Synthesis and reactivity of half-sandwich (η 5 -C 5 Me 5 )Ir(iii) complexes of a cyclometallated aryl phosphine ligand

Reaction of the Ir(iii) dimer [(η 5 -C 5 Me 5 )IrCl 2 ] 2 with PMeXyl 2 (Xyl = 2,6-C 6 H 3 Me 2 ), in the presence of the poorly coordinating base 2,2,6,6-tetramethyl piperidine, gives a chloride complex 1-Cl, resulting from hydrogen chloride elimination involving one of the phosphine benzylic hydrogen atoms and concomitant cyclometallation. Related compounds containing other halide or pseudohalide ligands, 1-Br, 1-Cl, 1-SCN, can be made, the latter featuring S-coordination of the ambidentate thiocyanate to the soft Ir(iii) Lewis acid centre, as suggested by IR data and demonstrated by X-ray crystallography. Hydride 2-H, and alkyl derivatives 3 (Me) and 4 (CH 2 SiMe 3 ) can also be prepared from 1-Cl and appropriate hydride and alkylating reagents. An interesting H/D exchange chemistry that occurs in the presence of CD 3 OD has been disclosed for 1-Cl, 1-Br and 2-H. For the halide derivatives, deuterium incorporation takes place into the methylene and methyl sites of their cyclometallated ligand, whereas for 2-H only the hydride and methylene (Ir-CH 2 ) protons participate in the exchange, which is strikingly accelerated by catalytic amounts of acids.Ministerio de Ciencia e Innovación CTQ2010-17476Consolider-Ingenio2010 CSD2007-0000Junta de Andalucia FQM-119, P09-FQM-483

Assembly and dynamics of propelling ferromagnetic colloids

Treballs Finals de Màster en Física dels Sistemes Complexos i Biofísica, Facultat de Física, Universitat de Barcelona. Curs: 2022-2023. Tutors: Gaspard Junot, Pietro TiernoActive colloids is a growing field of research that studies the emergent phenomena exhibited in systems of self-propelling particles as a result of the interactions between them that could not be observed if these components were isolated. These phenomena can be observed in a wide variety of systems. In this work, I show how a collection of oscillating colloidal rotors, or simply, shakers, immersed in a viscoelastic fluid, specifically, a solution of polyacrylamide (PAAM), can display this behaviour, forming complex zig-zag dynamic bands that grow linearly in time. I have investigated the dynamics of this band growth for two different PAAM concentrations, as well as the hydrodynamic flow around these shakers for both cases. This helps understanding the complex dynamics of these fluids, having implications in soft matter physics and microfluidics and in biophysic

An efficient confidentiality-preserving Proof of Ownership for deduplication

Data storage in the cloud is becoming widespread. Deduplication is a key mechanism to decrease the operating costs cloud providers face, due to the reduction of replicated data storage. Nonetheless, deduplication must deal with several security threats such as honest-but-curious servers or malicious users who may try to take ownership of files they are not entitled to. Unfortunately, state-of-the-art solutions present weaknesses such as not coping with honest-but-curious servers, deployment problems, or lacking a sound security analysis. In this paper we present a novel Proof of Ownership scheme that uses convergent encryption and requires neither trusted third parties nor complex key management. The experimental evaluation highlights the efficiency and feasibility of our proposal that is proven to be secure under the random oracle model in the bounded leakage setting. (C) 2015 Elsevier Ltd. All rights reserved

Analysis of Global Research on Malaria and Plasmodium vivax

Background: Malaria is one of the infectious diseases of greatest interest to the scientific community and of greatest concern to international health authorities. Traditionally, the focus has been on Plasmodium falciparum, the parasite that causes the most severe form of the disease in Africa. However, in the last twenty years, the Plasmodium vivax parasite, responsible for a large number of cases in Latin America, the Middle East, South and Southeast Asia, the Horn of Africa, and Oceania, has also generated enormous interest due, among other things, to the published evidence that it can cause severe malaria. Methods: In this paper, the international scientific publication on malaria and P. vivax has been analyzed using the Scopus database to try to define global trends in this field of study. Results: It has been shown that events such as the emergence of resistance to certain drugs can break a trend. The important role of non-malaria-endemic countries such as the USA or Switzerland in malaria research is also evident. Conclusions: International cooperation will be essential for the eradication of the disease. Moreover, in this sense, the general vision given by the bibliometric analysis of malaria caused by P. vivax is fundamental to paint the picture regarding the current situation and encourage international cooperation and control efforts

