Diffusion dynamics on multiplex networks

We study the time scales associated to diffusion processes that take place on multiplex networks, i.e. on a set of networks linked through interconnected layers. To this end, we propose the construction of a supra-Laplacian matrix, which consists of a dimensional lifting of the Laplacian matrix of each layer of the multiplex network. We use perturbative analysis to reveal analytically the structure of eigenvectors and eigenvalues of the complete network in terms of the spectral properties of the individual layers. The spectrum of the supra-Laplacian allows us to understand the physics of diffusion-like processes on top of multiplex networks.Comment: 6 Pages including supplemental material. To appear in Physical Review Letter

Analogy construction and success in mathematics and science problem-solving: a study with secondary students

We conducted an empirical study to analyse the association between students" perception of surface and structural analogies among problems, and their algebraic success. Algebraic success was measured by the equations selected to solve each problem. Different surface and structural relationships between one source problem and four target problems were considered. We also considered high (daily life) and low (scientific) familiarity contexts for the problems. Similarities and differences between the source and each target problem were explicitly asked to students. Results showed a significant correlation between detecting the correct structural relation between these problems and selecting the correct equations to solve the target ones. Low familiarity (science) problems obtained lower success independently of other factors. Usual teaching procedures, based on isomorphism, could increase the probability that students consider isomorphism the only possible relationship between problems

Efecto pantalla y efecto Sísifo: dos fenómenos didácticos en la resolución de problemas por transferencia analógica

Se presenta un estudio cualitativo, basado en entrevistas semi-estructuradas, de 2 casos que muestran dos fenómenos didácticos de interés en la resolución de problemas por transferencia analógica. El primero muestra un ‘efecto pantalla’, en el cual el sujeto no puede acceder a la estructura de los problemas a partir de los enunciados. En el segundo caso, el sujeto no logra alcanzar un estado estable de comprensión, a pesar de su avance, y por tanto acaba por retroceder a un estado de ausencia de conflicto cognitivo, pero indeseado desde el punto de vista didáctico (‘efecto Sísifo’). Se discuten las posibles implicaciones didácticas de estos casos

La investigación sobre la influencia de las estrategias y la motivación en la resolución de problemas: implicaciones para la enseñanza

En este trabajo se analiza el papel de las estrategias y de la motivación de los estudiantes en la resolución de problemas mediante una revisión bibliográfica que cubre diferentes áreas de conocimiento. Se distinguen dos tipos de estrategias en resolución de problemas, las cognitivas y las metacognitivas, y se incide especialmente, por su relevancia, en las metacognitivas. Se destaca, asimismo, la influencia de la motivación en el éxito en la resolución de problemas. A partir de toda la información recopilada, se extraen las oportunas consecuencias didácticas. In this paper it is analysed the role of students" strategies and motivation in problem solving by means of a review of research that includes relevant publications about these subjects. It is distinguished two types of strategies in problem solving: cognitive and metacognitive. Metacognitive strategies are especially stood out because of their significance. Motivation is also pointed out as very influential in problem solving success. Starting from compiled information we extract the convenient didactic implications

Una revisión de los procesos de transferencia para el aprendizaje y enseñanza de las ciencias

En este trabajo se introduce el concepto de transferencia en el aprendizaje, se clasifican en sus diferentes tipos y se discute su importancia en la resolución de problemas de ciencias y matemáticas. Además se discute el papel de los procesos de transferencia y cómo se pueden mejorar en la enseñanza de las ciencias. A partir de todo ello, se recomiendan algunas medidas instruccionales que pueden ser aplicadas en el aula de ciencias

Effects of Topic Familiarity on Analogical Transfer in Problem- Solving: A Think-Aloud Study of Two Singular Cases

We conducted a qualitative research of case studies based on think-aloud protocols. The aim was to carry out in-depth analyse secondary students¿ cognitive difficulties appearing in early stages of transfer processes in problem-solving. The task was to relate several source problems to a target problem, in order to solve it effectively. Source and target problems had different Surface and/or Structural similarities. In this paper, the solvers¿ high or low Familiarity with the problem stories on transfer processes was also focused on. Two emergent instructional phenomena are described, both associated to specific students¿ cognitive obstacles to achieve success in solving the target problem: the `Screen effect¿ and the `Sisyphus effect¿. The obstacles were harder for low Familiarity problems

