Collective intelligence: aggregation of information from neighbors in a guessing game

Complex systems show the capacity to aggregate information and to display coordinated activity. In the case of social systems the interaction of different individuals leads to the emergence of norms, trends in political positions, opinions, cultural traits, and even scientific progress. Examples of collective behavior can be observed in activities like the Wikipedia and Linux, where individuals aggregate their knowledge for the benefit of the community, and citizen science, where the potential of collectives to solve complex problems is exploited. Here, we conducted an online experiment to investigate the performance of a collective when solving a guessing problem in which each actor is endowed with partial information and placed as the nodes of an interaction network. We measure the performance of the collective in terms of the temporal evolution of the accuracy, finding no statistical difference in the performance for two classes of networks, regular lattices and random networks. We also determine that a Bayesian description captures the behavior pattern the individuals follow in aggregating information from neighbors to make decisions. In comparison with other simple decision models, the strategy followed by the players reveals a suboptimal performance of the collective. Our contribution provides the basis for the micro-macro connection between individual based descriptions and collective phenomena.Comment: 9 pages, 9 figure

The Endemism of the Vascular Flora of Mexico Present in Comarca Lagunera, an Agricultural Region in the Chihuahuan Desert

A study of the distribution of 321 taxa of endemic vascular plants of Mexico distributed in Comarca Lagunera, a region of northern central Mexico within the Chihuahuan Desert, was conducted. The analysis consisted in detecting the areas of high richness and with this information propose areas for the conservation of plant biodiversity in this region. The study includes an analysis of species richness at the level of political units (municipalities), vegetation types, and grid cells of 10 × 10 km. Additionally, the corrected weighted endemism index was calculated using the grid cells. The sites with the richest taxa are located in the mountain areas; however, these do not coincide with the sites with the highest index of endemism since a high percentage of taxa have a restricted distribution to one of the proposed units. Thirty-six taxa are recognized with restricted distribution to the boundaries of Comarca Lagunera, most of them considered as microendemics, which have been described in recent years. Therefore, it is necessary to establish biodiversity conservation programs in the region since much of Comarca Lagunera territory is dedicated to agricultural and industrial activities

Efecto de las condiciones de almacenamiento refrigerado sobre el estrés oxidativo en raquis de uva de mesa, cv. Red Globe

Indexación: Web of Science; ScieloTable grape (Vitis vinifera L.) quality includes the condition of both the berries and the rachis. In the present report, physiological parameters of Red Globe rachises from fully elongated inflorescences (RFEI) and from mature clusters were studied after storage at 0 or 20 °C for different durations. To understand changes in rachis physiology as a result of changes in temperature conditions and storage time, the activities of superoxide dismutase (SOD), catalase (CAT) and ascorbate peroxidase (APX) were measured. In addition, hydrogen peroxide content, membrane lipoperoxidation (TBARS), total phenolic compounds and antioxidant capacity (FRAP) were assayed. TBARS was higher in mature rachises than in RFEI. This parameter remained constant throughout storage, indicating a change presumably associated with ontogeny or senescence processes. Short-term storage (096 h) increased SOD, CAT and APX activities in RFEI, while in mature rachises, no changes were observed in enzyme activities or in hydrogen peroxide content. Longer cold storage (25 or 53 days at 0 °C) of mature rachises reduced CAT activity, but SOD and APX activities did not change under these conditions. At 0 h, the FRAP and total phenolic contents of mature rachises were three and 20 times higher than in immature rachises, respectively.La calidad de uva de mesa (Vitis vinifera L.) involucra tanto la condición de bayas y el raquis. En el presente trabajo, los parámetros fisiológicos de raquis de 'Red Globe' de inflorescencias completamente elongadas (RFEI) y de racimos maduros fueron estudiados después de almacenamientos por diferentes tiempos a 0 ó 20 °C. Para entender los cambios en la fisiología del raquis debido a variaciones de temperatura y condiciones de almacenamiento, se midieron las actividades de superoxido dismutasa (SOD), catalasa (CAT), ascorbato peroxidasa (APX). Además fueron analizados el contenido de peróxido de hidrógeno, lipoperoxidación de membranas (TBARS), compuestos fenólicos totales y capacidad antioxidante (FRAP). TBARS de los raquis maduros a la cosecha fue mayor que el de inflorescencias completamente elongadas (RFEI). Este parámetro permaneció constante a través del almacenamiento, indicando cambios presuntamente asociados a ontogenia o procesos de senescencia. Almacenamiento cortos (0-96h) incrementaron la actividad de SOD, CAT y APX en RFEI, sin embargo no se observaron cambios en la actividad de estas enzimas o contenido de peróxido de hidrogeno en raquis maduros. Almacenamiento refrigerado prolongado (25 ó 30 días 0 °C) de raquis maduros redujo la actividad de CAT, pero SOD y APX no mostraron cambios bajo estas condiciones. A 0 h el contenido de FRAP y fenólicos totales de raquis maduros fueron tres y 20 veces mayores que en raquis inmaduro respectivamente.http://ref.scielo.org/m3mg4

