Setting the Agenda: Different strategies of a Mass Media in a model of cultural dissemination

Day by day, people exchange opinions about a given new with relatives, friends, and coworkers. In most cases, they get informed about a given issue by reading newspapers, listening to the radio, or watching TV, i.e., through a Mass Media (MM). However, the importance of a given new can be stimulated by the Media by assigning newspaper's pages or time in TV programs. In this sense, we say that the Media has the power to "set the agenda", i.e., it decides which new is important and which is not. On the other hand, the Media can know people's concerns through, for instance, websites or blogs where they express their opinions, and then it can use this information in order to be more appealing to an increasing number of people. In this work, we study different scenarios in an agent-based model of cultural dissemination, in which a given Mass Media has a specific purpose: To set a particular topic of discussion and impose its point of view to as many social agents as it can. We model this by making the Media has a fixed feature, representing its point of view in the topic of discussion, while it tries to attract new consumers, by taking advantage of feedback mechanisms, represented by adaptive features. We explore different strategies that the Media can adopt in order to increase the affinity with potential consumers and then the probability to be successful in imposing this particular topic.Comment: 23 pages, 7 figure

Control visual basado en características de un sistema articulado. Estimación del jacobiano de la imagen utilizando múltiples vistas

En la presente tesis se aborda el control visual de un sistema de tres grados de libertad utilizando dos cámaras fijas débilmente calibradas. Se trabaja con un esquema de Control Basado en Imagen, y más específicamente en la estimación en línea del jacobiano de la imagen. Se proponen nuevos algoritmos de estimación del jacobiano de la imagen usando técnicas no iterativas. Estos nuevos algoritmos se basan en la deinición de un factor de fiabilidad que depende de los movimientos ya realizados en el espacio de las articulaciones y sus respectivos cambios en las características. Además, se incorporado en la estimación del jacobiano la información de la geometría epipolar, en la figura de la matriz fundamental. Los resultados de las pruebas llevadas a cabo tanto en tareas de posicionamiento como de seguimiento, y la comparación realizada con los métodos existentes en la bibliografía, demuestran que la incorporación de la geometría epipolar y el factor de fiabilidad en la estimación del jacobiano de la imagen, incrementa la robustez del sistema frente al ruido. Esta contrastación se ha extendido al jacobiano obtenido mediante un cálculo analítico, Se comprueba que con el método propuesto en la presente tesis se alcanzan las mismas prestaciones que el jacobiano analítico obtenido luego de un riguroso y delicado proceso de calibración de cámaras, calibración cinemática, transformación cámara-robot, jacobiano del robot, y reconstrucción tridimensional. Se verifica la conveniencia de este nuevo método al no depender de las mismas relaciones que el jacobiano analítico. Se presentan además, dos aplicaciones adicionales de control visual: En la primera de ellas, se describen dos métodos para estimar el jacobiano de la imagen a partir de líneas. En la segunda, se muestra un control visual de robots móviles, utilizando la estimación de la homografía entre un plano del robot y la imagen. The present thesis deals with the visual servoing of an articular system of 3 d.o.f. using two fixed and weakly calibrated cameras. The servoing architecture is Image Based Visual Servoing, and this work deals especifically whith the online estimation of the image Jacobian. New algorithms for the estimation of the imagen Jacobian with no iteratives techniques are proposed. These new algorithms are based on the definition of a reliability factor which depends on both movements already realized into the joint space and their respective feature changes. In addition to the reliability factor, information from the epipolar geometry standed for the fundamental matrix has been also incorporated in the estimation of the imagen Jacobian. Experiments have been carried out in both positioning tasks and following tasks. By comparison with the existing methods in the literature, it is showed that the incorporation of the epipolar geometry and the reliabilty factor in the estimation of the image Jacobian, increases robustness of the system against noise. Experiment contrasts have been extended to the analytic Jacobian. It is showed that the same performance of the analytic Jacobian is attained with the method proposed in the present thesis. It is well known that the analytic Jacobian is obtained after a severe and delicate work in camera calibration, cinematic calibration, camera-robot transformation, robot Jacobian, and 3D reconstruction. The convenience of the proposed method is proved since this method does not depend on the same relations as the analytic Jacobian. Furthermore two control visual aplications are presented. In the first one, two methods of estimation of the image Jacobian from lines are described. In the second one, a visual servoing of mobile robots using the estimation of the homography between a plane and the image is described

