This project encompassed data preparation, analysis and visualization of three years of historical data. The data consisted in ticket purchases and GPS location of the vehicles. This work describes the project from start to end, including the incorporation of the results in the business process.
Big Bang Data en Transporte. Cómo Big Data puede ensamblar soluciones de ingeniería en transporte con la gestión sociotécnica de la movilidad en la ciudad
En un equipo de desarrollo, los roles y funciones suelen estar definidos en base al objetivo pred... more En un equipo de desarrollo, los roles y funciones suelen estar definidos en base al objetivo predefinido. Por el contrario, en un equipo de investigación, son los conocimientos del equipo y los resultados los que definen qué hacer o hacia dónde ir. En este trabajo, reportamos la experiencia de vinculación, en un proyecto de I+D+i, llevado adelante entre Pragma Consultores y el LaFHIS de UBA. En esta vinculación, en el transcurso del proyecto, los roles y la dinámica dentro del equipo conjunto se ha adaptado siguiendo las necesidades puntuales, y aprovechando los conocimientos y respetando los tiempos de los integrantes. Una planificación flexible y el compromiso de los integrantes, han logrado que esta dinámica impulse el proyecto tomando, por un camino no planeado inicialmente, lo mejor de cada uno de los ambientes: industrial y académico.
El Estado, como organizador de la Sociedad, y sus ciudadanos generan enormes cantidades de datos.... more El Estado, como organizador de la Sociedad, y sus ciudadanos generan enormes cantidades de datos. ´Estos, una vez almacenados y procesados, pueden dar soporte a inquietudes de ramas de las Ciencias Sociales, donde es frecuente encontrarnos con el problema de razonar sobre unidades de ana´lisis diferentes a aquellas sobre las que tenemos datos. En las votaciones, podr´ıamos querer entender la decisio´n de cada elector o de grupos de electores, cuando inicialmente disponemos so´lo de informacio´n sobre los resultados agrupados por mesa. El problema de estimar valores para una unidad utilizando valores de la otra se conoce como inferencia ecolo´gica. En este trabajo, comparamos dos m´etodos para estimar el porcentaje de votos para cada partido, en base a la franja etaria del electorado. El trabajo se complementa con ana´lisis de variacio´n entre votos de primera y de segunda vuelta, y de un plebiscito independiente durante la primera vuelta. Realizamos nuestro ana´lisis utilizando resultados de elecciones nacionales de 2014 en Uruguay.
Papers in Computer Science by Juan V. Echagüe
We show h o w to use a wide class of Structural Operational Semantics speci cations for Truly Con... more We show h o w to use a wide class of Structural Operational Semantics speci cations for Truly Concurrent Semantics, whereas the classical approach is rather based on interleaving models. The models we consider are Asynchronous Transition Systems and their behaviors are de ned by means of a classical truly concurrent bisimulation : ST-bisimulation. However, the de nition of ST-bisimulation over Asynchronous Transition Systems is new and makes this equivalence better understood. Moreover, we explain how our result holds of many other truly concurrent bisimulations of the literature.
Syntactic formats of SOS specifications as a criterion to obtain compositional semantics have wid... more Syntactic formats of SOS specifications as a criterion to obtain compositional semantics have widely been investigated, almost always in the interleaving setting. In this paper, we study the case of truly concurrent semantics. We show how to derive Asynchronous Transition Systems with invisible actions from SOS specifications, and we exhibit simple syntactic conditions over the specifications to get compositionality for (rooted) ST-semantics. Classical process description languages like CCS fit the conditions.
Dans cette thèse, nous étudions les systèmes de transitions asynchrones en tant que modèles pour ... more Dans cette thèse, nous étudions les systèmes de transitions asynchrones en tant que modèles pour la sémantique des systèmes réactifs. Les systèmes de transitions asynchrones (STA) de Shields et Bednarczyk, sont une généralisation des systèmes de transitions (ST) et des structures d'événements stables (SE). Tout d'abord nous définissons l'opération de raffinement d'actions sur les STA, qui permet de relier entre elles les descriptions d'un système a différents niveaux d'abstraction. Ensuite, nous proposons des équivalences sémantiques sur les STA et nous étudions leur compatibilité avec l'opération de raffinement. Enfin, nous relions notre cadre avec celui de la théorie des sémantiques opérationnelles structurées (SOS) de Plotkin
fing.edu.uy
Page 1. From Semantics into Spatial Distribution Pedro R. D'Argenio1y , Juan V. Echag ue2, a... more Page 1. From Semantics into Spatial Distribution Pedro R. D'Argenio1y , Juan V. Echag ue2, and Luis R. Sierra Abbate2. 1 Dept. of Computer Science. University of Twente. POBox 217. 7500 AE Enschede. The Netherlands. dargenio@cs.utwente.nl 2 Instituto de Computaci on. ...
