Diffusion in spatially and temporarily inhomogeneous media: Effects of turbulent mixing

We consider diffusion of a passive substance C in a phase-separating nonmiscible binary alloy under turbulent mixing. The substance is assumed to have different diffusion coefficients in the pure phases A and B, leading to a spatially and temporarily dependent diffusion ¿coefficient¿ in the diffusion equation plus convective term. In this paper we consider especially the effects of a turbulent flow field coupled to both the Cahn-Hilliard type evolution equation of the medium and the diffusion equation (both, therefore, supplemented by a convective term). It is shown that the formerly observed prolonged anomalous diffusion [H. Lehr, F. Sagués, and J.M. Sancho, Phys. Rev. E 54, 5028 (1996)] is no longer seen if a flow of sufficient intensity is supplied

DEXTER: Automatic Extraction of Domain-Specific Glossaries for Language Teaching

[EN] Many researchers emphasize the importance of corpora in the design of Language-for-Specific-Purposes courses in higher education. However, identifying those lexical units which belong to a given specific domain is often a complex task for language teachers, where simple introspection or concordance analysis does not really become effective. The goal of this paper is to describe DEXTER, an open-access platform for data mining and terminology management, whose aim is not only the search, retrieval, exploration and analysis of texts in domain-specific corpora but also the automatic extraction of specialized words from the domain.Financial support for this research has been provided by the DGI, Spanish Ministry of Education and Science, grant FFI2011-29798-C02-01.Periñán Pascual, JC.; Mestre-Mestre, EM. (2015). DEXTER: Automatic Extraction of Domain-Specific Glossaries for Language Teaching. Procedia Social and Behavioral Sciences. 198:377-385. https://doi.org/10.1016/j.sbspro.2015.07.45737738519

Suppression of scroll wave turbulence by noise

Rotating scroll waves are dynamical spatiotemporal structures characteristic of three-dimensional active media. It is well known that, under low excitability conditions, scroll waves develop an intrinsically unstable dynamical regime that leads to a highly disorganized pattern of wave propagation. Such a ¿turbulent¿ state bears some resemblance to fibrillation states in cardiac tissue. We show here that this unstable regime can be controlled by using a spatially distributed random forcing superimposed on a control parameter of the system. Our results are obtained from numerical simulations but an explicit analytical argument that rationalizes our observations is also presented

Cognitive Fusion Mediates the Relationship between Dispositional Mindfulness and Negative Affects: A Study in a Sample of Spanish Children and Adolescent School Students

Nowadays, mindfulness-based interventions (MBI) have experienced a remarkable development of studies among childhood and adolescent interventions. For this reason, dispositional mindfulness (DM) measures for children and adolescents have been developed to determine the e ectiveness of MBI at this age stage. However, little is known about how key elements of DM (for example, cognitive de/fusion or experiential avoidance that both confirm psychological inflexibility) are involved in the mechanisms of the children and adolescents’ mental health outcomes. This research examined the mediating e ect of cognitive fusion between DM and anxiety and other negative emotional states in a sample of 318 Spanish primary-school students (aged between 8 and 16 years, M = 11.24, SD = 2.19, 50.8% males). Participants completed the AFQ-Y (Avoidance and Fusion Questionnaire for youth), which is a measure of psychological inflexibility that encompasses cognitive defusion and experiential avoidance; CAMM (DM for children and adolescents), PANAS-N (positive and negative a ect measure for children, Spanish version of PANASC), and STAIC (an anxiety measure for children). The study accomplished ethical standards. As MBI relevant literature has suggested, cognitive defusion was a significant mediator betweenDMand symptoms of both negative emotions and anxiety in children and adolescents. However, experiential avoidance did not show any significant mediating relationship. Probably, an improvement of the assessment of experiential avoidance is needed. MBI programs for children and adolescents may include more activities for reducing e ects of the cognitive defusion on their emotional distress

Coherence and anticoherence resonance tunned by noise

We present numerical evidence and a theoretical analysis of the appearance of anticoherence resonance induced by noise, not predicted in former analysis of coherence resonance. We have found that this phenomenon occurs for very small values of the intensity of the noise acting on an excitable system, and we claim that this is a universal signature of a nonmonotonous relaxational behavior near its oscillatory regime. Moreover, we demonstrate that this new phenomenon is totally compatible with the standard situation of coherence resonance appearing at intermediate values of noise intensity

Evaporation and coarsening dynamics with open boundaries

We present a study of the evaporation dynamics of a substance undergoing a coarsening process. The system is modeled by the Cahn-Hilliard equation with absorbing boundaries. We have found that the dynamics, although of a diffusive nature, is much slower than the usual one without coarsening. Analytical and simulation results are in reasonable agreement