Early Cognitive/Social Deficits and Late Motor Phenotype in Conditional Wild-Type TDP-43 Transgenic Mice

Frontotemporal Dementia (FTD) and amyotrophic lateral sclerosis (ALS) are two neurodegenerative diseases associated to mislocalization and aggregation of TAR DNA-binding protein 43 (TDP-43). To investigate in depth the behavioral phenotype associated with this proteinopathy, we used as a model transgenic (Tg) mice conditionally overexpressing human wild-type TDP 43 protein (hTDP-43-WT) in forebrain neurons. We previously characterized these mice at the neuropathological level and found progressive neurodegeneration and other features that evoke human TDP-43 proteinopathies of the FTD/ALS spectrum. In the present study we analyzed the behavior of mice at multiple domains, including motor, social and cognitive performance. Our results indicate that young hTDP-43-WT Tg mice (1 month after post-weaning transgene induction) present a normal motor phenotype compared to control littermates, as assessed by accelerated rotarod performance, spontaneous locomotor activity in the open field test and a mild degree of spasticity shown by a clasping phenotype. Analysis of social and cognitive behavior showed a rapid installment of deficits in social interaction, working memory (Y-maze test) and recognition memory (novel object recognition test) in the absence of overt motor abnormalities. To investigate if the motor phenotype worsen with age, we analyzed the behavior of mice after long-term (up to 12 months) transgene induction. Our results reveal a decreased performance on the rotarod test and in the hanging wire test, indicating a motor phenotype that was absent in younger mice. In addition, long-term hTDP-43-WT expression led to hyperlocomotion in the open field test. In sum, these results demonstrate a time-dependent emergence of a motor phenotype in older hTDP-43-WT Tg mice, recapitulating aspects of clinical FTD presentations with motor involvement in human patients, and providing a complementary animal model for studying TDP-43 proteinopathies.Fil: Alfieri, Julio Armando. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Fisiología y Biofísica Bernardo Houssay. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Fisiología y Biofísica Bernardo Houssay; ArgentinaFil: Silva Pinto, Pablo Roberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Fisiología y Biofísica Bernardo Houssay. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Fisiología y Biofísica Bernardo Houssay; ArgentinaFil: Müller Igaz, Lionel Ivan. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Fisiología y Biofísica Bernardo Houssay. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Fisiología y Biofísica Bernardo Houssay; Argentin

Diagnóstico, tratamiento y seguimiento de la hidatidosis

ResumenEn el año 2003 el grupo de trabajo de la OMS sobre la equinococosis (WHO-IWGE) publicó una clasificación ecotomográfica que monitorea su historia natural. Esta se traduce en el paso de un quiste simple a una etapa de transición, la cual finaliza con su inactivación.Basándose en esta clasificación y ante la carencia de criterios uniformes en el manejo de esta enfermedad en el país, el grupo de trabajo de la región de Aysén decidió proponer un manejo integral de esta zoonosis, la cual fue aceptada y publicada como normas por el Ministerio de Salud en enero del 2016.El objetivo de este documento es dar a conocer las normas en el diagnóstico, tratamiento y seguimiento de los pacientes portadores de hidatidosis basado en las normas ministeriales.AbstractIn 2003 the Working Group on Echinococcosis WHO (WHO-IWGE) published a classification ecotomographic monitors its natural history. This results in the passage from a simple cyst to a transitional stage which ends with its inactivation.Based on this classification and in the absence of uniform criteria in the management of this disease in the country, it is that the working group of the Aysen Region decided to propose an integrated management of this zoonosis, which was accepted and published as Standards for the Ministry of Health in January 2016.The purpose of this paper is to present standards in the diagnosis, treatment and monitoring of patients with hydatid disease based on ministerial standards