Eulàlia Pérez, presidenta de la FECYT

Eulàlia Pérez és, possiblement, una de les dones més actives de la ciència a Espanya. És vicepresidenta i cofundadora de AMIT (Associació de Dones Investigadores i Tecnòlogues), i ha realitzat i dirigit nombroses investigacions sobre ciència i valors, i sobre ciència, tecnologia i gènere. Al novembre, va intervenir al I Congrés Internacional "Biaix de gènere i desigualtats en l'avaluació de la qualitat acadèmica", que va organitzar l'Observatori per la Igualtat de la UAB, del 12 al 14 de novembre. En aquesta entrevista, repassem amb ella les bases de la desigualtat de gènere en l'àmbit de la ciència i la tecnologia i l'estat de la investigació a Espanya.Licenciada y doctora en Filosofía por la Universidad Autónoma de Madrid, es catedrática de Lógica y de Filosofía de la Ciencia de la Universidad del País Vasco y profesora de Ciencia, Tecnología y Género en el Instituto de Filosofía del CSIC. También ha sido profesora de la Universidad Complutense de Madrid, la Universidad de Barcelona, la Universidad de Cambridge (Reino Unido) y la Universidad de Berkeley (EEUU). Desde 2006 es directora de la Fundación Española para la Ciencia y la Tecnología (FECYT) del Ministerio de Educación y Ciencia. Eulalia Pérez intervino en el I Congreso Internacional "Sesgo de género y desigualdades en la evaluación de la calidad académica", que organizó del 12 al 14 de noviembre el Observatorio para la Igualdad de la UAB.A graduate in Philosophy and doctor of Philosophy from the Universitat Autònoma de Madrid, Eulalia Pèrez is professor of Logic and Philosophy of Science at the University of the Basque Country and lecturer in Science, Technology and Gender at the Institute of Philosophy of CSIC. She has also lectured at the Complutense University in Madrid, the University of Barcelona, the University of Cambridge (UK) and the University of Berkeley (USA). Since 2006 she has held the post of director of the Spanish Foundation for Science and Technology (FECYT) part of the Spanish Ministry of Education and Science. Eulàlia Pérez spoke at the First International Congress on "Gender bias and inequalities in the assessment of academic quality", which was organised by the UAB Observatory for Equality from 12 to 14 November 2007. In this interview, we review with her the basis of gender inequality in the field of science and technology

Improving the Statistical Qualities of Pseudo Random Number Generators

Pseudo random and true random sequence generators are important components in many scientific and technical fields, playing a fundamental role in the application of the Monte Carlo methods and stochastic simulation. Unfortunately, the quality of the sequences produced by these generators are not always ideal in terms of randomness for many applications. We present a new nonlinear filter design that improves the output sequences of common pseudo random generators in terms of statistical randomness. Taking inspiration from techniques employed in symmetric ciphers, it is based on four seed-dependent substitution boxes, an evolving internal state register, and the combination of different types of operations with the aim of diffusing nonrandom patterns in the input sequence. For statistical analysis we employ a custom initial battery of tests and well-regarded comprehensive packages such as TestU01 and PractRand. Analysis results show that our proposal achieves excellent randomness characteristics and can even transform nonrandom sources (such as a simple counter generator) into perfectly usable pseudo random sequences. Furthermore, performance is excellent while storage consumption is moderate, enabling its implementation in embedded or low power computational platforms.This research was funded by the Spanish Ministry of Science, Innovation and Universities (MCIU), the State Research Agency (AEI), and the European Regional Development Fund (ERDF) under project RTI2018-097263-B-I00 (ACTIS)

