Beamforming and Multiuser Detection in CDMA Systems with External Interferences

Multiuser detection has been investigated to mitigate the near-far effect in CDMA systems. Antenna arrays have been shown to provide spatial diversity and cancel undesired signals. In this paper we consider the synergy of both multiuser detection and antenna arrays for the base station of a CDMA system. The receiver we proposed consists of the known multiuser decorrelator, which cancels multiple-access interferences followed by a beamformer for each user, which cancels the external interferences. This receiver adds an extra branch to the decorrelator. This additional branch, corresponding to a fictitious user with an unused code and zero power, allows to estimate the external interference signal subspace and compute a suitable beamforming weight-vector that cancels the external interferences. The receiver is also extended to the asynchronous case and all of this without any training signal or any a priori spatial information.Peer ReviewedPostprint (published version

Blind multiuser adaptive combining for asynchronous cdma systems

This paper presents a novel technique to globally estimate and track the direction of arrival (DOA) of different users in an asynchronous CDMA system. The estimates are obtained exploiting the temporal structure of CDMA signals. No training signal nor a priori spatial information is required. The necessary information is extracted directly from the received signals. The proper combining of the overall information present at the receiver after the despreading, jointly with an Eigenvalue Decomposition (EVD), let as estimate the generalized steering vector for each user. Furthermore, a direct iteration method is introduced in our scheme in order to make the array robust to channel variations and to reduce the computational load of the EVD required for each user.Peer ReviewedPostprint (published version

Blind multi-user combining at the base station for asynchronous CDMA systems

This paper studies the potential benefits of antenna arrays in cellular CDMA communications and proposes a powerful scheme to undertake the array processing at the base station in CDMA mobile systems. The proposed technique exploits the temporal structure of CDMA signals. The necessary information is extracted directly from the received signals, thus no training signal orPeer ReviewedPostprint (published version

Good practices in school to educate critical citizens: the youth parliament programme from the perspective of secondary school teachers in training

ERPA International Congresses on Education 2018This paper refers to the European project Erasmus + ELEF (European Learning Environment Formats for Citizenship and Democracy, Reference number 580426). The aim of this project is to develop, implement, evaluate and replicate democratic and innovative learning environments (good practices) in both educational institutions and informal and community learning environments. In this context, over the course of a year, a number of experiences considered relevant have been selected, which constitute the sample of this research on good practices. This contribution presents the educational programme “Youth Parliament”. This is a project with a long history and whose main objective is to train responsible citizens, with the collaboration of various educational agents. The evaluation carried out by the Secondary Education teachers in training on the potentialities and limitations of the programme is shown, based on the experiences carried out in the participating educational centres during the academic year 2016-2017

Sobre el orden de palabras en español.

Sin resume

Datives in Constructions with Unaccusative Se

In this talk I argue that in Spanish there is a type construction, involving a verb with the unaccu-sative seclitic and a dative, where the dative is in fact the external argument, which renders the construction comparable to a transitive structure (in the well-established unaccusative-transitive alternation). A number a tests and criteria are reviewed to support the external argument status of the dative (which in fact can be assimilated to the status of locatives and datives with some impersonal verbs, see Fernández Soriano 1999). These are: unmarked word order, raising and binding. On the other hand, there is also evidence for the non externalized status of other, internal, argument: impossibility of anaphor binding, possibility of being a bare NP, inability to control, among others. I conclude that in this constructions the dative is an instance of quirky case.En aquesta xerrada defenso que en castellà hi ha un tipus de construcció, que conté un verb amb la marca sed'inacusatiu i un datiu, on el datiu és, de fet, l'argument extern, cosa que fa aquesta construcció comparable a una estructura transitiva (dins l'alternança ben coneguda inacusatiu-transitiu). S'hi revisen tots de proves i criteris que donen suport al caràcter d'argument extern del datiu (que, de fet, és assimilable a l'estatus dels locatius i datius amb alguns verbs impersonals, vegeu Fernández Soriano 1999). Com a indicis, tenim: ordre de mots no marcat, elevació i lligam. D'altra banda, hi ha també indicis del caràcter no externalitzat de l'altre argument, l'intern: impossibilitat de lligam d'anàfores, possibilitat de ser un SN nu, incapacitat de controlar, entre d'altres. La conclusió és que en aquestes construccions el datiu és un exemple de cas capri-ciós (quirky case)