Lecture Notes in Computer Science, 2000
We show how to use a wide class of Structural Operational Semantics specifications for Truly Conc... more We show how to use a wide class of Structural Operational Semantics specifications for Truly Concurrent Semantics, whereas the classical approach is rather based on interleaving models. The models we consider are Asynchronous Transition Systems and their behaviors are defined by means of a classical truly concurrent bisimulation : ST-bisimulation. However, the definition of ST-bisimulation over Asynchronous Transition Systems is new and makes this equivalence better understood. Moreover, we explain how our result holds of many other truly concurrent bisimulations of the literature.
ABSTRACT Static and dynamic measurements of the righting reflex were performed in intact toads (B... more ABSTRACT Static and dynamic measurements of the righting reflex were performed in intact toads (Bufo arenarum platensis) and at different stages of recovery from hemilabyrinthectomy. Reflex activity was evaluated by the toad's capacity to maintain a horizontal head position while rolled sideways. Static data were obtained from frontal photographs. In dynamic experiments platform position (stimulus) was measured through a potentiometer, while a linear accelerometer glued to the cranium was used to record head tilts. The dynamic study included a linear systems analysis using sinusoids of 0.5-3 Hz with rolls of up to 30° to each side. Hemilabyrinthectomy produced a head tilt towards the lesioned side, and gain decay and phase lag increase in the dynamic response. All postural defects recovered progressively within 30-60 days as already described in other species. Nevertheless, the tonic head deviation produced by dynamic stimuli of frequencies above 1 Hz did not recover. This remnant defect has not been observed in previous studies in which only static observations were performed. The involvement of a frequency-dependent rectifying mechanism in postural compensation is discussed.
Journal of Comparative Physiology A, 1989
Computer Methods and Programs in Biomedicine, 1989
A program for neuronal activity analysis is described. The applied computational techniques are s... more A program for neuronal activity analysis is described. The applied computational techniques are standard in the field of digital processing, but the program is particular in its field of application and mode of data selection. The program, written in Turbo Pascal for ,he IBM-PC and compatibles, statistically compares (Mann-Whitney U-test) two sets of graphically selected data, and establishes whether there are significant differences between them. Although the program was developed for spike frequency analysis, it can easily be adapted to perform statistical analysis of other kinds of data.
Journal of Comparative Physiology A, 1989
SummaryThe electric organ (EO) ofGymnotus carapo was studied using different neurohistological te... more SummaryThe electric organ (EO) ofGymnotus carapo was studied using different neurohistological techniques including conventional electron microscopy. The electric tissue extends along the fish body from the pectoral girdle to the tip of the tail, constituting a single, undivided organ. However, taking into account the number, arrangement, and innervation of the electrocytes, it is possible to divide the EO into three different portions. The more rostral portion is included within the ventral wall of the abdominal cavity. It consists of singly and doubly innervated electrocytes arranged in two rows at each side of the midline. Innervation of this zone is supplied by the first 5–7 segmental nerves and by the ‘anterior electromotor nerves.’ Segmental nerves terminate on the rostral faces of doubly innervated electrocytes; axons stemming from the anterior electromotor nerves end on the caudal faces of both doubly and singly innervated electrocytes. There is an intermediate body-tail region in which the electrocytes are arranged in four dorsoventral tubes (tubes 1 to 4) on each side of the midline. In this zone, doubly innervated electrocytes (confined within tube 1) coexist together with singly innervated ones, receiving nerve terminals on their caudal faces (tubes 2, 3, and 4). The innervation characteristics appear modified at more distal portions of the tail where the doubly innervated electrocytes of tube 1 are replaced by singly innervated units. The most distal portion of the EO (approximately its terminal 30%) consists of numerous, homogeneously innervated electrocytes with nerve endings distributed exclusively on their caudal faces. Nerve supply to the intermediate and distal regions derives from the posterior electromotor nerves (PENs) which appear as well-defined anatomical entities beyond the level of metamere XXVII. At the bodytail and more distal regions the innervation pattern of the EO is particularly complex. Thin nerve trunks arise from the PENs and project ventrally toward the electrocyte tubes. Before reaching the electric tissue the electromotor axons branch frequently. Our anatomical studies indicate that the EO is heterogeneous, a feature consistent with most recent electrophysiological and biophysical experiments.