La economía de la dehesa y el desarrollo rural. La Sierra Morena sevillana

A long term strategy for development in a rural district located in Sierra Morena (Andalucía, Spain) is suggested. In this Mediterranean area, a great ecological, social and landscape diversity represents a «meeting point» among rural development politics, natural resources management and the economic activity of its population. The economic and social structure is still very traditional, where animal production (specially extensive pig production, with sheep, cattle and goats), olive growing and other forest resources such as hunting and cork industry are very important. There, large scale land ownership coexists with an important conservation area. Public policies and investment have a main influence in socio-economic dynamics of the population, who struggles among the necessary economic growth, the improvement of the quality of life and the conservation of those ecosystems that give this territory its originality and the best opportunities for the future.En el presente trabajo se sugiere una estrategia de desarrollo a largo plazo para la comarca de media montaña denominada Sierra Morena sevillana. En esta zona mediterránea, la gran diversidad ecológica, paisajística y social, supone un auténtico punto de conexión entre las políticas de desarrollo rural, la gestión de los recursos naturales y la actividad económica de sus habitantes. Se mantiene una estructura tradicional donde se combina el cultivo de secano (olivar), la ganadería extensiva o semiextensiva de cerdo ibérico con ovino, caprino y bovino, y otros aprovechamientos forestales como la caza y la transformación de corcho. La gran concentración de la propiedad de la tierra convive con la existencia de un importante espacio natural protegido bajo la figura de Parque Natural. En esta zona las políticas e inversiones públicas tienen un papel muy importante en la dinámica socioeconómica de una población que se debate entre el crecimiento económico, la mejora de la calidad de vida, y la conservación de aquellos ecosistemas que confieren al territorio su originalidad y son la base para su desarrollo económico futuro

Computational study of sail performance of a racing yacht

Es importante entender las caracteristicas del flujo y el comportamiento de las velas tanto para los navegantes como para los disenadores que quieren tener un empuje eficiente de la embarcacion. En este trabajo, se presenta la simulacion del flujo de aire alrededor de las velas, con una geometria final impuesta, y con un codigo CFD reproduciendo las medidas a escala real. El codigo numerico utilizado es un CFD viscoso basado en las ecuaciones RANS. Se han considerado tres combinaciones de velas: dos mayores y una mayor mas genova y los parametros estudiados principalmente son la sustentacion, resistencia, centro velico y el coeficiente de presion sobre las velas. Se han comparado los resultados obtenidos con datos experimentales y otros datos numericos procedentes de otros estudios. El estudio concluye que hay una buena concordancia entre los calculos numericos y los datos a escala real, mostrando la importancia de la utilizacion de estas herramientas numericas. It is important to understand flow characteristics and performance of sails for both sailors and designers who want to have an efficient thrust of yacht. In this article, the airflow around yacht sails with imposed final geometry is simulated using a CFD (Computational Fluid Dynamics) code reproducing full scale measurements. The code is a commercial viscous CFD based on Reynolds-averaged Navier-Stokes (RANS) equations. Three sets of sails are considered: two mainsails alone and one set of mainsail with jib and the parameters in study are mainly the lift, drag, center of effort and pressure coefficient over the sails. The results are compared with both experimental data and numerical computations obtained from other studies. It is concluded that there is good agreement between numerical calculations and full scale data, showing the importance of the use of numerical tools

"Organismos modificados genéticamente: del mundo a Cataluña"

Treball presentat a l'assignatura de Deontologia i Veterinària Legal (21223

Stability Criteria for Sailing Vessels

What do you know about sailing yacht stability? Which are the peculiarities of the stability of a sailing yacht? Is there any supposition different from those applied in conventional ships? If you have to verify the stability of your yacht, would you be sure of which criteria you should applied? The aim of this paper is to answer these questions among others. The authors assume that the readers of this paper come from varied backgrounds and experience. Some of you may not be totally familiar with these stability requirements whereas others may use them every day. It is hoped that this paper will be some enlightenment for the former and be an interesting review for the latter. In this paper the philosophy of sailing yacht stability will be presented. It will be also examined the criteria in force in countries such as Spain, United Kingdom, United States and The Netherlands among others and the assumptions upon which they are based will be highlighted. In order to clarify ideas two reference sailing yacht will be subjected to different criteria and compared their severity