Approches géostrategique et économique de la menace : réponses américaines (Geostrategic and economic approaches of the threat : american answers )

En 2001, le Department of Defense (DoD) des Etats-Unis a décidé de développer un « système de systèmes », désigné sous le nom de Ballistic Missile Defense System (BMDS)1 destiné à protéger les États-Unis contre une attaque limitée de missiles balistiques provenant d’États incertains et la prolifération des armes de destruction massive. Nous explorerons une approche géostratégique et économique des nouvelles menaces et nous examinerons les réponses américaines qui sont fondées sur la réaffirmation de leur statut d’hyper puissance par la maîtrise technologique face à une absence de réponse européenne. 1 Le Système de Défense contre les Missiles Balistiques inclut la Défense Nationale Antimissile (NMD) pour protéger le territoire des États-Unis, et la Défense Antimissile de Théâtre (TMD) pour protéger les forces alliées ou amies déployées sur un théâtre d'opérations militaires. In 2001, the Department of Defense ( DoD) of the United States decided to develop a « system of systems », under the name of Ballistic Missile Defense System ( BMDS)1, intended to protect the United States against limited ballistic missile attacks coming from the rogue States and the proliferation of weapons of mass destruction.. We shall investigate a geo-strategic and economic approach of the new threats and we shall also examine the American answers which are based primarily on the reaffirmation of their status of hyper power by their technological supremacy and the absence of European answer. 1 Ballistic Missile Defense System includes National Missile Defense (NMD), to protect the United States homeland, and Theater Missile Defense (TMD), to protect deployed forces, allies, and friends elsewhere in a theatre of military operations.Géostratégie, défense, Etats-Unis, BMDS/Geostrategy, Defense, USA, BMDS

DNA methylation: a historical perspective

In 1925, 5-methylcytosine was first reported in bacteria. However, its biological importance was not intuitive for several decades. After this initial lag, the ubiquitous presence of this methylated base emerged across all domains of life and revealed a range of essential biological functions. Today, we are armed with the knowledge of the key factors that establish, maintain, and remove DNA methylation and have access to a staggering and rapidly growing number of base-resolution methylation maps. Despite this, several fundamental details about the precise role and interpretation of DNA methylation patterns remain under investigation. Here, we review the field of DNA methylation from its beginning to present day, with an emphasis on findings in mammalian systems, and point the reader to select experiments that form the foundation of this field

Clustering with shallow trees

We propose a new method for hierarchical clustering based on the optimisation of a cost function over trees of limited depth, and we derive a message--passing method that allows to solve it efficiently. The method and algorithm can be interpreted as a natural interpolation between two well-known approaches, namely single linkage and the recently presented Affinity Propagation. We analyze with this general scheme three biological/medical structured datasets (human population based on genetic information, proteins based on sequences and verbal autopsies) and show that the interpolation technique provides new insight.Comment: 11 pages, 7 figure

Protention and retention in biological systems

This paper proposes an abstract mathematical frame for describing some features of cognitive and biological time. We focus here on the so called "extended present" as a result of protentional and retentional activities (memory and anticipation). Memory, as retention, is treated in some physical theories (relaxation phenomena, which will inspire our approach), while protention (or anticipation) seems outside the scope of physics. We then suggest a simple functional representation of biological protention. This allows us to introduce the abstract notion of "biological inertia".Comment: This paper was made possible only as part of an extended collaboration with Francis Bailly (see references), a dear friend and "ma\^itre \'a penser", who contributed to the key ideas. Francis passed away in february 2008: we continue here our inspiring discussions and joint wor

The Emergence of Interactive Behaviour: A Model of Rational Menu Search

One reason that human interaction with technology is difficult to understand is because the way in which people perform interactive tasks is highly adaptive. One such interactive task is menu search. In the current article we test the hypothesis that menu search is rationally adapted to (1) the ecological structure of interaction, (2) cognitive and perceptual limits, and (3) the goal to maximise the trade-off between speed and accuracy. Unlike in previous models, no assumptions are made about the strategies available to or adopted by users, rather the menu search problem is specified as a reinforcement learning problem and behaviour emerges by finding the optimal policy. The model is tested against existing empirical findings concerning the effect of menu organisation and menu length. The model predicts the effect of these variables on task completion time and eye movements. The discussion considers the pros and cons of the modelling approach relative to other well-known modelling approaches

Cosmological evolution of scalar fields and gravitino dark matter in gauge mediation at low reheating temperatures

We consider the dynamics of the supersymmetry-breaking scalar field and the production of dark matter gravitinos via its decay in a gauge-mediated supersymmetry breaking model with metastable vacuum. We find that the scalar field amplitude and gravitino density are extremely sensitive to the parameters of the hidden sector. For the case of an O'Raifeartaigh sector, we show that the observed dark matter density can be explained by gravitinos even for low reheating temperatures T_{R} < 10 GeV. Such low reheating temperatures may be implied by detection of the NLSP at the LHC if its thermal freeze-out density is in conflict with BBN.Comment: 11 pages RevTex. Extended discussion and minor corrections, conclusions unaltered. Version to be published in JCA

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