Evaluation and interoperatibility of security protocols and arquitectures

During the last years, use of security protocols has increased significantly. Protection of the communications had been provided by security protocols and architectures, however some problems have appeared, revealing that the potential expansion of ICT can be limited if some interoperability problems are not solved. Our group have created and implemented a new methodology in order to reduce the interoperability problems of the implementations of security protocols and architectures. This methodology develops a completed conformance evaluation with the particular security standard and furthermore realizes a performance analysis of the more important parameters for the development of security protocols

Authentication System based on ID-Network Smart Cards (ID-NSCards) for Critical Environments

Researchers in the Information Security area in the Carlos III University of Madrid (Spain) are interested to exploit the potential of an emerging technology: network smart cards. These new devices have a number of additional advantages for communications security in networked systems, comparing with the traditional smart cards. These interesting features could be applied to individuals identification procedures in environments where critical tasks or operations take place. The required collaboration would be focused in the development and implementation of an authentication system for critical environments based on this technology

A review of ordering phenomena in iron-silicon steels

Silicon steel is an industrially-desired alloy of iron and silicon, characterised by soft magnetic properties, low eddy-current losses, and low magnetostriction. Silicon steels have narrow hysteresis cycles, making them particularly advantageous in applications using electromagnetic fields, such as transformers, generators, electric motor cores, and few other components in industry. Despite its incontestable industrial value, there is not much agreement on the atomic structure of silicon steel. Gaining better understanding of e.g. ordering processes in Fe-Si alloys could not only explain their magnetic properties, but also open opportunities to reduce their weaker characteristics, such as brittleness that adversely affects silicon steel workability and its associated high production costs. This review summarises the state-of-the-art knowledge about ordering in silicon steel and describes the most relevant experimental techniques used for studying its microstructure. In addition, the process of building the iron rich part of the Fe-Si phase diagram is explained. Lastly, the influence of order on the alloy's magnetic and mechanical properties is illustrated

Numerical Simulations of Gamma-Ray Burst Explosions

Gamma-ray bursts are a complex, non-linear system that evolves very rapidly through stages of vastly different conditions. They evolve from scales of few hundred kilometers where they are very dense and hot to cold and tenuous on scales of parsecs. As such, our understanding of such a phenomenon can truly increase by combining theoretical and numerical studies adopting different numerical techniques to face different problems and deal with diverse conditions. In this review, we will describe the tremendous advancement in our comprehension of the bursts phenomenology through numerical modeling. Though we will discuss studies mainly based on jet dynamics across the progenitor star and the interstellar medium, we will also touch upon other problems such as the jet launching, its acceleration, and the radiation mechanisms. Finally, we will describe how combining numerical results with observations from Swift and other instruments resulted in true understanding of the bursts phenomenon and the challenges still lying ahead.Comment: 14 Pages, Journal of High Energy Astrophysics for the dedicated issue: "Swift: Ten Years of Discovery", in pres

Crystal-chemistry and short-range order of fluoro-edenite and fluoro-pargasite: a combined x-ray diffraction and ftir spectroscopic approach

In this study we address the crystal-chemistry of a set of five samples of F-rich amphiboles from the Franklin marble (USA), using a combination of microchemical (EMPA), SREF, and FTIR spectroscopy methods. The EMPA data show that three samples fall into the compositional field of fluoro-edenite whereas two samples are enriched in high-charged C cations, and must be classified as fluoro-pargasite. Mg is by far the dominant C cation, Ca is the dominant B cation (with BNa in the range 0.00-0.05 apfu, atoms per formula unit), and Na is the dominant A cation, with A0 (vacancy) in the range 0.07-0.21 apfu; WF is in the range 1.18-1.46 apfu. SREF data show that: TAl is completely ordered at the T(1) site; the M(1) site is occupied only by divalent cations (Mg and Fe2+); CAl is disordered between the M(2) and M(3) sites; ANa is ordered at the A(m) site, as expected in F-rich compositions. The FTIR spectra show a triplet of intense and sharp components at ~ 3690, 3675, and 3660 cm-1, which are assigned to the amphibole, and the systematic presence of two very broad absorptions at 3560 and 3430 cm-1. These latter are assigned, on the basis of polarized measurements and FPA imaging, to chlorite-type inclusions within the amphibole matrix. Up to eight components can be fitted to the spectra; band assignment based on previous literature on similar compositions shows that CAl is disordered over the M(2) and M(3) sites, thus supporting the SREF conclusions based on the bond distance analysis. The measured frequencies are typical of O-H groups pointing toward Si-O(7)-Al tetrahedral linkages, thus allowing to characterize the SRO (short-range-order) of TAl in the double chain. Accordingly, the spectra show that in the fluoroedenite/pargasite structure, the T cations, Si and Al, are ordered in such a way that Si- O(7)-Si linkages regularly alternate with Si-O(7)-Al linkages along the double chain.Comment: 38 pages, 10 figures - in press. Mineralogical Magazine, special issue for the international year of crystallography (2013) in pres

Functional characterization of TasA and TapA in the formation of the amyloid fiber in Bacillus subtilis

Introduction Functional amyloids are a very heterogeneous family of amyloid proteins widespread in nature, from humans to bacteria. Unlike their “pathogenic” relatives, implicated in several neurodegenerative diseases, functional amyloids play important roles in several biological processes. In Bacillus subtilis, the protein TasA forms amyloid-like fibers that serve as a scaffold for the rest of the components of the extracellular matrix. Along with TasA, the auxiliary protein TapA promotes and accelerates TasA fiber assembly. Most amyloid proteins contain regions within their sequence in which their aminoacid composition make them prone to aggregation. However, the sequence determinants in TasA or TapA involved in the assembly of the amyloid fiber, its structure and function still remains elusive. Objectives To identify and characterize regions of TasA or TapA important for amyloid fiber assembly and functionality in Bacillus subtilis biofilms. Materials & methods An in silico study was performed in order to define amyloidogenic regions within TasA and TapA sequences. This analysis revealed several regions of interest and was followed by in vitro experiments using synthetic peptides corresponding to the analyzed regions. We used several biophysical techniques in combination with transmission electron microscopy to study their possible amyloid properties. Results Of the predicted amyloidogenic regions of TasA, only two polymerized with enrichment of beta-sheets, characteristic of amyloid proteins. A similar behavior was found in a sequence of the N-terminal half of TapA, which has been previously demonstrated to be determinant in the functionality of TapA. Conclusion Our findings support the utility of the in silico prediction for the search of amyloidogenic domains in proteins. The aggregative properties of all peptides and the additional amyloid-like features of some of them are suggestive of their relevance in the amyloid properties of TasA and suggest in some cases, their putative implication in the TasA-TapA interaction.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Components Interoperability through Mediating Connector Patterns

A key objective for ubiquitous environments is to enable system interoperability between system's components that are highly heterogeneous. In particular, the challenge is to embed in the system architecture the necessary support to cope with behavioral diversity in order to allow components to coordinate and communicate. The continuously evolving environment further asks for an automated and on-the-fly approach. In this paper we present the design building blocks for the dynamic and on-the-fly interoperability between heterogeneous components. Specifically, we describe an Architectural Pattern called Mediating Connector, that is the key enabler for communication. In addition, we present a set of Basic Mediator Patterns, that describe the basic mismatches which can occur when components try to interact, and their corresponding solutions.Comment: In Proceedings WCSI 2010, arXiv:1010.233