Information search and similarity based on Web 2.0 and semantic technologies

The World Wide Web provides a huge amount of information described in natural language at the current society’s disposal. Web search engines were born from the necessity of finding a particular piece of that information. Their ease of use and their utility have turned these engines into one of the most used web tools at a daily basis. To make a query, users just have to introduce a set of words - keywords - in natural language and the engine answers with a list of ordered resources which contain those words. The order is given by ranking algorithms. These algorithms use basically two types of features: dynamic and static factors. The dynamic factor has into account the query; that is, those documents which contain the keywords used to describe the query are more relevant for that query. The hyperlinks structure among documents is an example of a static factor of most current algorithms. For example, if most documents link to a particular document, this document may have more relevance than others because it is more popular. Even though currently there is a wide consensus on the good results that the majority of web search engines provides, these tools still suffer from some limitations, basically 1) the loneliness of the searching activity itself; and 2) the simple recovery process, based mainly on offering the documents that contains the exact terms used to describe the query. Considering the first problem, there is no doubt in the lonely and time-consuming process of searching relevant information in the World Wide Web. There are thousands of users out there that repeat previously executed queries, spending time in taking decisions of which documents are relevant or not; decisions that may have been taken previously and that may be do the job for similar or identical queries for other users. Considering the second problem, the textual nature of the current Web makes the reasoning capability of web search engines quite restricted; queries and web resources are described in natural language that, in some cases, can lead to ambiguity or other semantic-related difficulties. Computers do not know text; however, if semantics is incorporated to the text, meaning and sense is incorporated too. This way, queries and web resources will not be mere sets of terms, but lists of well-defined concepts. This thesis proposes a semantic layer, known as Itaca, which joins simplicity and effectiveness in order to endow with semantics both the resources stored in the World Wide Web and the queries used by users to find those resources. This is achieved through collaborative annotations and relevance feedback made by the users themselves, which describe both the queries and the web resources by means of Wikipedia concepts. Itaca extends the functional capabilities of current web search engines, providing a new ranking algorithm without dispensing traditional ranking models. Experiments show that this new architecture offers more precision in the final results obtained, keeping the simplicity and usability of the web search engines existing so far. Its particular design as a layer makes feasible its inclusion to current engines in a simple way.Internet pone a disposición de la sociedad una enorme cantidad de información descrita en lenguaje natural. Los buscadores web nacieron de la necesidad de encontrar un fragmento de información entre tanto volumen de datos. Su facilidad de manejo y su utilidad los han convertido en herramientas de uso diario entre la población. Para realizar una consulta, el usuario sólo tiene que introducir varias palabras clave en lenguaje natural y el buscador responde con una lista de recursos que contienen dichas palabras, ordenados en base a algoritmos de ranking. Estos algoritmos usan dos tipos de factores básicos: factores dinámicos y estáticos. El factor dinámico tiene en cuenta la consulta en sí; es decir, aquellos documentos donde estén las palabras utilizadas para describir la consulta serán más relevantes para dicha consulta. La estructura de hiperenlaces en los documentos electrónicos es un ejemplo de factor estático. Por ejemplo, si muchos documentos enlazan a otro documento, éste último documento podrá ser más relevante que otros. Si bien es cierto que actualmente hay consenso entre los buenos resultados de estos buscadores, todavía adolecen de ciertos problemas, destacando 1) la soledad en la que un usuario realiza una consulta; y 2) el modelo simple de recuperación, basado en ver si un documento contiene o no las palabras exactas usadas para describir la consulta. Con respecto al primer problema, no hay duda de que navegar en busca de cierta información relevante es una práctica solitaria y que consume mucho tiempo. Hay miles de usuarios ahí fuera que repiten sin saberlo una misma consulta, y las decisiones que toman muchos de ellos, descartando la información irrelevante y quedándose con la que realmente es útil, podrían servir de guía para otros muchos. Con respecto al segundo, el carácter textual de la Web actual hace que la capacidad de razonamiento en los buscadores se vea limitada, pues las consultas y los recursos están descritos en lenguaje natural que en ocasiones da origen a la ambigüedad. Los equipos informáticos no comprenden el texto que se incluye. Si se incorpora semántica al lenguaje, se incorpora significado, de forma que las consultas y los recursos electrónicos no son meros conjuntos de términos, sino una lista de conceptos claramente diferenciados. La presente tesis desarrolla una capa semántica, Itaca, que dota de significado tanto a los recursos almacenados en la Web como a las consultas que pueden formular los usuarios para encontrar dichos recursos. Todo ello se consigue a través de anotaciones colaborativas y de relevancia realizadas por los propios usuarios, que describen tanto consultas como recursos electrónicos mediante conceptos extraídos de Wikipedia. Itaca extiende las características funcionales de los buscadores web actuales, aportando un nuevo modelo de ranking sin tener que prescindir de los modelos actualmente en uso. Los experimentos demuestran que aporta una mayor precisión en los resultados finales, manteniendo la simplicidad y usabilidad de los buscadores que se conocen hasta ahora. Su particular diseño, a modo de capa, hace que su incorporación a buscadores ya existentes sea posible y sencilla.Programa Oficial de Posgrado en Ingeniería TelemáticaPresidente: Asunción Gómez Pérez.- Secretario: Mario Muñoz Organero.- Vocal: Anselmo Peñas Padill

