Conceptos: Desde la Filosofía de la mente a la Psicología Cognitiva

Concepto es una palabra que refiere a un constructo problemático en la psicología cognitiva y en la filosofía de la mente, el cual indistintamente refiere a cierto tipo de representaciones mentales, a entidades extramentales e incluso a habilidades psicológicas. Lo cierto es que las teorías de conceptos emblemáticas al interior de la filosofía y la psicología, como la Teoría Clásica de conceptos (entendidos como definiciones aristotélicas), o como la Teoría de Prototipos de Rosch (entendidos como estructuras estadísticas de datos), no logran dar cuenta de fenómenos tales como la productividad, la sistematicidad y la composicionalidad del pensamiento humano. Se analizarán los requisitos que una buena teoría psicológica sobre los conceptos debe satisfacer, y se presentará un breve esbozo de la Teoría de Sistemas de Símbolos Perceptuales de Lawrence Barsalou

Green IT, China – France: similar reactions?

Based upon a study carried out both in France and in China, this communication aims to answer the following question: Is it useful to invest in Green IT for Universities? This research provides information on the perception of individuals with respect to the label "green" placed on an IT object and also highlights the need to take into account the affective dimension of attitude in the Technology Acceptance Model. Our results may help in investment decisions regarding "green" technologyTechnology Acceptance Model, Green IT, intercultural study

Breadth-first search for social network graphs on heterogenous platforms

Breadth-First Search (BFS) is the core of many graph analysis algorithms, and it is useful in many problems including social network, computer network analysis, and data organization, but, due to its irregular behav- ior, its parallel implementation is very challenging. There are several approaches that implement efficient algorithms for BFS in multicore architectures and in Graphics Processors, but an efficient implementation of BFS for heterogeneous systems is even more complicated, as the task of distributing the work among the main cores and the accelerators becomes a big challenge. As part of this work, we have assessed different heterogenous shared-memory architectures (from high- end processors to embedded mobile processors, both composed by a multi-core CPU and an integrated GPU) and implemented different approaches to perform BFS. This work introduces three heterogeneous approaches for BFS: Selective, Concurrent, and Async. Contributions of this work includes both the analysis of BFS performance on Heterogenous platforms, as well as in depth analysis of social network graphs and its implications on the BFS algorithm. The results show that BFS is very input dependent, and that the structure of the graph is one of the prime factors to analyze in order to develop good and scalable algorithms. The results also show that heterogenous platforms can provide acceleration to even irregular algorithms, reaching speed-ups of 2.2x in the best case. It is also shown how the different system configurations and capabilities impact the performance and how the shared-memory system can reach bandwidth limitations that prevent performance improvements despite having higher utilization of the resources

Dynamics of genetic variability in Anastrepha fraterculus (Diptera: Tephritidae) during adaptation to laboratory rearing conditions

BACKGROUND: Anastrepha fraterculus is one of the most important fruit fly plagues in the American continent and only chemical control is applied in the field to diminish its population densities. A better understanding of the genetic variability during the introduction and adaptation of wild A. fraterculus populations to laboratory conditions is required for the development of stable and vigorous experimental colonies and mass-reared strains in support of successful Sterile Insect Technique (SIT) efforts. METHODS: The present study aims to analyze the dynamics of changes in genetic variability during the first six generations under artificial rearing conditions in two populations: a) a wild population recently introduced to laboratory culture, named TW and, b) a long-established control line, named CL. RESULTS: Results showed a declining tendency of genetic variability in TW. In CL, the relatively high values of genetic variability appear to be maintained across generations and could denote an intrinsic capacity to avoid the loss of genetic diversity in time. DISCUSSION: The impact of evolutionary forces on this species during the adaptation process as well as the best approach to choose strategies to introduce experimental and mass-reared A. fraterculus strains for SIT programs are discussed.Fil: Scannapieco, Alejandra Carla. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Genética; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Scannapieco, Alejandra Carla. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Genética; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Remis, Maria Isabel. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ecología, Genética y Evolución. Laboratorio de Genética de la Estructura Poblacional; ArgentinaFil: Juri, Marianela Lucia. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Genética; ArgentinaFil: Vera, María Teresa. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Tucumán. Facultad de Agronomía y Zootecnia. Cátedra Terapéutica Vegetal; ArgentinaFil: Segura, Diego Fernando. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Genética; ArgentinaFil: Cladera, Jorge Luis. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Genética; ArgentinaFil: Lanzavecchia, Silvia Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Genética; Argentin