Erdós-Rényi phase transition in the Axelrod model on complete graphs

The Axelrod model has been widely studied since its proposal for social influence and cultural dissemination. In particular, the community of statistical physics focused on the presence of a phase transition as a function of its two main parameters, F and Q. In this work, we show that the Axelrod model undergoes a second-order phase transition in the limit of F→∞ on a complete graph. This transition is equivalent to the Erdos-Rényi phase transition in random networks when it is described in terms of the probability of interaction at the initial state, which depends on a scaling relation between F and Q. We also found that this probability plays a key role in sparse topologies by collapsing the transition curves for different values of the parameter F.Fil: Pinto, Sebastián. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física de Buenos Aires; ArgentinaFil: Balenzuela, Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física de Buenos Aires; Argentin

A normative approach to intergroup contact: the role of ingroup norms regarding interactions with members of the outgroup

The main argument developed in this thesis is that individuals are not only affected by their own experiences of intergroup contact, but also by the contact they perceive is occurring around them. A pivotal reason for this is a change in the perception of ingroup norms regarding intergroup interactions, which can shape intergroup attitudes and make future positive intergroup contact experiences more likely. Chapter 1 provides a review of the literature of intergroup contact and makes the case for the necessity of a normative perspective on intergroup contact research. I Chapter 2, I provide a brief overview of the literature regarding the effect of social norms in intergroup relations, and describe in more detail the theoretical model proposed. Chapters 3 and 4 provide some initial evidence for the model using cross-sectional studies, showing that ingroup norms are associated with attitudes and with the intention of having intergroup contact, and that direct and indirect contact rely on different mechanisms to improve attitudes towards the outgroup. The effect of indirect contact is of a normative nature while the effect of direct contact is more emotional. Chapter 5 focuses on the distinction between ingroup norms about contact and ingroup norms about expressing prejudice, and the evaluation of moderators of the effect in ingroup norms. Chapter 6 reports two longitudinal studies, providing some evidence in support for a causal effect of ingroup norms about contact on several outcomes; and Chapter 7 reports a series of experiments, including results showing that ingroup norms predict the success of an actual interaction with outgroup members. In Chapter 8, I summarise the evidence for the theoretical model proposed and discuss some promising directions for future research, as well as the implications of these results for the reduction of segregation and the improvement of intergroup relations in general

A novel analytical formulation of the Axelrod model

The Axelrod model of cultural dissemination has been widely studied in the field of statistical mechanics. The traditional version of this agent-based model is to assign a cultural vector of $F$ components to each agent, where each component can take one of $Q$ cultural trait. In this work, we introduce a novel set of mean field master equations to describe the model for $F=2$ and $F=3$ in complete graphs where all indirect interactions are explicitly calculated. We find that the transition between different macroscopic states is driven by initial conditions (set by parameter $Q$) and the size of the system $N$, who measures the balance between linear and cubic terms in master equations. We also find that this analytical approach fully agrees with simulations where the system does not break up during the dynamics and a scaling relation related to missing links reestablishes the agreement when this happens

Juncus emmanuelis

This species is endemic to a small area in the southwestern Iberian Peninsula, with subpopulations scattered in approximately 16 localities. It is assessed as Endangered (EN B2ab(ii,iii,iv)) because it has an Area of Occupancy (AOO) of less than 500 km2 and shows signs of severe fragmentation due to the ongoing transformation of its specific habitat of sandy soils with an impermeable underlayer in temporary pools, as a result of several ongoing major threats associated with intensive agricultural activities. Based on this information, a continuing decline in the AOO, habitat quality and number of subpopulations has been inferred. Additional research and conservation action is needed for this species