Where are my followers? Understanding the Locality Effect in Twitter

Twitter is one of the most used applications in the current Internet with more than 200M accounts created so far. As other large-scale systems Twitter can obtain enefit by exploiting the Locality effect existing among its users. In this paper we perform the first comprehensive study of the Locality effect of Twitter. For this purpose we have collected the geographical location of around 1M Twitter users and 16M of their followers. Our results demonstrate that language and cultural characteristics determine the level of Locality expected for different countries. Those countries with a different language than English such as Brazil typically show a high intra-country Locality whereas those others where English is official or co-official language suffer from an external Locality effect. This is, their users have a larger number of followers in US than within their same country. This is produced by two reasons: first, US is the dominant country in Twitter counting with around half of the users, and second, these countries share a common language and cultural characteristics with US

P2P Based Architecture for Global Home Agent Dynamic Discovery in IP Mobility

Mobility in packet networks has become a critical issue in the last years. Mobile IP and the Network Mobility Basic Support Protocol are the IETF proposals to provide mobility. However, both of them introduce performance limitations, due to the presence of an entity (Home Agent) in the communication path. Those problems have been tried to be solved in different ways. A family of solutions has been proposed in order to mitigate those problems by allowing mobile devices to use several geographically distributed Home Agents (thus making shorter the communication path). These techniques require a method to discover a close Home Agent, among those geographically distributed, to the mobile device. This paper proposes a peer-topeer based solution, called Peer-to-Peer Home Agent Network, in order to discover a close Home Agent. The proposed solution is simple, fully global, dynamic and it can be developed in IPv4 and IPv6.No publicad

Is Content Publishing in BitTorrent Altruistic or Profit-Driven

BitTorrent is the most popular P2P content delivery application where individual users share various type of content with tens of thousands of other users. The growing popularity of BitTorrent is primarily due to the availability of valuable content without any cost for the consumers. However, apart from required resources, publishing (sharing) valuable (and often copyrighted) content has serious legal implications for user who publish the material (or publishers). This raises a question that whether (at least major) content publishers behave in an altruistic fashion or have other incentives such as financial. In this study, we identify the content publishers of more than 55k torrents in 2 major BitTorrent portals and examine their behavior. We demonstrate that a small fraction of publishers are responsible for 66% of published content and 75% of the downloads. Our investigations reveal that these major publishers respond to two different profiles. On one hand, antipiracy agencies and malicious publishers publish a large amount of fake files to protect copyrighted content and spread malware respectively. On the other hand, content publishing in BitTorrent is largely driven by companies with financial incentive. Therefore, if these companies lose their interest or are unable to publish content, BitTorrent traffic/portals may disappear or at least their associated traffic will significantly reduce

El mar como fuente de nuevos fármacos

Se describe el proceso de descubrimiento y desarrollo de nuevos fármacos por la empresa PharmaMar a partir de productos naturales de origen marino aislados de organismos de muy diversos tipos. Para ello, se describe el proceso del desarrollo del agente antitumoral Yondelis y algunos otros fármacos actualmente en fase de desarrollo como aplidinaUniversidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Analysis of searching mechanisms in hierarchical p2p based overlay networks

Proceedings of: The 6th Annual Mediterranean Ad Hoc Networking Workshop (Med Hoc Net 2007. (Corfu, Greece), June 2007This work presents a study of searching mechanisms in Peer-to-Peer (p2p) networks. The aim of this research line is to analyse cross-searching mechanisms that will allow the hierarchical interconnection of p2p networks. A set of relevant metrics for interconnection scenarios are defined to evaluate scalability, robustness and routing latency.This work has been partially supported by the European Union under the IST Content (FP6-2006-IST-507295) project and by the Madrid regional government under the Biogridnet (CAM, S-0505/TIC-0101) project.Publicad

Assessment of coercive persuasion: the Scale of Detection of Coercive Persuasion in Group Contexts (EDPC)