Morphometric differentiation in Cornops Aquaticum (Orthoptera: Acrididae): associations with sex, chromosome, and geographic conditions

The water-hyacinth grasshopper Cornops aquaticum (Bruner) (Orthoptera: Acrididae) is native to South America and inhabits lowlands from southern Mexico to central Argentina and Uruguay. This grasshopper feeds and lays eggs on species from the genera Eichhornia and Pontederia. Particularly, Eichhornia crassipes is considered “the world’s worst water weed,” and the release of C. aquaticum was proposed as a form of biological control. Morphometric variation on the chromosomally differentiated populations from the middle and lower Parana´ River and its possible association with geographic, sex, and chromosomal conditions was analyzed. Significant phenotype variation in C. aquaticum population was detected. C. aquaticum presents body-size sexual dimorphism, females being bigger than males. Female-biased sexual size dimorphism for all five analyzed traits was detected. The assessment of variation in sexual size dimorphism for tegmen length showed that this trait scaled allometrically, indicating that males and females did not vary in a similar fashion. The detected allometry was consistent with Rensch’s rule demonstrating greater evolutionary divergence in male size than in female size and suggests that males are more sensitive to environmental condition. The analysis of morphometric variation in the context of chromosome constitution showed that the presence of fusion 1/6 was related to body-size variation. Fusion carriers displayed bigger body size than standard homozygotes. Besides, a positive relationship between tegmen length and the number of fused chromosomes was detected, showing a chromosome dose effect. Because the highest frequency of fusions has been found in the lower Parana´ River, a marginal environment for this species, the results found would support the hypothesis that some supergenes located in the fusions may be favored in the southern populations, thus contributing to the establishment and maintenance of the polymorphism.Fil: Romero, Maria Luciana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; ArgentinaFil: Colombo, Pablo Cesar. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; ArgentinaFil: Remis, Maria Isabel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; Argentin

Tamm states and nonlinear surface modes in photonic crystals

We predict the existence of surface gap modes, known as Tamm states for electronic systems, in truncated photonic crystals formed by two types of dielectric rods. We investigate the energy threshold, dispersion, and modal symmetries of the surface modes, and also demonstrate the existence and tunability of nonlinear Tamm states in binary photonic crystals with nonlinear response.Comment: 11 pages, 3 figures, submitted to Optics Communication

Death and transfiguration in static staphylococcus epidermidis cultures

The overwhelming majority of bacteria live in slime embedded microbial communities termed biofilms, which are typically adherent to a surface. However, when several Staphylococcus epidermidis strains were cultivated in static liquid cultures, macroscopic aggregates were seen floating within the broth and also sedimented at the test tube bottom. Light- and electron microscopy revealed that early-stage aggregates consisted of bacteria and extracellular matrix, organized in sheetlike structures. Perpendicular under the sheets hung a network of periodically arranged, bacteria-associated strands. During the extended cultivation, the strands of a subpopulation of aggregates developed into cross-connected wall-like structures, in which aligned bacteria formed the walls. The resulting architecture had a compartmentalized appearance. In late-stage cultures, the wall-associated bacteria disintegrated so that, henceforth, the walls were made of the coalescing remnants of lysed bacteria, while the compartment-like organization remained intact. At the same time, the majority of strand containing aggregates with associated culturable bacteria continued to exist. These observations indicate that some strains of Staphylococcus epidermidis are able to build highly sophisticated structures, in which a subpopulation undergoes cell lysis, presumably to provide continued access to nutrients in a nutrient-limited environment, whilst maintaining structural integrity