La naturalització de la Fenomenologia

En aquest article, s'hi pretén mostrar quines són les propostes actuals principals sobre la possibilitat d'establir una relació intel·ligible i fructífera entre la fenomenologia filosòfica i la neurociència cognitiva, i alhora assenyalar un dels problemes importants que presenta la proposta que, segons el meu parer, té més plausibilitat i possibilitat d'èxit.This paper tries to make out which are the main current proposals about the possibility of an understandable fruitful relation between philosophical phenomenology and cognitige neuroscience, while at the same time pointing out a key difficulty in the proposal which, to my mind, is the most plausibly successful

Inhibición de la apoptosis y acúmulo de alteraciones genéticas en la progresión metastásica del cáncer de mama : variabilidad genética y selección poblacional /

Consultable des del TDXTítol obtingut de la portada digitalitzadaEn un grupo de tumores de mama se decidió estudiar si la pérdida de función de la proteína Bax podía ser debida a la existencia de mutaciones frameshift. Los resultados obtenidos sugieren que en cáncer de mama, las mutaciones del gen bax no serían críticas para la carcinogénesis y el proceso de progresión tumoral. Este tipo de mutaciones sólo se han detectado en tumores con inestabilidad de microsatélites, por lo tanto decidimos estudiar cual era la incidencia de este tipo de alteración en nuestro grupo de tumores, encontrando que un 11,6 % eran inestables. La inestabilidad detectada quedó delimitada a las secuencias que afectaban a dinucleótidos, no se encontró ninguna alteración en las secuencias de mononucleótidos analizadas. Se encontró una asociación estadísticamente significativa entre la existencia de inestabilidad de microsatélites y la pérdida de apoptosis observada en los tumores. La mayor supervivencia celular resultado de la pérdida de apoptosis podría favorecer la existencia de este tipo de alteración en los tumores. Para corroborar si la pérdida de apoptosis se podía asociar a la existencia de inestabilidad de forma genérica en los tumores de mama, se decidió estudiar si la sobreexpresión de las proteínas antiapoptóticas Bcl-2 y Bcl-xL era capaz de inducir un acúmulo de alteraciones genéticas, y el efecto que las mismas podían tener sobre el proceso de progresión tumoral. Al analizar el daño genómico en las líneas transfectadas con respecto a la línea parental, los transfectantes con genes antiapotóticos tenían un GDF mayor que los transfectantes con el gen control. Por lo tanto, la inhibición de la apoptosis era capaz de inducir un aumento en el número de alteraciones genéticas detectables por AP-PCR, contribuyendo así a la inestabilidad genética que caracteriza a las células tumorales. El análisis filogenético de las líneas transfectadas, con respecto a la línea parental indicaba que los transfectantes con genes antiapoptóticos tenían un parentesco más cercano, originado por una mayor similitud de las alteraciones genéticas, mientras que las alteraciones de la línea control presentaban un mayor grado de divergencia. El análisis de los resultados mediante un programa de clusters mostraba la presencia de 3 zonas donde el tipo de alteraciones presentes en las líneas transfectadas con los genes antiapoptóticos y con el gen control son divergentes. Al analizar el GDF de las diferentes variantes tumorales y metastáticas, tomando como referencia las líneas derivadas de la generación anterior los resultados indicaban que a medida que avanzaba el proceso de progresión tumoral, el número de alteraciones genéticas detectadas iba en aumento, tanto a nivel de tumores como de metástasis. Este aumento de inestabilidad se correlaciona con una mayor capacidad tumorigénica y metastática de las líneas celulares. Sin embargo, las variantes celulares con mayor capacidad tumorigénica y metastática no son las que presentan un mayor número de alteraciones. Estos resultados indicarían que sólo una parte de las alteraciones detectadas son responsables del fenotipo tumoral y metastático. Por lo tanto quizá las alteraciones detectadas en el control son más aleatorias y sin repercusión biológica, mientras que la sobreexpresión de moléculas antiapopotóticas da de entrada una ventaja de crecimiento, con lo cual la célula es capaz de progresar con un menor número de alteraciones genéticas, pero de mayor efectividad biológica. El daño genómico de las metástasis con diferente