Programación en C con aprendizaje activo, evaluación continua y trabajo en equipo: caso de estudio

La adaptación al Espacio Europeo de Educación Superior ha supuesto el rediseño de parte de los planes de estudios por parte de las universidades. En este artículo se describe el proceso de concepción, diseño y despliegue de una asignatura de programación en C que incluye como principales novedades la adopción de una metodología de aprendizaje activo, un esquema de evaluación continua y la inclusión de trabajo en equipo. La asignatura se ha impartido en el curso 2009/2010 a cerca de 200 alumnos. Durante este período se ha obtenido abundante realimentación por parte de los alumnos sobre aquellos aspectos del curso más relevantes (positivos y negativos). Esta información ha permitido comprender más en detalle el proceso de asimilación y la efectividad de los cambios introducidos.Peer Reviewe

Ztreamy: a middleware for publishing semantic streams on the web

In order to make the semantic sensor Web a reality, middleware for efficiently publishing semantically-annotated data streams on the Web is needed. Such middleware should be designed to allow third parties to reuse and mash-up data coming from streams. These third parties should even be able to publish their own value-added streams derived from other streams and static data. In this work we present Ztreamy, a scalable middleware platform for the distribution of semantic data streams through HTTP. The platform provides an API for both publishing and consuming streams, as well as built-in filtering services based on data semantics. A key contribution of our proposal with respect to other related systems in the state of the art is its scalability. Our experiments with Ztreamy show that a single server is able, in some configurations, to publish a real-time stream to up to 40.000 simultaneous clients with delivery delays of just a few seconds, largely outperforming other systems in the state of the art.Publicad

SEBIO: A Semantic BioInformatics Platform for the New E-Science

Knowledge integration and exchange of data within and among organizations is a universally recognized need in bioinformatics and genomics research through the e-science field. The main problem looming over the lack of integration is the fact that the current Web is an environment primarily developed for human users and micro-array data resources lack widely accepted standards; this leads to a tremendous data heterogeneity. Using semantic technologies as a key technology for interoperation of various datasets enables knowledge integration of the vast amount of biological and biomedical data. In this paper, we aim at providing a semantically-enhanced bioinformatics platform (SEBIO), which handles these issues effectively. We will describe the problems arisen and the solutions applied so far. For that, the SEBIO approach is unfolded and its main components explained, to see in more detail how perfectly it copes with the aforementioned difficulties

Course Quality Improvement using Mid-semester Feedback

Quality control mechanisms are becoming more important in higher educational institutions. Student evaluation of teaching is typically used to obtain feedback from students about a learning experience but its effect in the course may take too long. Fast feedback mechanisms, in exchange, look at obtaining feedback in a way that corrective measures can be applied quickly. In this paper, a process is described to obtain feedback from the students about a course, analyse the received results, and identify the most significant aspects. The process has been applied to a course and led to some adjustments that had immediate impact on the course.Work partially funded by the Learn3 project, "Plan Nacional de I+D+I TIN2008-05163/TSI", the Best Practice Network ICOPER (Grant No. ECP-2007-EDU-417007), the Flexo Project "Plan Nacional de Investigación Científica, Desarrollo e Innovación Tecnolóogica" (Ref. TSI-020301-2008-19), and the "Emadrid: Investigación y desarrollo de tecnologías para el e-learning en la Comunidad de Madrid" project (S2009/TIC-1650).Publicad

Ankyrin-B is a PI3P effector that promotes polarized α5β1-integrin recycling via recruiting RabGAP1L to early endosomes

