Towards a Framework for the Extension and Visualisation of Cyber Security Requirements in Modelling Language

Every so often papers are published presenting a new extension for modelling cyber security requirements in Business Process Model and Notation (BPMN). The frequent production of new extensions by experts belies the need for a richer and more usable representation of security requirements in BPMN processes. In this paper, we present our work considering an analysis of existing extensions and identify the notational issues present within each of them. We discuss how there is yet no single extension which represents a comprehensive range of cyber security concepts. Consequently, there is no adequate solution for accurately specifying cyber security requirements within BPMN. In order to address this, we propose a new framework that can be used to extend, visualise and verify cyber security requirements in not only BPMN, but any other existing modelling language. The framework comprises of the three core roles necessary for the successful development of a security extension. With each of these being further subdivided into the respective components each role must complete

A 3D Security Modelling Platform for Social IoT Environments

Social IoT environment comprises not just smart devices, but also the humans to interact with these IoT devices. The benefits of such system are overshadowed by the issues of cyber security. A new approach is required for us to understand the security implication under such dynamic environment, while taking both the social and technical aspects into consideration. This paper proposed a 3D security modelling platform that can capture and model security requirements in Social IoT environment. The modelling process is graphical notation based, working as a security extension to Business Process Model and Notation. Still, it utilises the latest 3D game technology thus the security extensions are generated through the third dimension. In this way, the introduction of security extensions will not increase the complexity of the original SIoT scenario, while keeping all the key information in the same platform. Together with the security ontology we have proposed, these comprehensive security notations created a unique platform that aiming at addressing the ever complicated security issues in SIoT envorinment

Flodoard of Rheims and the Historiography of the Tenth-Century West

Flodoard of Rheims is one of the most important authors of tenth-century Europe, and the only contemporary historian to document the momentous struggles between kings and nobles in Francia in the wake of the demise of the Carolingian Empire. Flodoard’s era stands at the center of major historiographical debates concerning the nature of political and social change and the origins of European institutions. Yet, despite his singularity, his substantial histories have received little attention from scholars examining the profound transformations of the period. Exploring this discrepancy, this article offers an overview of Flodoard’s career and reviews how his histories have been invoked in some of the great scholarly debates about tenth-century Europe. It further proposes to recontextualize Flodoard and to reread his histories from the bottom up in order to gain a subtler understanding of how one contemporary perceived and represented the dramatic events and changes taking place around him

Pb(II) Induces Scramblase Activation and Ceramide-Domain Generation in Red Blood Cells

The mechanisms of Pb(II) toxicity have been studied in human red blood cells using confocal microscopy, immunolabeling, fluorescence-activated cell sorting and atomic force microscopy. The process follows a sequence of events, starting with calcium entry, followed by potassium release, morphological change, generation of ceramide, lipid flip-flop and finally cell lysis. Clotrimazole blocks potassium channels and the whole process is inhibited. Immunolabeling reveals the generation of ceramide-enriched domains linked to a cell morphological change, while the use of a neutral sphingomyelinase inhibitor greatly delays the process after the morphological change, and lipid flip-flop is significantly reduced. These facts point to three major checkpoints in the process: first the upstream exchange of calcium and potassium, then ceramide domain formation, and finally the downstream scramblase activation necessary for cell lysis. In addition, partial non-cytotoxic cholesterol depletion of red blood cells accelerates the process as the morphological change occurs faster. Cholesterol could have a role in modulating the properties of the ceramide-enriched domains. This work is relevant in the context of cell death, heavy metal toxicity and sphingolipid signaling.AGA was a predoctoral student supported by the Basque Government and later by the University of the Basque Country (UPV/EHU). This work was also supported in part by grants from the Spanish Government (FEDER/MINECO BFU 2015-66306-P to F.M.G. and A.A.) and the Basque Government (IT849-13 to F.M.G. and IT838-13 to A.A.), and by the Swiss National Science Foundation

Ras GTPase activating (RasGAP) activity of the dual specificity GAP protein Rasal requires colocalization and C2 domain binding to lipid membranes

Rasal, belonging to the GAP1 subfamily of Ras GTPase-activating proteins (RasGAPs) with dual RasGAP/RapGAP specificity, is epigenetically silenced in several tumor types. Surprisingly, the isolated protein has GAP activity on Rap but not on Ras. Its membrane recruitment is regulated by interaction with calcium and lipids, which simultaneously induces its RasGAP activity through a yet unknown mechanism. Here we show that the interaction of Rasal with membranes induces Rasal RasGAP activity by spatial and conformational regulation, although it does not have any effect on its RapGAP activity. Not only is colocalization of Rasal and Ras in the membrane essential for RasGAP activation, but direct and Ca-dependent interaction between the tandem C2 domains of Rasal and lipids of the membrane is also required. Whereas the C2A domain binds specifically phosphatidylserine, the C2B domain interacts with several phosphoinositol lipids. Finally we show, that similar to the C2 domains of synaptotagmins, the Rasal tandem C2 domains are able to sense and induce membrane curvature by the insertion of hydrophobic loops into the membrane