Rudiments of Holography

An elementary introduction to Maldacena's AdS/CFT correspondence is given, with some emphasis in the Fefferman-Graham construction. This is based on lectures given by one of us (E.A.) at the Universidad Autonoma de Madrid.Comment: 60 pages, additional misprints corrected, references adde

Lexical and phonological processing in visual word recognition by stuttering children: Evidence from Spanish

A number of studies have pointed out that stuttering-like disfluencies could be the result of failures in central and linguistic processing. The goal of the present paper is to analyze if stuttering implies deficits in the lexical and phonological processing in visual word recognition. This study compares the performance of 28 children with and without stuttering in a standard lexical decision task in a transparent orthography: Spanish. Word frequency and syllable frequency were manipulated in the experimental words. Stutterers were found to be considerably slower (in their correct responses) and produced more errors than the non- stutterers (?(1) = 36.63, p and lt;.001, ?2 =.60). There was also a facilitation effect of syllable frequency, restricted to low frequency words and only in the stutterers group (t1(10) = 3.67, p and lt;.005; t2(36) = 3.10, p and lt;.001). These outcomes appear to suggest that the decoding process of stutterers exhibits a deficit in the interface between the phonological-syllabic level and the word level. Copyright © Universidad Complutense de Madrid and Colegio Oficial de Psicólogos de Madrid 2014

Structural properties of various sodium thiogermanate glasses through DFT-based molecular dynamics simulations

We present a study of the structural properties of (x)Na$_2$S-(1-x)GeS$_2$ glasses through DFT-based molecular dynamics simulations, at different sodium concentrations ($0<x<0.5$). We computed the radial pair correlation functions as well as the total and partial structure factors. We also analyzed the evolution of the corner- and edge-sharing intertetrahedral links with the sodium concentration and show that the sodium ions exclusively destroy the former. With the increase of the sodium concentration the ``standard'' FSDP disappears and a new pre-peak appears in the structure factor which can be traced back in the Na-Na partial structure factor. This self organization of the sodium ions is coherent with Na-rich zones that we find at high modifier concentration.Comment: 9 pages, 7 figures; to be published in Phys. Rev.

Strain balanced quantum posts

Quantum posts are assembled by epitaxial growth of closely spaced quantum dot layers, modulating the composition of a semiconductor alloy, typically InGaAs. In contrast with most self-assembled nanostructures, the height of quantum posts can be controlled with nanometer precision, up to a maximum value limited by the accumulated stress due to the lattice mismatch. Here we present a strain compensation technique based on the controlled incorporation of phosphorous, which substantially increases the maximum attainable quantum post height. The luminescence from the resulting nanostructures presents giant linear polarization anisotropy.Comment: Submitted to Applied Physics Letters (7th March 2011). 4 pages, 4 figure

The Dirichlet Obstruction in AdS/CFT

The obstruction for a perturbative reconstruction of the five-dimensional bulk metric starting from the four-dimensional metric at the boundary,that is, the Dirichlet problem, is computed in dimensions $6\leq d\leq 10$ and some comments are made on its general structure and, in particular, on its relationship with the conformal anomaly, which we compute in dimension $d=8$.Comment: 13 pages, references added (this paper supersedes hep-th/0206140, "A Note on the Bach Tensor in AdS/CFT", which has been withdrawn

The Free Institute of Education and Pierre de Coubertin: physical education to educate within liberty

