The NOBEL2 approach to resilience in future transport networks

IST project NOBEL2 results on resilience strategies for next-generation optical transport networks are presented, paving the way towards cost-effective, scalable and easy-to-maintain multi-service network architectures.Postprint (published version

A C-Terminal Protease-Resistant Prion Fragment Distinguishes Ovine “CH1641-Like” Scrapie from Bovine Classical and L-Type BSE in Ovine Transgenic Mice

The protease-resistant prion protein (PrPres) of a few natural scrapie isolates identified in sheep, reminiscent of the experimental isolate CH1641 derived from a British natural scrapie case, showed partial molecular similarities to ovine bovine spongiform encephalopathy (BSE). Recent discovery of an atypical form of BSE in cattle, L-type BSE or BASE, suggests that also this form of BSE might have been transmitted to sheep. We studied by Western blot the molecular features of PrPres in four “CH1641-like” natural scrapie isolates after transmission in an ovine transgenic model (TgOvPrP4), to see if “CH1641-like” isolates might be linked to L-type BSE. We found less diglycosylated PrPres than in classical BSE, but similar glycoform proportions and apparent molecular masses of the usual PrPres form (PrPres #1) to L-type BSE. However, the “CH1641-like” isolates differed from both L-type and classical BSE by an abundant, C-terminally cleaved PrPres product (PrPres #2) specifically recognised by a C-terminal antibody (SAF84). Differential immunoprecipitation of PrPres #1 and PrPres #2 resulted in enrichment in PrPres #2, and demonstrated the presence of mono- and diglycosylated PrPres products. PrPres #2 could not be obtained from several experimental scrapie sources (SSBP1, 79A, Chandler, C506M3) in TgOvPrP4 mice, but was identified in the 87V scrapie strain and, in lower and variable proportions, in 5 of 5 natural scrapie isolates with different molecular features to CH1641. PrPres #2 identification provides an additional method for the molecular discrimination of prion strains, and demonstrates differences between “CH1641-like” ovine scrapie and bovine L-type BSE transmitted in an ovine transgenic mouse model

G-réseaux dans un environnement aléatoire

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Multiple Class G-Networks with list-oriented deletions

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Réseaux généralisés multiclasses avec synchronisations cycliques

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Managing energy in a network of reconfigurable optical add/drop multiplexers

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Virtualizing and scheduling optical network infrastructure for emerging IT services

International audienceEmerging IT service providers that aim at delivering supercomputing power available to the masses over the Internet rely on high-performance IT resources interconnected with ultra-high-performance optical networks. To adjust the provisioning of the resources to end-user demand variations, new infrastructure capabilities have to be supported. These capabilities have to take into account the business requirements of telecom networks. This paper proposes a service framework to offer Internet service providers dynamic access to extensible virtual private execution infrastructures, through on-demand and in-advance bandwidth and resource reservation services. This virtual infrastructure service concept is being studied in the CARRIOCAS project and implemented thanks to the scheduling, reconfiguration, and virtualization (SRV) component. This entity handles the service requests, aggregates them, and triggers the provisioning of different types of resources accordingly. We propose to adapt to envisioned heterogeneous needs by multiplexing rigid and flexible requests as well as coarse or fine demands. The goal is to optimize both resource provisioning and utility functions. Considering the options of advanced network bandwidth reservations and allocations, the optimization problem is formulated. The impacts of the malleability factor are studied by simulation to assess the gain

Applying formal methods to PCEP: an industrial case study from modeling to test generation.

International audienceThis paper presents the experimental results in applying formal methods to an industrial protocol for constraint-based path computation, called Path Computation Element Communication Protocol (PCEP). The experiments include a number of major activities in model-based testing from modeling to test generation. From the PCEP specification defined by IETF (Internet Engineering Task Force), the functionalities of PCEP are divided into two parts: application and protocol. The protocol part of PCEP is then described in the IF (Intermediate Format) language which is based on communicating timed automata. A number of basic requirements are identified from the PCEP specification and then described as properties in IF. Based on these properties, the validation and verification of the formal specification are carried out using the IF toolset. Test cases are generated using an automatic test generation tool, called TestGen-IF, which uses partial state space exploration guided by test purposes. As a result, some errors and ambiguities have been found in the PCEP standard specification

Wired/Wireless Internet Communications: 9th IFIP TC 6 International Conference, WWIC 2011, Vilanova i la Geltrú, Spain, June 15-17, 2011. Proceedings

International audienceBook Front Matter of LNCS 664