Endosomal membrane trafficking requires coordination between phosphoinositide lipids, Rab GTPases, and microtubule-based motors to dynamically determine endosome identity and promote long-range organelle transport. Here we report that ankyrin-B (AnkB), through integrating all three systems, functions as a critical node in the protein circuitry underlying polarized recycling of α5β1-integrin in mouse embryonic fibroblasts, which enables persistent fibroblast migration along fibronectin gradients. AnkB associates with phosphatidylinositol 3-phosphate (PI3P)-positive organelles in fibroblasts and binds dynactin to promote their long-range motility. We demonstrate that AnkB binds to Rab GTPase Activating Protein 1-Like (RabGAP1L) and recruits it to PI3P-positive organelles, where RabGAP1L inactivates Rab22A, and promotes polarized trafficking to the leading edge of migrating fibroblasts. We further determine that α5β1-integrin depends on an AnkB/RabGAP1L complex for polarized recycling. Our results reveal AnkB as an unexpected key element in coordinating polarized transport of α5β1-integrin and likely of other specialized endocytic cargos

Programación en C con aprendizaje activo, evaluación continua y trabajo en equipo: caso de estudio

La adaptación al Espacio Europeo de Educación Superior ha supuesto el rediseño de parte de los planes de estudios por parte de las universidades. En este artículo se describe el proceso de concepción, diseño y despliegue de una asignatura de programación en C que incluye como principales novedades la adopción de una metodología de aprendizaje activo, un esquema de evaluación continua y la inclusión de trabajo en equipo. La asignatura se ha impartido en el curso 2009/2010 a cerca de 200 alumnos. Durante este período se ha obtenido abundante realimentación por parte de los alumnos sobre aquellos aspectos del curso más relevantes (positivos y negativos). Esta información ha permitido comprender más en detalle el proceso de asimilación y la efectividad de los cambios introducidos.Este trabajo ha sido financiado en parte por el proyecto Emadrid: Investigación y desarrollo de tecnologías para el e-learning en la Comunidad de Madrid (Ref. S2009/TIC-1650), el proyecto Learn3 del Plan Nacional de I+D+I (Ref. TIN2008-05163/TSI) y el proyecto Flexo del Plan Nacional de Investigación Científica, Desarrollo e Innovación Tecnológica (Ref. TSI-020301-2008-19

Developmental mechanism of the periodic membrane skeleton in axons

Actin, spectrin, and associated molecules form a periodic sub-membrane lattice structure in axons. How this membrane skeleton is developed and why it preferentially forms in axons are unknown. Here, we studied the developmental mechanism of this lattice structure. We found that this structure emerged early during axon development and propagated from proximal regions to distal ends of axons. Components of the axon initial segment were recruited to the lattice late during development. Formation of the lattice was regulated by the local concentration of βII spectrin, which is higher in axons than in dendrites. Increasing the dendritic concentration of βII spectrin by overexpression or by knocking out ankyrin B induced the formation of the periodic structure in dendrites, demonstrating that the spectrin concentration is a key determinant in the preferential development of this structure in axons and that ankyrin B is critical for the polarized distribution of βII spectrin in neurites. DOI: http://dx.doi.org/10.7554/eLife.04581.00

Ankyrin-B is a PI3P effector that promotes polarized a5b1-integrin recycling via recruiting RabGAP1L to early endosomes

Abstract Endosomal membrane trafficking requires coordination between phosphoinositide lipids, Rab GTPases, and microtubule-based motors to dynamically determine endosome identity and promote long-range organelle transport. Here we report that ankyrin-B (AnkB), through integrating all three systems, functions as a critical node in the protein circuitry underlying polarized recycling of a5b1-integrin in mouse embryonic fibroblasts, which enables persistent fibroblast migration along fibronectin gradients. AnkB associates with phosphatidylinositol 3-phosphate (PI3P)-positive organelles in fibroblasts and binds dynactin to promote their long-range motility. We demonstrate that AnkB binds to Rab GTPase Activating Protein 1-Like (RabGAP1L) and recruits it to PI3P-positive organelles, where RabGAP1L inactivates Rab22A, and promotes polarized trafficking to the leading edge of migrating fibroblasts. We further determine that a5b1-integrin depends on an AnkB/RabGAP1L complex for polarized recycling. Our results reveal AnkB as an unexpected key element in coordinating polarized transport of a5b1-integrin and likely of other specialized endocytic cargos