Uses and attitudes of young people toward technology and mobile telephony

This paper aims at showing how young people are developing new and innovative ways of interacting using technology. Previous literature shows that technology adoption depends not only on the technology per se, but also on situational and contextual issues. Mobile telephony has been claimed to change young people's lifestyles, although only scarce empirical evidence exists. We have conducted an empirical study in which we first analyze the existence of differences in technology adoption, acquisition, and usage of technology and mobile telephony between young people in general and those that are online. We find that there are some significant differences in certain dimensions. Next, we carried out the same analysis differentiating between young people that assess themselves as technology-savvy and those that consider themselves inexpert in technology matters. We find that patterns of mobile phone usage in these two groups vary significantly along all analyzed dimensions.mobile telephony; Internet; technology adoption; uses and attitudes;

Mean-field Based Approaches to Pairing Correlations in Atomic Nuclei

The evolution of the pairing correlations from closed shell to middle shell nuclei is analyzed with a Finite Range Density Dependent interaction in the Sn isotopes. As theoretical approaches we use the Hartree-Fock-Bogoliubov, the Lipkin-Nogami, their particle number projected counterparts and the full variation after particle number projection method. We find that whereas all approaches succeed rather well in the description of the total energy they differ significantly in the pairing correlation content of the wave functions. The description of the evolution from the weak to the strong pairing regime is also approach dependent, specially at shell closure.Comment: 14 pages, 5 figure

A variational approach to approximate particle number projection with effective forces

Kamlah's second order method for approximate particle number projection is applied for the first time to variational calculations with effective forces. High spin states of normal and superdeformed nuclei have been calculated with the finite range density dependent Gogny force for several nuclei. Advantages and drawbacks of the Kamlah second order method as compared to the Lipkin-Nogami recipe are thoroughly discussed. We find that the Lipkin-Nogami prescription occasionally may fail to find the right energy minimum in the strong pairing regime and that Kamlah's second order approach, though providing better results than the LN one, may break down in some limiting situations.Comment: 16 pages, 8 figure

Constructive characterization of historical rammed-earth walls in Almohad fortresses in the ancient Reign of Seville

La mayor parte del patrimonio monumental andaluz construido en tierra corresponde a edificaciones militares levantadas en tapial entre los siglos XII al XV. Las del Antiguo Reino de Sevilla constituyen un grupo muy significativo, muchas de las cuales han sido objeto de intervenciones en las últimas décadas. En este trabajo se determinan, analizan y evalúan los principales rasgos técnicos y métricos de las fábricas de tapia de este ámbito espacial de época almohade, con un triple fin: aportar directrices que garanticen una restauración coherente y respetuosa con el bien patrimonial, avanzar en el conocimiento de los usos históricos de esta técnica constructiva y plantear hipótesis en relación a fábricas de adscripción cronológica incierta. Para ello, se implementa la metodología propuesta por los autores en trabajos precedente

Les paradoxes i la filosofia: tres visions contemporànies

Habitualment les paradoxes són caracteritzades com a enunciats aparentment falsos recolzats per arguments aparentment bons que parteixen de premisses que la majoria de la gent consideraria trivialment vertaderes. Aquest article ofereix una visió panoràmica de tres perspectives contemporànies de les paradoxes. Segons la concepció epistèmica, les paradoxes juguen un paper crucial en el desenvolupament de la ciència i mai no constitueixen proves correctes d’enunciats falsos. D’acord amb la concepció dialetheista, la conclusió d’alguns raonaments paradoxals és alhora vertadera i falsa, havent-hi, per tant, algunes contradiccions vertaderes (i falses). Finalment, la concepció mística entén les paradoxes recalcitrants (antinòmies) com a problemes irresolubles que mostren els límits del pensament humà. La darrera secció de l’article discuteix les paradoxes d’autoreferència, una família de paradoxes que comparteixen certs trets estructurals i que han tingut un impacte profund en el desenvolupament de la ciència al llarg del segle xx.Paraules clau: paradoxa, paradoxa verídica, paradoxa falsídica, antinòmia, dialetheisme, autoreferència, circularitat, inclosure. A paradox is usually described as an apparently false statement supported by an apparently good argument which departs from premises that most people would find trivially true. This survey article presents a brief overview of three different contemporary perspectives on paradoxes. According to the epistemic view, paradoxes play a crucial role in the progress of science and cannot be regarded as sound proofs of a false statement. According to the dialetheist view, the conclusion of some paradoxical reasonings is both, true and false, what means that there must be some true (and false) contradictions. Finally, the mystic view understands recalcitrant paradoxes (antinomies) as unsolvable problems which show the limits of human thought and cognition. The last section of this paper focuses on the paradoxes of self-reference, a family of paradoxes (sharing some structural features) which have had a deep impact in the development of science during the twentieth century.Keywords: paradox, veridic paradox, falsidic paradox, antinomy, dialetheism, selfreference, circularity, inclosure schema

Market bundling strategies in the horizontal portal industry

The arrival of the Internet offers opportunities for both incremental efficiency gains and complete industry redefinition, presenting new value propositions and hence leading to the emergence of new businesses and industries. One particular case is that of the horizontal portal industry, such portals being consistently the most visited sites on the Web. Nevertheless, despite ongoing market concentration, overall profitability remains low. In this paper we contend that, although the industry has great potential for value creation, value appropriation in such information-based businesses remains problematic. The only way to achieve it is through cross-market bundling; that is, portals selling their products packaged with Internet access and proprietary content through system competition. We support our claims with theoretical argument and empirical evidence, analyzing the information distribution value chain in its entirety.Portals; information goods; Internet advertising; Internet service providers; content provider;

The Simancas folder, a decimononic conspiration paradigm

Bajo este nombre se oculta una serie de documentos, confeccionados por Aviraneta como agente al servicio de la regente María Cristina, y que acabaron en manos del pretendiente al trono don Carlos en mayo de 1839 con el propósito de sembrar la discordia en su bando. De su análisis se obtenía la conclusión de que el jefe del ejército carlista, el general Maroto, estaba a las órdenes de esa logia.Hidden under this name are a series of documents written up by Aviraneta as agent at the service of Queen Regent Maria Cristina, and that, in May 1839 ended up in the hands of the pretender to the throne Don Carlos, with the purpose of sowing discord amongst his own bloc. From their analysis the conclusion was drawn that General Maroto, head of the Carlist army, was under the orders of the masonic lodg

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