Bruce Mazlish: The Fourth Discontinuity. The Co-Evolution of Humans and Machines. Yale University Press, New Haven y Londres, 1993

Sin resume

Los nuevos formatos de la imagen electrónica

Depto. de Ciencias de la Comunicación AplicadaFac. de Ciencias de la InformaciónTRUEpu

Biología reproductiva de la raya Rhinoptera bonasus (Elasmobranchii) en el sureste del Golfo de México

The cownose ray Rhinoptera bonasus is one of the most abundant batoid species in southeastern Gulf of Mexico, where it is occasionally caught and salt-dried for human consumption. To date, there are no estimates of the reproductive parameters which are needed to assess the dynamics of the local population of this species, and its vulnerability to fisheries. The analysis of 136 females with a size range of 43-106 cm disc width (DW) and 56 males with a size range of 43-93 cm DW, allowed to estimate that the lengths at maturity (DW50%) are 89.1 cm DW and 76.4 cm DW for females and for males, respectively. The female reproductive cycle is apparently biennial. The gestation lasts close to 12 months, gestation and vitellogenesis are consecutive, and ovulation and parturition occur from mid-March to mid-June. The results indicate a brood size of one and the lengths at birth ranged between 37.5 and 43 cm DW. Apparently, the sizes at maturity estimated for the southeastern and the northern Gulf of Mexico are different, because the data for the northern Gulf of Mexico indicate DW values of 65.3 and 64.2 cm for females and males, respectively. The biennial reproductive cycle of the southeastern Gulf of Mexico population seems different from that of the northwestern Atlantic, which is apparently annual.La raya Rhinoptera bonasus es uno de los batoideos más abundantes en el sureste del Golfo de México, en donde es capturada incidentalmente y procesada seca-salada para consumo humano. En esta región, a la fecha no existen estimaciones de los parámetros reproductivos necesarios para conocer su dinámica poblacional y evaluar su vulnerabilidad a la pesca por medio de análisis demográficos o evaluaciones de riesgo ecológico. Del análisis de 136 hembras con un intervalo de longitud de 43-106 cm de ancho de disco (AD) y 56 machos con un intervalo de longitud de 43-93 cm AD, se estimó una longitud de madurez (AD50%) de 89.1 cm y 76.4 cm AD para hembras y machos respectivamente. El ciclo reproductivo de las hembras es aparentemente bienal, con una gestación de 12 meses; la gestación y la vitelogénesis son consecutivas. La ovulación y el alumbramiento ocurren de mediados de marzo a mediados de junio. La fecundidad fue de un embrión y la longitud de nacimiento de 37.5-43 cm AD. La longitud de madurez es diferente entre el sureste y el norte del Golfo de México; en el norte del Golfo es de 65.3 y 64.2 cm AD para hembras y machos, respectivamente. Al parecer también es diferente el ciclo reproductivo entre las poblaciones del sureste del Golfo de México (bienal) y el Atlántico noroeste (anual)

Violencia y miedo en los medios de comunicación. La paradoja del bombero pirómano

An essay on the relationship between the media and violence in todayʼs society. An analysis on the links among violent content in television programming and other forms of media entertainment and the levels of social alarm and the perception of shared fears. The article wonders about the current context of information overload and of media ubiquity and the new forms of electronic entertainment and its incidence in the social behaviour of children, youngsters and adults.  Una reflexión sobre la relación entre los medios de comunicación y la violencia en la sociedad actual. Análisis del vínculo entre los contenidos violentos de la programación televisiva y otras formas de entretenimiento mediático y los niveles de alarma social y de percepción del miedo colectivo. Se cuestionan el actual contexto de saturación informativa y de ubicuidad mediática y las nuevas formas de ocio electrónico y su repercusión en los comportamientos sociales de niños, jóvenes y adultos. &nbsp

Los nuevos formatos de la imagen electrónica

Depto. de Ciencias de la Comunicación AplicadaFac. de Ciencias de la InformaciónTRUEpu

Del sueño a la pesadilla : la imagen de fin de siglo

Images are flooding our lifes, driving our behavior, substituting our dreams. The new electronic fantasies are made in America and exported to the rest of the world: from the role of the family to that of the woman, from sexual relationships to violent acts, everything finds its reflection in film and television. But what was first. reality or show? Who establishes the rules and who is responsible of what we watch? Audiovisual culture is the main vehicle of communication and transmission and it is not receiving enough attention from scholars and education. The media absorve the functions of art, religion and ideologies to give back a turmoil of segmented icons that everyone tries to interpret individually with very little help

