Cold-seep benthic communities in the Japan subduction zones: Geological control of community development

A large number of Calyptogena-dominated benthic communities, apparently chemosynthetically-based, were discovered at methane-rich pore-water seeps in the Japan subduction zones (3850–6000 m depth). Photographic and video surveys from four submersible dives were analyzed to study the influence of faulting, topography and substratum on exploitation of cold seeps by megafauna. Pore-water seepage occurred in a variety of geological settings, including subduction-erosion and accretionary prism formation, always in association with major faults which likely facilitated upward migration of fluids from a deep high-pressure zone. Sediment cover and manganese crusts on the seafloor appeared to block pore-water discharge, except where interrupted by erosion, slumping or outcropping. Sediment or mudstone substrata may increase lateral diffusion of rising fluids, permitting more extensive biological exploitation than where fluids discharge directly from exposed rock. Cold seeps are ephemeral. Large long-lived “fields” of cold seeps may be important in the maintenance of regional populations of seep organisms and the transfer of cold-seep productivity to the surrounding deep-sea ecosystem

Effets de la collision "ride des Loyauté - arc des Nouvelles-Hébrides" sur la terminaison sud de l'ensemble "Nouvelle Calédonie - Loyauté"

Les données de bathymétrie multifaisceaux et de géophysique de la campagne ZoNéCo 1 révèlent, au niveau du prolongement sud des rides de Nouvelle-Calédonie et des Loyauté, la présence de trois directions structurales et de deux phases volcaniques majeures. La direction WSW-ENE se retrouve sur l'ensemble de la zone "ride de Norfolk-bassin et ride des Loyauté" sous la forme de décrochements sénestres. La direction NNW-SSE est caractérisée par un réseau de failles normales. La direction SSW-NNE est présente au Sud de 24°40'S le long de la ride de Norfolk et s'exprime, sur la ride des Loyauté, par des failles normales et des décrochements dextres localisés. La première phase volcanique, ayant généré les guyots qui forment le substratum des deux rides, est vraisemblablement d'âge Oligocène-Miocène inférieur. La seconde phase, qui s'exprime par des volcans non érodés, pourrait être postérieure à la surrection Miocène supérieur-Pliocène. Les décrochements sénestres WSW-ENE qui découpent la plaque australienne sont interprétés comme résultant de la collision active "Loyauté - Nouvelles-Hébrides", l'arc des Nouvelles-Hébrides se comportant comme un poinçon rigide. (Résumé d'auteur

Some Formal Solutions in Side-channel Cryptanalysis - An Introduction

We propose to revisit Side-channel Cryptanalysis from the point of view, for instance, of C. E. Shannon: The calculation of a posteriori probabilities is the generalized problem of cryptanalysis. So, our goal will be to provide analytic formulae for the marginal posterior probability mass functions for the targets of those attacks. Since we are concerned with the probabilities of single and perfectly determined cases, we need above all to place ourselves in a probabilistic system enjoying an epistemic “interpretation”. We select Probability as Logic, the most suitable system for our purpose. With this powerful and flexible system at hand, we first solve two independent problems for known, non-chosen messages: the determination of side-channel leakage times (generalized for high-order attacks) and the determination of the target, given those leakage times. The first problem belongs to Hypotheses Testing Theory and admits a formal solution in terms of Bayes Factors in the parametric framework. The calculation of those factors requires marginalizing over all possible values of the target, so that this new procedure has no equivalent in frequentist Statistics and we indicate how it could be proved to outperform previous procedures more and more, as the target space size increases. We present preliminary experimental results and give some clues on how to extend this solution to the nonparametric framework. The second problem is a classical Parameter Estimation problem with many hyperparameters. It also admits a unique maximum a posteriori solution under 0-1 loss function within Decision Theory. When it is not possible to solve both problems independently, we must solve them simultaneously in order to get general solutions for Side-channel Cryptanalysis on symmetric block ciphers, at least. Taking benefit of the duality between Hypotheses Testing and Parameter Estimation in our system of inference, we transform the determination of the generalized leakage times into a parameter estimation problem, in order to fall back into a global parameter estimation problem. Generally speaking, it appears that (marginal) side-channel parametric leakage models are in fact averages between attack and “non-attack” models and, more generally between many conditional models, so that likelihoods can not be frequency sampling distributions. Then, we give the marginal posterior probability mass function for the targets of the most general known-messages attacks: “correlation” attacks, template attacks, high-order attacks, multi-decision functions attacks, multi-attack models attacks and multi-“non-attack” models attacks. Essentially, it remains to explain how to assign joint prior and discrete direct probability distributions by logical inspection, to extent this approach to the nonparametric framework and other cryptographic primitives, to deal with analytic, symbolic, numerical and computational implementation issues and especially to derive formal adaptive chosen-messages attacks

Beyond the divide: Boundaries for patterning and stem cell regulation in plants

The initiation of plant lateral organs from the shoot apical meristem (SAM) is closely associated with the formation of specialized domains of restricted growth known as the boundaries. These zones are required in separating the meristem from the growing primordia or adjacent organs but play a much broader role in regulating stem cell activity and shoot patterning. Studies have revealed a network of genes and hormone pathways that establish and maintain boundaries between the SAM and leaves. Recruitment of these pathways is shown to underlie a variety of processes during the reproductive phase including axillary meristems production, flower patterning, fruit development, and organ abscission. This review summarizes the role of conserved gene modules in patterning boundaries throughout the life cycle

Jean Charcot Seabeam Survey along ODP Leg 112 Northern Transect

A marine geophysical survey that used Seabeam, multi- and single-channel seismic reflection, gravity, and magnetic profiling was conducted in two locations along the landward slope of the Peru Trench. This survey was conducted during the SeaPERC cruise of the Jean Charcot in July 1986 (Bourgois et al., 1986a; Bourgois et al., 1986b; Bourgois et al., 1987; Bourgois et al., in press). These areas were two possible drilling locations for ODP Leg 112, which was scheduled to begin in November 1986. The drilling transects center around latitudes of 5°30'S and 9°30'S, along multichannel seismic lines CDP-3 and CDP-2, respectively. The northern transect is located in the Paita Zone (Fig. 1, Box 2), and the southern transect is in the Chimbote Zone (Fig. 1, Box 6). During Leg 112, we drilled two sites (683 and 685) in the Chimbote area. This became the northern transect of Leg 112. Here, we report the Seabeam data acquired during the SeaPERC cruise. Drilling results from Sites 683 and 685, the CDP-2 multichannel seismic record, and the Seabeam data provide a threedimensional view of this region

Realignment-enhanced coherent anti-Stokes Raman scattering (CARS) and three-dimensional imaging in anisotropic fluids

We apply coherent anti-Stokes Raman Scattering (CARS) microscopy to characterize director structures in liquid crystals.Comment: 14 pages, 11 figure

Seabeam and seismic reflection imaging of the tectonic regime of the Andean continental margin off Peru (4°S to 10°S)

Suite à une campagne géophysique réalisée au large de la côte du Perou (croisière Seaperc du R/V "Jean Charcot", juillet 1986), les auteurs proposent une nouvelle interprétation des structures caractérisant la pente continentale de la région étudiée. D'autre part, ils considèrent que cette marge active est une marge active en extension ou bien une marge d'effondrement qui développe un complexe d'accrétion induit par les effondrements de la partie médiane de la pente