Esta investigación analiza las relaciones entre dos reformas educativas: la de Pierre de Coubertin (1863-1937), con la que pretendía “Rebroncer la France”, y la que impulsó la Institución Libre de Enseñanza (ILE), para la renovación de España. Con ese propósito, se realiza un análisis documental de diferentes fuentes primarias. Entre ellas destacan la relación epistolar entre Coubertin, Giner de los Ríos y Bartolomé Cossío (entre 1888 y 1899), y entre Giner de los Ríos y Aniceto Sela, representante español en el Congreso de la Sorbona de 1894, así como el Boletín de la ILE, órgano difusor de su ideario, y los propios escritos de Coubertin. Este trabajo, resultado parcial de nuestra investigación, presenta alguno de los numerosos puntos de confluencia entre ambas iniciativas de reforma social, promotoras de una renovación significativa de la educación de los ciudadanos, con una destacada atención a los ejercicios físicos, los juegos y los deportes.This research paper examines the relationship between two educational reforms: Pierre de Coubertin’s (1863-1973), with its ambitious “Rebroncer la France”, and the reform for the renovation of Spain launched by the Free Institute of Education (ILE). With this aim, different primary sources are studied. Among others, the following ones stand out: the correspondence between Coubertin, Giner de los Ríos and Bartolomé Cossío, from 1888 to 1899, and the correspondence between Giner de los Ríos and Aniceto Sela, who was the Spanish spokesman at the 1894 Paris Sorbonne Congress; but also the Bulletin of the ILE, the organ that disseminated its ideals, and Coubertin's own writings. This research paper includes part of our findings and points out some of the coincidences between both initiatives of social reform. They both promoted a significant renovation of the education of citizens, with special attention to physical exercise, games and sport

Cryptanalysis of a novel cryptosystem based on chaotic oscillators and feedback inversion

An analysis of a recently proposed cryptosystem based on chaotic oscillators and feedback inversion is presented. It is shown how the cryptosystem can be broken when Duffing's oscillator is considered. Some implementation problems of the system are also discussed.Comment: 9 pages, 3 figures, latex forma

Emotion, Psychological Well-Being and Their Influence on Resilience. A Study with Semi-Professional Athletes

The objective of the present study is to analyze the influence of coaches on emotional intelligence and on levels of anxiety, motivation, self-esteem, and resilience among athletes. Five-hundred forty-seven semi-professional athletes between the ages of 16 and 19 participated in this study. Various statistical analyses were conducted which explain the causal relationships between the variables. The results, obtained using a structural equations model, find that while autonomy support positively predicts emotional intelligence, perceived control predicts it negatively. Moreover, emotional intelligence positively predicts self-esteem and self-determined motivation, but negatively predicts anxiety. Other results show that self-esteem positively predicts self-determined motivation, whereas anxiety predicts it negatively. Finally, self-determined motivation positively predicts resilience. Indeed, the study demonstrates the influence and the importance of coaches in relation to the emotional intelligence, psychological well-being, and motivational processes of adolescent athletes when the latter engage in their respective sports. These results help to better understand how different behavioral, emotional, and social aspects belonging to the athlete interrelate with one another during competition

A cloud-based parallel system for locating customers in indoor malls

Advances in techniques of locating mobile users have promoted the development of marketing campaigns based on customers’ location. WiFi-based location methods have proven their usefulness in tracking and locating customers within a indoor mall. Nevertheless, in some cases the performance of these methods prevents them from being used in real scenarios. In this paper, we have faced the problem of improving the execution time and reducing the cost of one of these WiFi-based location methods. Parallel programming techniques, service-oriented technologies and the cloud computing paradigm have been combined to solve efficiently these problems. The resulting system has been deployed in the Amazon EC2 environment, evaluating different configuration and deployment options

Cultural Preservation of Ethnomedicine in Peru

In conjunction with the Minority Health & Health Disparities International Research Training program at San Diego State University, three Linfield students contributed to the ongoing Peru Ethnomedical Project in Trujillo, Peru by: Conducting surveys in two neighborhoods on the edge of the city; Creating a medicinal plant garden in the Chan Chan archaeological site museum. Surveys conducted in Moche, Trujillo were part of a larger study supervised by anthropologists Douglas Sharon and Thomas Love. The research aims to evaluate the usage of medicinal plants in rural and urban Peruvian communities. Linfield’s contribution focused on the creation of the medicinal garden to serve as a community model and educational program. The overall purpose of the 2015 summer faculty collaborative project was to: Preserve the knowledge of these practices; Analyze the plant properties; Publish the information; Provide the community with a garden that reflects the commonly used plants; Educate new generations; Bring back and apply this knowledge in the Linfield community