Computing Delay-Constrained Least-Cost Paths for Segment Routing is Easier Than You Think

With the growth of demands for quasi-instantaneous communication services such as real-time video streaming, cloud gaming, and industry 4.0 applications, multi-constraint Traffic Engineering (TE) becomes increasingly important. While legacy TE management planes have proven laborious to deploy, Segment Routing (SR) drastically eases the deployment of TE paths and thus became the most appropriate technology for many operators. The flexibility of SR sparked demands in ways to compute more elaborate paths. In particular, there exists a clear need in computing and deploying Delay-Constrained Least-Cost paths (DCLC) for real-time applications requiring both low delay and high bandwidth routes. However, most current DCLC solutions are heuristics not specifically tailored for SR. In this work, we leverage both inherent limitations in the accuracy of delay measurements and an operational constraint added by SR. We include these characteristics in the design of BEST2COP, an exact but efficient ECMP-aware algorithm that natively solves DCLC in SR domains. Through an extensive performance evaluation, we first show that BEST2COP scales well even in large random networks. In real networks having up to thousands of destinations, our algorithm returns all DCLC solutions encoded as SR paths in way less than a second

The positive impacts of Real-World Data on the challenges facing the evolution of biopharma.

Demand for healthcare services is unprecedented. Society is struggling to afford the cost. Pricing of biopharmaceutical products is under scrutiny, especially by payers and Health Technology Assessment agencies. As we discuss here, rapidly advancing technologies, such as Real-World Data (RWD), are being utilized to increase understanding of disease. RWD, when captured and analyzed, produces the Real-World Evidence (RWE) that underpins the economic case for innovative medicines. Furthermore, RWD can inform the understanding of disease, help identify new therapeutic intervention points, and improve the efficiency of research and development (R&D), especially clinical trials. Pursuing precompetitive collaborations to define shared requirements for the use of RWD would equip service-providers with the specifications needed to implement cloud-based solutions for RWD acquisition, management and analysis. Only this approach would deliver cost-effective solutions to an industry-wide problem

Adenosyl Radical: Reagent and Catalyst in Enzyme Reactions

Adenosine is undoubtedly an ancient biological molecule that is a component of many enzyme cofactors: ATP, FADH, NAD(P)H, and coenzyme A, to name but a few, and, of course, of RNA. Here we present an overview of the role of adenosine in its most reactive form: as an organic radical formed either by homolytic cleavage of adenosylcobalamin (coenzyme B 12 , AdoCbl) or by single-electron reduction of S -adenosylmethionine (AdoMet) complexed to an iron–sulfur cluster. Although many of the enzymes we discuss are newly discovered, adenosine's role as a radical cofactor most likely arose very early in evolution, before the advent of photosynthesis and the production of molecular oxygen, which rapidly inactivates many radical enzymes. AdoCbl-dependent enzymes appear to be confined to a rather narrow repertoire of rearrangement reactions involving 1,2-hydrogen atom migrations; nevertheless, mechanistic insights gained from studying these enzymes have proved extremely valuable in understanding how enzymes generate and control highly reactive free radical intermediates. In contrast, there has been a recent explosion in the number of radical-AdoMet enzymes discovered that catalyze a remarkably wide range of chemically challenging reactions; here there is much still to learn about their mechanisms. Although all the radical-AdoMet enzymes so far characterized come from anaerobically growing microbes and are very oxygen sensitive, there is tantalizing evidence that some of these enzymes might be active in aerobic organisms including humans.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/69165/1/604_ftp.pd

Mise en place d'un organisation BPL dans un laboratoire d'analyses de résidus. Contraintes, avantages et inconvénients

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Quelques questions autour de la notion de référence

Professorat des collèges et lycéesLa référence apparaît dans les programmes comme un élément incontournable du cours d’arts plastiques. En effet, les textes officiels recommandent à l’enseignant de s’appuyer sur des " références artistiques ", mais ne précisent pas quelle doit être la nature de la référence, ni quel moment privilégier pour l’introduire, ou encore, de quelle façon l’analyser… Ce mémoire essaie d’apporter les réponses aux questions que se pose, sans doute, tout jeune enseignant : il tente de cerner les contours de cette notion de " référence "

Path computation algorithms in IP networks : reliable hot-potato routing & deployable multi-constrained tunnels

Les travaux présentés dans cette thèse se décomposent en deux parties centrées autour du routage. Nous nous intéressons d'abord aux calculs de chemins multicritères, notamment utiles pour router du trafic exigeant une latence faible. Le problème NP-Difficile étudié, appelé DCLC, devient radicalement plus complexe lorsque l'on considère les contraintes opérationnelles rajoutées par la technologie utilisée pour déployer ces chemins, Segment Routing. Nous proposons différents méthodes et algorithmes afin de résoudre DCLC dans un tel contexte opérationnel, et montrons l'efficacité de nos solutions via une évaluation sur des réseaux large-échelle. Nous nous concentrons ensuite sur les effets néfastes induits par les interactions inter-protocolaires. Les interactions entre BGP (le protocole de routage utilisé dans l'Internet) et l'IGP (utilisé au sein d'un réseau) provoquent un temps de convergence long lors de changements topologiques. Nous retravaillons ces interactions et proposons OPTIC, ramenant ce temps de convergence à une durée marginale. Nous montrons la faisabilité d'OPTIC via évaluation théorique basée sur des données réelles.The work presented in this thesis is divided into two parts centered around routing. First, we focus on multi-criteria path computations, which are particularly useful for routing traffic requiring low latency. The NP-hard problem studied, called DCLC, becomes radically more complex when we consider the operational constraints added by the technology used to deploy these paths, Segment Routing. We propose different methods and algorithms to solve DCLC in such an operational context, and show the efficiency of our solutions via an evaluation on large-scale networks. We then focus on the adverse effects induced by inter-protocol interactions. Interactions between BGP (the routing protocol used in the Internet) and the IGP (used within a network) cause long convergence times during topological changes. We rework these interactions and propose OPTIC, reducing this convergence time to a marginal duration. We show the feasibility of OPTIC via theoretical evaluation based on real data

Intégration et valorisation du livre électronique : quel impact pour la fonction documentaire ?

A travers l'exemple d'un Institut de recherche, ce mémoire pose la question de l'impact de l'intégration et de la valorisation du livre électronique sur la fonction documentaire. S'agit-il de valoriser un médium ou plus largement des services et des compétences ? La première partie présente la place qu'occupe le livre numérique dans le marché global de l'édition et dans celui de l'édition scientifique, analyse son usage puis le situe dans les débats des professionnels de l'information. La deuxième partie est consacrée aux concepts et outils de valorisation appliqués aux ebooks et autres produits numériques mais aussi aux missions des services de documentation. La dernière partie présente des pistes de réflexion auxquelles a conduit ce travail