We show how to use a wide class of Structural Operational Semantics specifications for Truly Conc... more We show how to use a wide class of Structural Operational Semantics specifications for Truly Concurrent Semantics, whereas the classical approach is rather based on interleaving models. The models we consider are Asynchronous Transition Systems and their behaviors are defined by means of a classical truly concurrent bisimulation : ST-bisimulation. However, the definition of ST-bisimulation over Asynchronous Transition Systems is new and makes this equivalence better understood. Moreover, we explain how our result holds of many other truly concurrent bisimulations of the literature. Introduction Plotkin has clearly formalized the technics of Structural Operational Semantics specification as a general method for defining semantics of programming languages [Plo81]. Milner [Mil81], [Mil89] introduced his calculus, CCS, by using this approach. Next, Groote and Vaandrager in [GV89], [Gro90] have considerably enriched the field by deriving transition systems [Kel76] modulo strong bisim...
Computer Methods and Programs in Biomedicine, 1989
En un equipo de desarrollo, los roles y funciones suelen estar definidos en base al objetivo pred... more En un equipo de desarrollo, los roles y funciones suelen estar definidos en base al objetivo predefinido. Por el contrario, en un equipo de investigación, son los conocimientos del equipo y los resultados los que definen qué hacer o hacia dónde ir. En este trabajo, reportamos la experiencia de vinculación, en un proyecto de I+D+i, llevado adelante entre Pragma Consultores y el LaFHIS de UBA. En esta vinculación, en el transcurso del proyecto, los roles y la dinámica dentro del equipo conjunto se ha adaptado siguiendo las necesidades puntuales, y aprovechando los conocimientos y respetando los tiempos de los integrantes. Una planificación flexible y el compromiso de los integrantes, han logrado que esta dinámica impulse el proyecto tomando, por un camino no planeado inicialmente, lo mejor de cada uno de los ambientes: industrial y académico.
The State and its citizens generate lots of data. Once stored and processed, data can help resolv... more The State and its citizens generate lots of data. Once stored and processed, data can help resolve questions in Social Sciences, where it is common to need data in a different level of aggregation than the data is presented. In election results, we would like to understand the decision of each voter or group of voters, but the data is only available at the polling-place level. This problem is known as ecological inference. In this work we compare two methods to estimate the share of votes for each party according to different age groups. This work is complemented with the analysis of votes between the first and second rounds, as well as a referendum during the first. This analysis was performed on the 2014 uruguayan presidential elections.
In this article we present the results of a data analysis project for a public-transport company.... more In this article we present the results of a data analysis project for a public-transport company. This project encompassed data preparation, analysis and visualization of three years of historical data. The data consisted in ticket purchases and GPS location of the vehicles. This work describes the project from start to end, including the incorporation of the results in the business process.
Big Bang Data en Transporte. Cómo Big Data puede ensamblar soluciones de ingeniería en transporte con la gestión sociotécnica de la movilidad en la ciudad
En un equipo de desarrollo, los roles y funciones suelen estar definidos en base al objetivo pred... more En un equipo de desarrollo, los roles y funciones suelen estar definidos en base al objetivo predefinido. Por el contrario, en un equipo de investigación, son los conocimientos del equipo y los resultados los que definen qué hacer o hacia dónde ir. En este trabajo, reportamos la experiencia de vinculación, en un proyecto de I+D+i, llevado adelante entre Pragma Consultores y el LaFHIS de UBA. En esta vinculación, en el transcurso del proyecto, los roles y la dinámica dentro del equipo conjunto se ha adaptado siguiendo las necesidades puntuales, y aprovechando los conocimientos y respetando los tiempos de los integrantes. Una planificación flexible y el compromiso de los integrantes, han logrado que esta dinámica impulse el proyecto tomando, por un camino no planeado inicialmente, lo mejor de cada uno de los ambientes: industrial y académico.
