Subject-specific Performance Information can worsen the Tragedy of the Commons: Experimental Evidence

The main aim of this article is to investigate the behavioral consequences of the provision of subject-specific information in the group effort levels chosen by players in an experimental CPR game. We examine two basic treatments, one with incomplete information and the other with complete information. In the former, subjects are informed only about their own individual payoffs and the aggregate extraction effort level of the group, and in the latter they are also informed about the individual effort levels and payoffs of each subject. Given this setting, the basic question we attempt to answer is: Will the provision of subject-specific performance information (i.e. individual’s effort levels and payoffs) improve or worsen the tragedy of the commons (i.e. an exploitation effort level greater than the socially optimum level)? In order to motivate our hypotheses and explain our experimental results at the individual level, we make use of the theory of learning in games, which goes beyond standard non-cooperative game theory, allowing us to explore the three basic benchmarks in the commons context: Nash equilibrium, Pareto efficient, and open access outcomes. We use several learning and imitation theoretical models that are based on contrasting assumptions about the level of rationality and the information available to subjects, namely: best response, imitate the average, mix of best response and imitate the average, imitate the best and follow the exemplary learning rules. Finally, in order to econometrically test the hypotheses formulated from the theoretical predictions we use a random-effects model to assess the explanatory power of the different selected behavioral learning and imitation rules.Common Property Resources, Information, Learning and Imitation, Experimental Economics.

La tecno-comunicación: una moneda de tres lados

El presente artículo pretende dar cuenta del fenómeno de la ‘experiencias mediáticas’ que nos proporcionan los medios de comunicación social y las nuevas tecnologías

Combined use of SAR and scatterometer for the study of the atmospheric boundary layer

The paper illustrates a possible way of combining SAR images over the sea with scatterometer derived wind fields, to study the spatial characteristics of the marine atmospheric boundary layer (MABL). Both instruments are active microwave radars, relying upon the same physical mechanisms of electromagnetic wave-sea surface interaction. Sensing the sea surface with different spatial resolutions, they make possible to investigate the horizontal and vertical structure of the MABL from the mesoscale (< 100 km) down to the intermediate (< 10 km) and small (< 2 km) scales. An example of the multi-scale description of the MABL is provided analysing overlapping SAR image and scatterometer wind field in the Mediterranean Sea. Environmental conditions of this case study were characterised by moderate wind (8 to 10 m s −1) and unstable air-sea conditions. The radar backscatter modulations exhibited by the SAR image reveal the presence of largescale atmospheric variations, orographic wind distortions and wind rolls. The majority of the large-scale modulations of radar backscatter are obviously related to the wind speed;some other large-scale feature, which does not seem directly related to the wind, could be explained by the weak Ekman vertical velocity, derived from the scatterometer wind field. The analyses of the wind rolls have been performed through the bi-dimensional spectrum of the SAR image, which shows a two-scale orthogonal wave system with wavelengths of 7 km and 1.5 km. The paper points out the importance of other parameters, such as the sea and air temperatures, in the interpretation of the SAR images and in the full exploitation of the scatterometer winds

Wavelet analysis applied to SAR images to detect atmospheric structures

The aim of this work is to evaluate the possibilities offered by the wavelet analysis in the study of the spatial structure of the radar backscatter, which is linked to the spatial structure of the marine atmospheric boundary layer. Continuous wavelet analysis has been applied to a SAR image of the sea surface, previously analysed by the more classical Conditional Sampling technique. The main problem coped with has been to select, among the large number of wavelet maps produced by the analysis (256), those containing the more energetic backscatter structures. Since the phenomenon imaged by SAR was the convective turbulence, a multiscale and quasi-periodic or intermittent process, a selection of wavelet maps according to their mean energy was unsuccessful. On the contrary, a method based on the calculation of the standard deviation of the less probable highest wavelet amplitudes led to a right selection of the wavelet maps and to a convincing reconstruction of the map of backscatter structures, which resulted similar to that provided through the Conditional Sampling

Far Proximal and Far Distal Tibial Fractures: Management with Intramedullary Nails

Operative treatment of tibial fractures located at the proximal metaphyseal-epiphyseal and distal metaphyseal-epiphyseal areas, including those with articular extensions, is a technical challenge. Common methods for surgical management include plates (locking and nonlocking), external fixation devices, and intramedullary nails. All these methods have shown satisfactory results in terms of quality of reduction and clinical and radiological outcomes. The authors present some technical methods and strategies that have been useful for the surgical approach, reduction, and fixation of these lesions with the use of locked nails

El persistente impulso a resemantizar

Los lenguajes humanos fueron inventados para "semantizar la realidad", esto es, para expresar los contenidos y sentidos del mundo por medio de alguna forma codificada. ¿Semantizar' viene del término griego  ¿¿¿¿¿¿¿¿¿¿  y designa la significación de las palabras. De modo más amplio, la semántica (parte de la semiótica) estudia y analiza los procesos de significación de los signos, textos y discursos que circulan diacrónica y sincrónicamente por la sociedad. El uso de la palabra "resemantizar" está relacionado con la anterior, pero indica un proceso inverso, porque busca dar realce a un sentido ya existente, o a uno nuevo recuperado, ya sea en forma total o parcial. Como en otros numerosos términos, el prefijo "re" tiene el sentido de volver a poner algo, de añadir algo a una cosa anterior, o bien, alude a un efecto que trasciende una obra original. Pensemos en palabras como "re-fundar", "re-presentar", "re-producir", "re-percutir", "reposicionar, re-organizar", "re-equilibrar, re-pintar", entre otras. Todas estas palabras indican una variedad de acciones cuyo elemento común consiste en indicar la acción de añadir, desarrollar, construir, a partir de un fundamento existente. La tarea de resemantizar arranca, entonces, de un sentido dado de antemano, y su objeto es expresar una nueva configuración. Se trata de una acción que puede tener pretensiones diversas. A veces se instala por la pérdida de contenidos semánticos de un determinado lenguaje; otras, tiene el fin de recuperar una degradación simbólica o mítica, o es un intento de innovación creativa.       En conclusión, resemantizar es un vocablo que se refiere a la operación semiótica de transformar el sentido de una realidad conocida o aceptada para renovarla o para hacer una transposición de modelo, creando una entidad distinta, pero con alguna conexión referencial con aquélla, de modo que esta última asume un nuevo significado que la primera no tenía. Vemos que la resemantización mezcla o integra aspectos de la analogía, de la metáfora y de la polisemia, ensamblándolos con el propósito de hacer algo novedoso. De la analogía se apodera del analogatum princeps; es decir, de la obra inspiradora y que contiene una cosmovisión o perspectiva que da lugar a una experiencia básica del mundo. El analogado principal es la raíz o punto de partida asumido intelectualmente. La metáfora, en cambio, en la resemantización se usa como un instrumento metodológico para la creación de la nueva obra. ¿Cómo acontece este fenómeno de resemantización