Ordering dynamics in the voter model with aging

The voter model with memory-dependent dynamics is theoretically and numerically studied at the mean-field level. The `internal age', or time an individual spends holding the same state, is added to the set of binary states of the population, such that the probability of changing state (or activation probability $p_i$) depends on this age. A closed set of integro-differential equations describing the time evolution of the fraction of individuals with a given state and age is derived, and from it analytical results are obtained characterizing the behavior of the system close to the absorbing states. In general, different age-dependent activation probabilities have different effects on the dynamics. When the activation probability $p_i$ is an increasing function of the age $i$, the system reaches a steady state with coexistence of opinions. In the case of aging, with $p_i$ being a decreasing function, either the system reaches consensus or it gets trapped in a frozen state, depending on the value of $p_\infty$ (zero or not) and the velocity of $p_i$ approaching $p_\infty$. Moreover, when the system reaches consensus, the time ordering of the system can be exponential ($p_\infty>0$) or power-law like ($p_\infty=0$). Exact conditions for having one or another behavior, together with the equations and explicit expressions for the exponents, are provided

L'évolution des messages publicitaires des entreprises financières installées en Equateur : un indicateur de la mondialisation de la communication (1960-1991)

L'analyse des messages publicitaires insérés dans la presse écrite et télévisée par les institutions financières de 1960 à 1991 permet d'approcher l'influence socio-culturelle de ce secteur de l'économie sur les modes de vie des strates aisées et moyennes de la population équatorienne à partir de l'exemple quiténien. Si le message a vu son support évoluer depuis trois décennies (dessin dans les années soixante, photographie durant les années soixante-dix puis images de synthèse au cours des années quatre-vingt), son image projetée se caractérise par une relative continuité thématique. Toutefois, il semble que les campagnes publicitaires financières délaissent progressivement les éléments importés et intègrent ("récupèrent"?) des caractères régionaux ou nationaux. Enfin, si dans les années soixante le système financier avait recours à un langage spécifique, il s'oriente aujourd'hui vers l'utilisation de symboles et d'éléments écrits ou visuels qui sont tout à fait intégrés à la mondialisation de la communication. (Résumé d'auteur

An overview of structural aspects and health beneficial effects of antioxidant oligosaccharides

Background: Non-digestible oligosaccharides are versatile sources of chemical diversity, well known for their prebiotic actions, found naturally in plants or produced by chemical or enzymatic synthesis or by hydrolysis of polysaccharides. Compared to polyphenols or even polysaccharides, the antioxidant potential of oligosaccharides is still unexplored. The aim of the present work was to provide an up-to-date, broad and critical contribution on the topic of antioxidant oligosaccharides. Methods: The search was performed by crossing the words oligosaccharides and antioxidant. Whenever possible, attempts at establishing correlations between chemical structure and antioxidant activity were undertaken. Results: The most representative in vitro and in vivo studies were compiled in two tables. Chitooligosaccharides and xylooligosaccharides and their derivatives were the most studied up to now. The antioxidant activities of oligosaccharides depend on the degree of polymerization and the method used for depolymerization. Other factors influencing the antioxidant strength are solubility, monosaccharide composition, the type of glycosidic linkages of the side chains, molecular weight, reducing sugar content, the presence of phenolic groups such as ferulic acid, and the presence of uronic acid, among others. Modification of the antioxidant capacity of oligosaccharides has been achieved by adding diverse organic groups to their structures, thus increasing also the spectrum of potentially useful molecules. Conclusion: A great amount of high-quality evidence has been accumulating during the last decade in support of a meaningful antioxidant activity of oligosaccharides and derivatives. Ingestion of antioxidant oligosaccharides can be visualized as beneficial to human and animal health.This work was funded by the Conselho Nacional de Desenvolvimento Cientffico e Tecnológico (CNPq), Brazil; grants numbers 40898/2016-5 and 307944/2015-8).info:eu-repo/semantics/publishedVersio

Note on the Markus–Yamabe conjecture for gradient dynamical systems

AbstractLet v:Rn→Rn be a C1 vector field which has a singular point O and its linearization is asymptotically stable at every point of Rn. We say that the vector field v satisfies the Markus–Yamabe conjecture if the critical point O is a global attractor of the dynamical system x˙=v(x). In this note we prove that if v is a gradient vector field, i.e. v=∇f (f∈C2), then the basin of attraction of the critical point O is the whole Rn, thus implying the Markus–Yamabe conjecture for this class of vector fields. An analogous result for discrete dynamical systems of the form xm+1=∇f(xm) is proved

Deficiencia visual en el niño

La visión suministra una perspectiva global, simultánea y anticipadora del entorno. Un déficit severo de visión constituye un obstáculo para el adecuado desarrollo cognitivo y social del niño. La respuesta educativa a las necesidades prioritarias que la deficiencia visual genera, requiere una adecuada formación por parte de los profesionales: Para ello, es preciso que adquieran los conocimientos básicos relativos a la clasificación y el diagnóstico de la deficiencia visual, los aspectos esenciales del desarrollo y los fundamentos de la intervención educativa. El objetivo del presente trabajo es analizar las principales características de la deficiencia visual en los niños, y el impacto que dicha deficiencia tiene en el desarrollo y en el aprendizaje

Bibliometric analysis about university social responsibility

Se presenta un estudio descriptivo cuyo objetivo general fue conocer la producción científica sobre “Responsabilidad Social Universitaria” (RSU). Se realizó un análisis bibliométrico de 94 documentos obtenidos a través de las bases de datos Redalyc, Scielo y a través de la Biblioteca Electrónica de Ciencia y Tecnología del Ministerio de Ciencia, Tecnología e Innovación Productiva (Argentina). Los resultados mostraron que RSU es un campo de estudio reciente que comienza a tener visibilidad en las bases consideradas, el número de publicaciones ha aumentado a partir del año 2007. Venezuela, México, Colombia y Chile son los países que más documentos publicados acumulan. Cinco revistas se presentan como las más productivas. El 90% de los documentos analizados están firmados por un solo autor. No se han encontrado estudios bibliométricos previos en este tema.A descriptive study is presented which goal was to know about University Social Responsibility’s scientific production. A bibliometric analysis of 94 documents obtained from Redalyc and Scielo data bases and from Science and Technology Electronic Library from Science, Technology and Productive Innovation Ministry (Argentina) was carried out. Results showed that University Social Responsibility is a recently study area with newly visibility in considered bases, the number of publications has grown since 2007. Venezuela, Mexico, Colombia and Chile are the countries which present more published documents in the area. Five journals are the most productive. The 90% of the analyzed documents are signed by only one author. Bibliometric studies about this topic were not found.Fil: Pacenza, Maria Ines. Universidad Nacional de Mar del Plata. Facultad de Psicología; ArgentinaFil: Silva Peralta, Yamila Fernanda. Universidad Nacional de Mar del Plata. Facultad de Psicología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; Argentin

Linking diversity to organizational effectiveness: Lessons from a culture study at CIAT

This Brief describes a ‘culture study’ carried out to explore how different staff groups perceive the culture of an international research centre and how the management of staff diversity issues affects the work environment and organizational performance. The perceptions of various staff groups were analysed in relation to five aspects of organizational culture: institutional climate; global competitiveness; empowerment and group motivation; work–life balance; and equity in gender and diversity. The study identified what staff believed to be the key strengths and weaknesses in the organization’s culture and detected four strategic areas for improvement: internal organizational communications; re-design of job positions and responsibilities; multi-cultural competencies; and gender awareness in the workplace. The diagnostic process is described, as well as the follow-up actions taken to improve the management of gender and diversity in the centre