Extracting dimer structures from simulations of organic-based materials using QM/MM methods

The functionality of weakly bound organic materials, either in Nanoelectronics or in Materials Science, is known to be strongly affected by their morphology. Theoretical predictions of the underlying structure–property relationships are frequently based on calculations performed on isolated dimers, but the optimized structure of the latter may significantly differ from experimental data even when dispersion-corrected methods are used for it. Here, we address this problem on two organic crystals, namely coronene and 5,6,11,12-tetrachlorotetracene, concluding that it is caused by the absence of the surrounding monomers present in the crystal, and that it can be efficiently cured when the dimer is embedded into a general Quantum Mechanics/Molecular Mechanics (QM/MM) geometry optimization scheme. We also investigate how the size of the MM region affects the results. These findings may be helpful for the simulation of the morphology of active materials in crystalline or glassy samples.This work is supported by the “Ministerio de Economía y Competitividad” of Spain and the “European Regional Development Fund” through project CTQ2014–55073-P

Theoretical study of stability and charge-transport properties of coronene molecule and some of its halogenated derivatives: A path to ambipolar organic-based materials?

We have carefully investigated the structural and electronic properties of coronene and some of its fluorinated and chlorinated derivatives, including full periphery substitution, as well as the preferred orientation of the non-covalent dimer structures subsequently formed. We have paid particular attention to a set of methodological details, to first obtain single-molecule magnitudes as accurately as possible, including next the use of modern dispersion-corrected methods to tackle the corresponding non-covalently bound dimers. Generally speaking, this class of compounds is expected to self-assembly in neighboring π-stacks with dimer stabilization energies ranging from –20 to –30 kcal mol−1 at close distances around 3.0–3.3 Å. Then, in a further step, we have also calculated hole and electron transfer rates of some suitable candidates for ambipolar materials, and corresponding charge mobility values, which are known to critically depend on the supramolecular organization of the samples. For coronene and per-fluorinated coronene, we have found high values for their hopping rates, although slightly smaller for the latter due to an increase (decrease) of the reorganization energies (electronic couplings).This work is supported by the “Ministerio de Educación y Ciencia” of Spain and the “European Regional Development Fund” through Project No. CTQ2011-27253

Theoretical Insights for Materials Properties of Cyclic Organic Nanorings

The synthesis of new carbon nanoforms with remarkable and fine‐tuned bulk properties still represents a formidable challenge, with cyclic organic nanorings emerging in recent years for the template‐driven design of this kind of systems. The design and engineering of these materials can be first controlled at the molecular scale, to further induce their specific self‐assembly toward tailored properties at the nanoscale. Theoretical studies have lately contributed to the understanding of the underlying physical effects, the development of synthetic strategies, and the rationalization of novel materials properties, employing a variety of methods ranging from accurate calculations of isolated molecules to atomistic molecular dynamics simulations of a large sample of molecules in realistic conditions, which will be reviewed here with a focus on the transition from single‐molecule to supramolecular properties.Computational resources were provided along the years by projects CTQ2014-55073-P and PID2019-106114GB-I00 (“Ministerio de Ciencia e Innovación”) and AICO/2018/175 (“Generalitat Valenciana”)

On the Relationships of Postcanine Tooth Size with Dietary Quality and Brain Volume in Primates: Implications for Hominin Evolution

Brain volume and cheek-tooth size have traditionally been considered as two traits that show opposite evolutionary trends during the evolution of Homo. As a result, differences in encephalization and molarization among hominins tend to be interpreted in paleobiological grounds, because both traits were presumably linked to the dietary quality of extinct species. Here we show that there is an essential difference between the genus Homo and the living primate species, because postcanine tooth size and brain volume are related to negative allometry in primates and show an inverse relationship in Homo. However, when size effects are removed, the negative relationship between encephalization and molarization holds only for platyrrhines and the genus Homo. In addition, there is no general trend for the relationship between postcanine tooth size and dietary quality among the living primates. If size and phylogeny effects are both removed, this relationship vanishes in many taxonomic groups. As a result, the suggestion that the presence of well-developed postcanine teeth in extinct hominins should be indicative of a poor-quality diet cannot be generalized to all extant and extinct primates.This research has been funded by the Spanish Ministry of Science and Innovation (Projects CGL2010-18124, CGL2011-30334, and HAR2008-04577) and supported by the Department of Economy, Innovation and Science, Junta de Andalucía, Spain (Project P11-HUM-7248 and Research Groups HUM-607 and RNM-146)