Comunicación presentada en las Jornadas Internacionales ICSA 2017 sobre Dinámicas sectarias y radicalizaciónCoercive persuasion refers to the control and manipulation developed by abusive groups, through different aggressive strategies that influence changes in the environment of its members, distorting cognition, altering emotions and generating significant psychosocial damage. It is a subtle, gradual and powerful force that affects around 500,000 Spanish victims of cultic groups (Cuevas & Perlado, 2011; Cuevas, 2012). Attaining power is one of the main goals of these groups, being the control and exploitation of the individual a part of the process. This derives to individuals giving up their own goals, freedom, material possessions, family and social networks, health or even life itself (Rodríguez-Carballeira, Saldaña, Almendros, Martin-Peña, Escartín, & Porrúa-Garcia, 2015). Such strategies are often implemented in a planned, graduate way and using deceit, difficulting that people who targeted are able to detect their evident aggressiveness and the generated damage. If there is an obvious shortage of instruments measuring psychological abuse in different fields (partner violence, harassment, bullying, etc.), the development of tools to assess the presence of such strategies in group contexts is even more scarce (Almendros, Gámez-Guadix, Carrobles & Rodríguez Carballeira, 2011). One of those assessment tools, the Interview for Detection of Coercive Persuasion (Cuevas & Canto, 2006) contains a wide range of coercive and abusive practises taking place within manipulative group. It has been applied in Spain in the forensic field in prosecutions of abusive groups (Dharma Tradición, Casa Yoga, Miguelianos, Revelance, etc.). The main objective of this recently validated tool (Cuevas, 2016) was to identify and provide evidences of the systematic application of coercive persuasion techniques on victims of abusive groups (Cuevas, 2012, 2016). Deriving from this instrument, sharing objectives, a new scale of 40 items and validated in Spanish population: the Scale of Detection of Coercive Persuasion in Group Contexts, or EDPC (Cuevas, 2016 ). To validate the EDPC, a Spanish sample of 134 people who identified themselves as having been abused or having been overly controlled by a group was selected. To assess criterion validity of the instrument, other different instruments (BSI MOS-SSS, RSE, SLEQ, ICP and EDS) were used. The group psychological abuse scale GPA (Chambers, Langone, Dole, & Grice, 1994), Spanish modified version (Almendros et al.,2004; Almendros et al., 2009) was used to assess the convergent validity of the instrument. The EDPC showed appropriate psychometric properties. In respect to reliability, the standardized Cronbach alpha coefficient reached a value of 0.97. The exploratory factorial analysis indicated the presence of a factor (coercive persuasion), establishing the suitability of a one-dimensional model. This scale aims to be useful in clinical and forensic fields, in order to assess the control and manipulation exercised in group contexts. Using it could be relevant to provide evidences of coercive groups practises, helping at trying to determinate the relationship between damage on the victims and the specific actions taken by groups or individuals who perform the abusive behaviors.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Dos poemas a la Virgen en dos manuscritos de la Biblioteca del Conde de Haro.

Sin resume

Measuring the bittorrent ecosystem: techniques, tips, and tricks

BitTorrent is the most successful peer-to-peer application. In the last years the research community has studied the BitTorrent ecosystem by collecting data from real BitTorrent swarms using different measurement techniques. In this article we present the first survey of these techniques that constitutes a first step in the design of future measurement techniques and tools for analyzing large-scale systems. The techniques are classified into macroscopic, microscopic, and complementary. Macroscopic techniques allow us to collect aggregated information of torrents and present very high scalability, able to monitor up to hundreds of thousands of torrents in short periods of time. Microscopic techniques operate at the peer level and focus on understanding performance aspects such as the peers¿ download rates. They offer higher granularity but do not scale as well as macroscopic techniques. Finally, complementary techniques utilize recent extensions to the BitTorrent protocol in order to obtain both aggregated and peer-level information. The article also summarizes the main challenges faced by the research community to accurately measure the BitTorrent ecosystem such as accurately identifying peers and estimating peers' upload rates. Furthermore, we provide possible solutions to address the described challenges.The research leading to these results has received funding from the European Union Seventh Framework Program (FP7/2007-2013) through the TREND NoE project (grant agreement no. 25774) and the Regional Government of Madrid through the MEDIANET project (S- 2009/TIC-1468).Publicad

Do best and worst innovative companies differ in terms of intellectual capital, knowledge and radicalness?

This paper differentiates “best innovative companies” from “worst innovative companies” and it takes into account three separate bodies of literature— intellectual capital, knowledge-based view, and innovation literatures. Based on a sample of 181 firms which belong to manufacturing and services industries, our findings show that best innovative performers companies (considering both financial and non-financial dimensions of innovation success) present systematically higher scores for all dimensions of intellectual capital: human, organizational and social capital) than worst innovation performers. Knowledge exchange and combination seems to be characteristic of most successful innovators, but no differences in systemic, tacit, complex and not observable knowledge have been found for these companies. Finally, regarding radicalness, firms with more innovation success provide new products or services that incorporates a new technology and new customer benefits (uniqueness), while firms with less innovation success laughs new products or services which are unfamiliar or difficult to understand by customers.Mobile-shopping