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;

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

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

SINGLE FACTOR STOCHASTIC MODELS WITH SEASONALITY APPLIED TO UNDERLYING WEATHER DERIVATIVES VARIABLES

This paper estimates single factor stochastic models describing daily air temperature behaviour. We modify classical financial models to reflect temperature seasonality and fit them to a time series representing temperatures in Spain. The estimated models are used in Montecarlo simulations to obtain heating and cooling degree-days, which are used as an underlying reference in weather derivatives. The final goal of this work is to obtain an insight into weather derivative valuation, and so making it easier to manage economic activity risks closely related to temperature (i.e. oil, gas and electricity prices and volumes). En este trabajo se estiman modelos estocásticos unifactoriales que describen elcomportamiento de la temperatura del aire de un índice representativo de la Españapeninsular. Los modelos más utilizados en finanzas se adaptan para incorporar elcomportamiento estacional de la variable temperatura. El objetivo de este trabajo es obtenerresultados que permitan avanzar en la valoración de activos derivados sobre climatología.Este tipo de derivados permiten gestionar riesgos de la actividad económica estrechamenterelacionados con la temperatura (por ejemplo, los riesgos de precio y volumen del gas y laelectricidad). Con los modelos estimados se realiza un ejercicio de simulación de Montecarlopara obtener los grados día frío y los grados día calor que son las referencias subyacentes enlos contratos de meteorología.Grados Día Frío, Energía, Grados Día Calor, Estacionalidad, Modelos estocásticos y Derivados de la meteorología. Cooling Degree-days, Energy, Heating Degree-days, Seasonality, Stochastic Models, Weather Derivatives.

CIO herds and user gangs in the adoption of open source software

Open Source Software (OSS) has received wide attention from the research community, analyzing both the innovation process of software development by distributed and unrelated teams, and the market dynamics at play between "free" and proprietary software. Up until now, OSS adoption has been irregular, although it seems to be breaking the dominance of existing players in some market segments. In this paper, we contend that due to the particularities of its development process, traditional ways of explaining IT adoption -rational decision making, technology diffusion models, and the psychology of the decision maker- are insufficient to explain the case of OSS diffusion. We believe that the existence of a strong and diffused development community leads to a new role of the user community, as both are intertwined. In addition, new concerns for social corporate responsibility and welfare create a new context, in which "user gangs" may exert some degrees of pressure on the IT decision maker. By analyzing some significant cases we depict under what conditions significant OSS adoption may unfold, showing that in two of the cases studied user gangs play a significant role. The resulting preliminary framework will inform future work, in which we aim at validating the emerging insights gained in this research.Open source software; IT adoption; user communities; CIO herding;

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

3-Amino-2-Piperidinequinoline A Novel Natural Product-Inspiried Synthetic Compound with Antimalarial Activity

Malaria afflicts about 500 million people worldwide thus causing significant global economic toll. The drugs available to treat the disease are rapidly losing their efficacy because of widespread prevalence of drug resistant parasites. Thus there is an urgent need to discover novel malaria therapeutics. This research is focused on to study the properties of a novel naturallike synthetic scaffold and analyze its selectivity, and cellular mechanism of action in Plasmodium falciparum. We have identified a novel compound, 3-amino-2-piperidinequinoline (APQ), which we termed UCF401. APQ demonstrated IC[sub50] at submicromolar concentrations against Plasmodium falciparum using the SYBR Green-I fluorescence assay measuring cellular proliferation. This compound also demonstrated low cytotoxicity against the NIH3T3 and HEPG2 cells using MTS assays, showing an IC50 of 174 [micro]M and 125 [micro]M respectively, suggesting of excellent selectivity. We evaluated the compliance of APQ with Lipinski\u27s parameters and determined the in vitro physicochemical profiles of the compound. Our results show that APQ is a Lipinski parameter compliant and has good physicochemical properties. The cellular mechanism of action of APQ was characterized through the assessment of the effects of the compound at different stages of the parasite\u27s intraerythrocytic life cycle. This assay was done by treating a synchronized cell line with the compound at 5X the IC50 value and then imaging the cells at 12-hour intervals. We found that APQ arrests parasite development at the trophozoite stage. In addition we determined that APQ is parasitocidal after a 96 h exposure. These results demonstrate that APQ can be considered as a validated hit and/or early lead

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