Estudios sobre Comprensión y Control de la comprensión en Resolución de Problemas académicos

This paper aims at summarizing in a cohesive way some research developed and focused on understanding word problems. Four empirical studies are described: The first study was devoted to the analysis of the initial steps in the transfer process, codifying and mapping . The second study added the relationship between the adequate construction of analogies and success in problem solving. The following study tried to go deep in cognitive difficulties appearing in solving-by-analogy processes. Finally, we explored students' monitoring when they try to understand solved problems provided by teachers

Hierarchical habitat-use by an endangered steppe bird in fragmented landscapes is associated with large connected patches and high food availability

Multidimensional approaches must be employed when addressing habitat use patterns. In this study, we aim to elucidate the hierarchical nature of space use by species inhabiting fragmented landscapes, using the threatened Dupont’s lark (Chersophilus duponti). The intensity of space use by Dupont’s lark was estimated using the Kernel Density Function on territory locations in 2015. We measured descriptors of habitat quality at metapopulation (connectivity and patch size), landscape (land-use types and anthropogenic disturbance) and microhabitat-scale (plant structure and composition, herbivore abundance and food availability) at 37 sampling stations. We fitted a Partial Least Squares Regression (PLSR) which yielded two components, accounting for 81% of total variance. Metapopulation-scale factors had the greatest explanatory power (32%), followed by microhabitat (17%) landscape (10%) and spatial predictors (3.6%). Connectivity and patch size were key factors explaining habitat use, and wind farms had a negative effect. At microhabitat-scale, space use was positively associated with Coleoptera, Orthoptera, Araneae and Diptera biomass, but negatively with Formicidae and Blattodea biomass, the cover of Stipa spp, Koeleria vallesiana and moss. This research highlights the hierarchical nature of habitat use in fragmented landscapes. Therefore, conservation measures should ensure connectivity, guarantee a minimum patch size, and improve habitat quality within patchesWe wish to thank Luis M. Carrascal for the help with statistical analysis. In addition, we are grateful to Álvaro Ortega, Jonathan Pereira and Carlos Talabante for their help with arthropods identification, and to Iris Calleja, Rodrigo A. Martínez, Laura Aylagas and Jaqueline Boldt for their help during fieldwork. We are grateful to two anonymous reviewers for their constructive comments that helped to improve the manuscript. This study was supported by Fundación Patrimonio Natural de Castilla y León, the European Commission (Life-Ricotí project LIFE15-NAT-ES-000802) and the BBVA Foundation (BBVA-Dron Ricotí project). This paper contributes to project REMEDINAL-3 from CAM

Ion transport and selectivity in nanopores with spatially inhomogeneous fixed charge distributions

Polymeric nanopores with fixed charges show ionic selectivity when immersed in aqueous electrolyte solutions. The understanding of the electrical interaction between these charges and the mobile ions confined in the inside nanopore solution is the key issue in the design of potential applications. The authors have theoretically described the effects that spatially inhomogeneous fixed charge distributions exert on the ionic transport and selectivity properties of the nanopore. A comprehensive set of one-dimensional distributions including the skin, core, cluster, and asymmetric cases are analyzed on the basis of the Nernst-Planck equations. Current-voltage curves, nanopore potentials, and transport numbers are calculated for the above distributions and compared with those obtained for a homogeneously charged nanopore with the same average fixed charge concentration. The authors have discussed if an appropriate design of the spatial fixed charge inhomogeneity can lead to an enhancement of the transport and selectivity with respect to the homogeneous nanopore case. Finally, they have compared the theoretical predictions with relevant experimental [email protected] [email protected]

Testing a model for the monitoring of worked-out algebra-problem examples: from behaviours to outcomes on a math task

This study aimed at testing an extension of a theoretical model for the metacognitive monitoring mechanism implied in the detection of inconsistencies when the information provided includes abstract symbols in addition to plain text. Ninety-four postgraduates of STEM specialities were asked to read a worked-out algebra-problem example and to report any incoherence, inconsistency, or error detected in the statement or in the solving procedure. A set of model inspired indexes was defined to describe participants¿ behaviour along the task. The Read & Answer software was used to record online individual processing data and participants¿ reports. Results supported model predictions. Indexes correctly predicted participants¿ outcomes in the task with high accuracy. Specific students¿ behaviours could be associated to observed task outcomes with sufficient reliability within the limitations of the study. In addition, algebra processing was compared with plain text processing