organoespecificidad mostraba un comportamiento diferencial, tanto en relación con el número como la naturaleza de las mismas, en función del órgano de origen. Finalmente, decidimos estudiar si la organoespecificidad de las metástasis podía ser debida a cambios en la expresión génica. Estos estudios se hicieron utilizando la técnica de microarrays. Una vez hecho el análisis estadístico se determinaron genes asociados a actividad metastática, que serían aquellos genes que aparecían diferencialmente expresados en las cuatro variantes metastáticas analizadas. También se identificaron los genes cuya expresión se modificaba conjuntamente en las dos metástasis ganglionares, y aquellos cuya expresión diferencial se asociaba a la presencia de metástasis ósea.We studied in a group of breast cancer samples if the loss of function of Bax protein was due to frameshift mutations. Our results show that in breast cancer, bax mutations are not relevant for tumoral progression. This kind of alterations was only found in tumors with microsatellite instability, so we decide to know the incidence of this kind of instability in our samples, the result was that 11,6 % of the tumors show instability. The instability was detected only in dinucleotide sequences, no alteration was found in the mononucleotides analyzed. There was an association, with stadistic significance, between the microsatellite instability and the loss of apoptosis detected in the tumors. Loss of apoptosis can promote survival and this could favour the induction of this kind of alteration in tumors. To confirm if there is an association between loss of apoptosis and genetic instability in breast cancer cells, we studied if the overexpression of the antiapoptotic proteins Bcl-2 and Bcl-xL was able to induce an accumulation of genetic alterations, and which will be the effect of this alterations in tumor progression. The analysis of the genomic damage in transfected cells with regard to the parental line, show that cell lines overexpressing antiapoptotic genes have a greater GDF than control cells. So, the inhibition of apoptosis can induce an increase in the amount of genetic alterations detectable by AP-PCR, and can contribute to the genetic instability of tumoral cells. The philogenetic analysis of the transfected cells with regard to the parental line show that cell lines overexpressing antiapoptotic genes have a nearest relationship, due to a greater similarity between the genetic alterations. On the other hand, the alterations of the control cells are more divergent. The analysis of these results with a cluster software shows the existence of at least 3 regions with different kind of genetic alterations between cells transfected with antiapoptotic genes and control cell. The GDF analysis in the tumoral and metastatic variants, taking as a reference the cell lines derived from the previous generation, show that with the advance of tumor progression, there was an increase in the number of genetic alterations, both, in tumors and in metastasis. This increase in the detected instability correlates with a greater tumorigenic and metastatic ability of the cell lines. Nevertheless, the cell variants with a greater tumorigenic and metastatic ability show less genetic alterations. These results indicate that only some of the genetic alterations detected are responsible of the tumoral and metastatic phenotype. So, perhaps the alterations detected in the control cells are more random, and without biological significance. On the other hand, the overexpression of antiapoptotic genes could give the cells and inicial advantage, so the tumoral cell will be able to progress with less alterations, but more eficient ones. The genomic damage in metastasis with different organospecificity show a differential behaviour with regard to the organ of origin both, with regard to the number and the nature of the genetic alterations detected. Finally, we studied if the organospecificity of metastasis could be due to changes at gene expression level. These experiments have been performed using microarrays. After the analysis of the data, we have determined wich genes were associated to the metastatic ability of the cells. These genes will be those whose expression was modified simultaneously in the 4 metastatic variants studied. We have also determined wich genes were differentially expressed in lymh node metastasis, and those that were associated to bone metastasis