El Estado, como organizador de la Sociedad, y sus ciudadanos generan enormes cantidades de datos.... more El Estado, como organizador de la Sociedad, y sus ciudadanos generan enormes cantidades de datos. ´Estos, una vez almacenados y procesados, pueden dar soporte a inquietudes de ramas de las Ciencias Sociales, donde es frecuente encontrarnos con el problema de razonar sobre unidades de ana´lisis diferentes a aquellas sobre las que tenemos datos. En las votaciones, podr´ıamos querer entender la decisio´n de cada elector o de grupos de electores, cuando inicialmente disponemos so´lo de informacio´n sobre los resultados agrupados por mesa. El problema de estimar valores para una unidad utilizando valores de la otra se conoce como inferencia ecolo´gica. En este trabajo, comparamos dos m´etodos para estimar el porcentaje de votos para cada partido, en base a la franja etaria del electorado. El trabajo se complementa con ana´lisis de variacio´n entre votos de primera y de segunda vuelta, y de un plebiscito independiente durante la primera vuelta. Realizamos nuestro ana´lisis utilizando resultados de elecciones nacionales de 2014 en Uruguay.
We show h o w to use a wide class of Structural Operational Semantics speci cations for Truly Con... more We show h o w to use a wide class of Structural Operational Semantics speci cations for Truly Concurrent Semantics, whereas the classical approach is rather based on interleaving models. The models we consider are Asynchronous Transition Systems and their behaviors are de ned by means of a classical truly concurrent bisimulation : ST-bisimulation. However, the de nition of ST-bisimulation over Asynchronous Transition Systems is new and makes this equivalence better understood. Moreover, we explain how our result holds of many other truly concurrent bisimulations of the literature.
Syntactic formats of SOS specifications as a criterion to obtain compositional semantics have wid... more Syntactic formats of SOS specifications as a criterion to obtain compositional semantics have widely been investigated, almost always in the interleaving setting. In this paper, we study the case of truly concurrent semantics. We show how to derive Asynchronous Transition Systems with invisible actions from SOS specifications, and we exhibit simple syntactic conditions over the specifications to get compositionality for (rooted) ST-semantics. Classical process description languages like CCS fit the conditions.
Dans cette thèse, nous étudions les systèmes de transitions asynchrones en tant que modèles pour ... more Dans cette thèse, nous étudions les systèmes de transitions asynchrones en tant que modèles pour la sémantique des systèmes réactifs. Les systèmes de transitions asynchrones (STA) de Shields et Bednarczyk, sont une généralisation des systèmes de transitions (ST) et des structures d'événements stables (SE). Tout d'abord nous définissons l'opération de raffinement d'actions sur les STA, qui permet de relier entre elles les descriptions d'un système a différents niveaux d'abstraction. Ensuite, nous proposons des équivalences sémantiques sur les STA et nous étudions leur compatibilité avec l'opération de raffinement. Enfin, nous relions notre cadre avec celui de la théorie des sémantiques opérationnelles structurées (SOS) de Plotkin
fing.edu.uy
Page 1. From Semantics into Spatial Distribution Pedro R. D'Argenio1y , Juan V. Echag ue2, a... more Page 1. From Semantics into Spatial Distribution Pedro R. D'Argenio1y , Juan V. Echag ue2, and Luis R. Sierra Abbate2. 1 Dept. of Computer Science. University of Twente. POBox 217. 7500 AE Enschede. The Netherlands. dargenio@cs.utwente.nl 2 Instituto de Computaci on. ...
Lecture Notes in Computer Science, 2000
We show how to use a wide class of Structural Operational Semantics specifications for Truly Conc... more We show how to use a wide class of Structural Operational Semantics specifications for Truly Concurrent Semantics, whereas the classical approach is rather based on interleaving models. The models we consider are Asynchronous Transition Systems and their behaviors are defined by means of a classical truly concurrent bisimulation : ST-bisimulation. However, the definition of ST-bisimulation over Asynchronous Transition Systems is new and makes this equivalence better understood. Moreover, we explain how our result holds of many other truly concurrent bisimulations of the literature.