Competitive evaporation in arrays of droplets

We consider the evaporation of periodic arrays of initially equal droplets in two-dimensional systems with open (absorbing) boundaries. Our study is based on the numerical solution of the Cahn-Hilliard equation. We show that due to cooperative effects the droplets which are further from the boundary may evaporate earlier than those in the boundary¿s vicinity. The time evolution of the overall amount of matter in the system is also studied

New forms of social interaction: virtual communication and health

It is examined if the relationship empirically demonstrated between health and face-to-face social interactions is confirmed when it is virtual. The objective is to know if the perception of psychological well-being and receiving social support would explain the frequency of participation in virtual social networks (VSN). An ex-post-facto design was applied to a sample of 510 university Internet users (age, M = 22.89, SD = 5.67, 78.9% women). The level of psychological well-being (Spanish adaptation of the Ryff Psychological Well-Being Scale), social support (Family Social Support and Friends questionnaire - AFA) and the frequency of use of VSN are evaluated. To determine the relationships between the variables, correlation and hierarchical regression analyzes were carried out. The relative contribution of the perception of psychological well-being and of obtaining social support in the frequency of VSN use is confirmed, controlling the influences of age and gender. Specifically, the perception of having less ability to dominate the social environment and to obtain social support for friendships through VSN explains and allows predicting the increase in the frequency of use of such networks.Se examina si la relación demostrada empíricamente entre salud e interacciones sociales presenciales se confirma cuando ésta es virtual. El objetivo es conocer si la percepción de bienestar psicológico y de recibir apoyo social explicaría la frecuencia de participación en redes sociales virtuales (RSV). Se aplica un diseño ex-post-facto sobre una muestra de 510 internautas universitarios (edad; M =22,89; DT= 5,67; 78,9% mujeres). Se evalúa el nivel de bienestar psicológico (adaptación española de la Escala de Bienestar Psicológico de Ryff), de apoyo social (cuestionario Apoyo Social Familiar y Amigos - AFA) y la frecuencia de uso de las RSV. Para determinar las relaciones entre las variables se realizaron análisis de correlación y de regresión jerárquica Se confirma la contribución relativa de la percepción de bienestar psicológico y de obtención de apoyo social en la frecuencia de uso de RSV, controlando las influencias de la edad y el género. Concretamente, la percepción de poseer menor capacidad de dominar el ambiente social y la de obtener apoyo social por las amistades a través de las RSV, explica y permite predecir el incremento en la frecuencia de uso de dichas redes

Anandamide inhibits Theiler's virus induced VCAM-1 in brain endothelial cells and reduces leukocyte transmigration in a model of blood brain barrier by activation of CB1 receptors

<p>Abstract</p> <p>Background</p> <p>VCAM-1 represents one of the most important adhesion molecule involved in the transmigration of blood leukocytes across the blood-brain barrier (BBB) that is an essential step in the pathogenesis of MS. Several evidences have suggested the potential therapeutic value of cannabinoids (CBs) in the treatment of MS and their experimental models. However, the effects of endocannabinoids on VCAM-1 regulation are poorly understood. In the present study we investigated the effects of anandamide (AEA) in the regulation of VCAM-1 expression induced by Theiler's virus (TMEV) infection of brain endothelial cells using <it>in vitro </it>and <it>in vivo </it>approaches.</p> <p>Methods</p> <p>i) <it>in vitro</it>: VCAM-1 was measured by ELISA in supernatants of brain endothelial cells infected with TMEV and subjected to AEA and/or cannabinoid receptors antagonist treatment. To evaluate the functional effect of VCAM-1 modulation we developed a blood brain barrier model based on a system of astrocytes and brain endothelial cells co-culture. ii) <it>in vivo</it>: CB₁receptor deficient mice (Cnr1^-/-) infected with TMEV were treated with the AEA uptake inhibitor UCM-707 for three days. VCAM-1 expression and microglial reactivity were evaluated by immunohistochemistry.</p> <p>Results</p> <p>Anandamide-induced inhibition of VCAM-1 expression in brain endothelial cell cultures was mediated by activation of CB₁receptors. The study of leukocyte transmigration confirmed the functional relevance of VCAM-1 inhibition by AEA. <it>In vivo </it>approaches also showed that the inhibition of AEA uptake reduced the expression of brain VCAM-1 in response to TMEV infection. Although a decreased expression of VCAM-1 by UCM-707 was observed in both, wild type and CB₁receptor deficient mice (Cnr1^-/-), the magnitude of VCAM-1 inhibition was significantly higher in the wild type mice. Interestingly, Cnr1^-/-mice showed enhanced microglial reactivity and VCAM-1 expression following TMEV infection, indicating that the lack of CB₁receptor exacerbated neuroinflammation.</p> <p>Conclusions</p> <p>Our results suggest that CB₁receptor dependent VCAM-1 inhibition is a novel mechanism for AEA-reduced leukocyte transmigration and contribute to a better understanding of the mechanisms underlying the beneficial role of endocannabinoid system in the Theiler's virus model of MS.</p