Aprendizaje léxico de una lengua extranjera mediante una metodología basada en la adquisición de contenidos

Este trabajo se propone refl exionar sobre una serie de aspectos relacionados con las últimas investigaciones centradas en el aprendizaje léxico en una lengua extranjera y analizar cómo todos estos aspectos pueden ser integrados mediante la aplicación de la metodología basada en contenidos con la fi nalidad de incrementar el repertorio léxico de los alumnos de forma natural, signifi cativa y duradera. The aim of this paper is to refocus attention on some aspects connected to the latest research on lexical learning in a foreign language and to analyze how all those basic and fundamental aspects can be integrated by using Content-based Instruction in order to improve our students’ lexicon in a natural, meaningful way

Analytic surveillance: Big data business models in the time of privacy awareness

 Massive data collection and analysis is at the heart of many business models today. New technologies allow for fine-grained recommendation systems that help companies make accurate market predictions while also providing clients with highly personalized services. Because of this, extreme care must be taken when it comes to storing and managing personal (often highly sensitive) information. In this paper we focus on the influence of big data management in media business content platforms, mainly in well-known OTT (Over the Top) services. In addition, we comment on the implications of data management in social networks. We discuss the privacy and security risks associated with this novel scenario, and briefly comment on tools that aid in securing the privacy of business intelligence within this context

Statistical measure of complexity for quantum systems with continuous variables

The Fisher-Shannon statistical measure of complexity is analyzed for a continuous manifold of quantum observables. It is probed then than calculating it only in the configuration and momentum spaces will not give a complete description for certain systems. Then a more general measure for the complexity of a quantum system by the integration of the usual Fisher-Shannon measure over all the parameter space is proposed. Finally, these measures are applied to the concrete case of a free particle in a box.Comment: 6 pages, 5 figures. Published versio

U+F Social Network Protocol: Achieving interoperability and reusability between Web Based Social Networks

Proceeding of the: 11th International Conference on Trust, Security and Privacy in Computing and Communications (TrustCom 2012), Liverpool, UK, 25-27 June 2012Along the time many Web Based Social Networks (WBSNs) have appeared, but not all of them offer the same services. Users may use multiple WBSNs to satisfy their requirements. Besides, operations such as the creation of accounts or the establishment of groups, are repeated in all of them, being a tedious issue. To address this matter, this paper proposes a protocol, based on the UMA core protocol and the FOAF project, to attain interoperability and reusability of resources, identity data and access control policies across different WBSNs. Moreover, an evaluation and a security analysis are presented.Publicad

Diseño de un protocolo para el envío de notificaciones de denuncias por hechos de circulación al vehículo a través de tecnologías ITS

Actas de: XII Congreso Español de Sistemas Inteligentes de Transporte, Madrid, 24 al 26 de abril de 2012Los mecanismos actualmente existentes para la notificación consiguen que ésta llegue a su destinatario varios días después a la comisión del hecho. Esta circunstancia juega en contra del potencial educativo de la sanción, el cual crece con la inmediatez. El marco tecnológico que plantean los ITS permite atisbar un nuevo canal de notificación, directo al vehículo. De esta forma, el conductor podría recibir dicho mensaje con máxima rapidez, posibilitando un potencial cambio en su conducta. En este trabajo se propone el diseño de un protocolo de intercambio de datos entre un vehículo y la infraestructura de comunicaciones ITS. Además, se analiza el cumplimiento de los requisitos legales por parte del protocolo, así como sus costes computacionales y de red considerando una plataforma ITS comercial. En este último aspecto es imprescindible tener en cuenta los costes de la aplicación de técnicas criptográficas que serán necesarias para garantizar la integridad, confidencialidad y autenticidad de los datos en juego.Este trabajo ha sido realizado en el marco del proyecto E-SAVE, subvencionado por el Ministerio de Ciencia e Innovación (referencia TIN2009-13461).No publicad