Profiling of Amatoxins and Phallotoxins in the Genus Lepiota by Liquid Chromatography Combined with UV Absorbance and Mass Spectrometry

Species in the mushroom genus Lepiota can cause fatal mushroom poisonings due to their content of amatoxins such as α-amanitin. Previous studies of the toxin composition of poisonous Lepiota species relied on analytical methods of low sensitivity or resolution. Using liquid chromatography coupled to UV absorbance and mass spectrometry, we analyzed the spectrum of peptide toxins present in six Italian species of Lepiota, including multiple samples of three of them collected in different locations. Field taxonomic identifications were confirmed by sequencing of the internal transcribed spacer (ITS) regions. For comparison, we also analyzed specimens of Amanita phalloides from Italy and California, a specimen of A. virosa from Italy, and a laboratory-grown sample of Galerina marginata. α-Amanitin, β-amanitin, amanin, and amaninamide were detected in all samples of L. brunneoincarnata, and α-amanitin and γ-amanitin were detected in all samples of L. josserandii. Phallotoxins were not detected in either species. No amatoxins or phallotoxins were detected in L. clypeolaria, L. cristata, L. echinacea, or L. magnispora. The Italian and California isolates of A. phalloides had similar profiles of amatoxins and phallotoxins, although the California isolate contained more β-amanitin relative to α-amanitin. Amaninamide was detected only in A. virosa

The dynamical control of subduction parameters on surface topography

he long-wavelength surface deflection of Earth's outermost rocky shell is mainly controlled by large-scale dynamic processes like isostasy or mantle flow. The largest topographic amplitudes are therefore observed at plate boundaries due to the presence of large thermal heterogeneities and strong tectonic forces. Distinct vertical surface deflections are particularly apparent at convergent plate boundaries mostly due to the convergence and asymmetric sinking of the plates. Having a mantle convection model with a free surface that is able to reproduce both realistic single-sided subduction and long-wavelength surface topography self-consistently, we are now able to better investigate this interaction. We separate the topographic signal into distinct features and quantify the individual topographic contribution of several controlling subduction parameters. Results are diagnosed by splitting the topographic signal into isostatic and residual components, and by considering various physical aspects like viscous dissipation during plate bending. Performing several systematic suites of experiments, we are then able to quantify the topographic impact of the buoyancy, rheology, and geometry of the subduction-zone system to each and every topographic feature at a subduction zone and to provide corresponding scaling laws. We identify slab dip and, slightly less importantly, slab buoyancy as the major agents controlling surface topography at subduction zones on Earth. Only the island-arc high and the back-arc depression extent are mainly controlled by plate strength. Overall, his modeling study sets the basis to better constrain deep-seated mantle structures and their physical properties via the observed surface topography on present-day Earth and back through time

Mind the Gap - A Closer Look at the Security of Block Ciphers against Differential Cryptanalysis

Resistance against differential cryptanalysis is an important design criteria for any modern block cipher and most designs rely on finding some upper bound on probability of single differential characteristics. However, already at EUROCRYPT'91, Lai et al. comprehended that differential cryptanalysis rather uses differentials instead of single characteristics. In this paper, we consider exactly the gap between these two approaches and investigate this gap in the context of recent lightweight cryptographic primitives. This shows that for many recent designs like Midori, Skinny or Sparx one has to be careful as bounds from counting the number of active S-boxes only give an inaccurate evaluation of the best differential distinguishers. For several designs we found new differential distinguishers and show how this gap evolves. We found an 8-round differential distinguisher for Skinny-64 with a probability of 2−56.932−56.93, while the best single characteristic only suggests a probability of 2−722−72. Our approach is integrated into publicly available tools and can easily be used when developing new cryptographic primitives. Moreover, as differential cryptanalysis is critically dependent on the distribution over the keys for the probability of differentials, we provide experiments for some of these new differentials found, in order to confirm that our estimates for the probability are correct. While for Skinny-64 the distribution over the keys follows a Poisson distribution, as one would expect, we noticed that Speck-64 follows a bimodal distribution, and the distribution of Midori-64 suggests a large class of weak keys

abstractXOR: A global constraint dedicated to differential cryptanalysis

International audienceConstraint Programming models have been recently proposed to solve cryptanalysis problems for symmetric block ciphers such as AES. These models are more efficient than dedicated approaches but their design is difficult: straightforward models do not scale well and it is necessary to add advanced constraints derived from cryptographic properties. We introduce a global constraint which simplifies the modelling step and improves efficiency. We study its complexity, introduce propagators and experimentally evaluate them on two cryptanalysis problems (single-key and related-key) for two block ciphers (AES and Midori)

Préparation et structure cristalline d'un chromate bichromate de fer Fe2 (CrO4)2 Cr2O7, 4H2O

The new compound Fe₂ (CrO₄)₂ Cr₂O₇, 4H₂O is synthetized at 50° C in the ternary system Fe₂O₃, CrO₃, H₂O. The formula of this new salt which occurs in two crystal forms : α monoclinic, space group P2/n, and β orthorhombic, space group Cmc2₁ or Cmcm, is established after the structural determination. The structure of the α form is determined with Patterson and electronic density functions. The intensity data are measured on an automatic CAD ₄ diffractometer. The structure consists of CrO₄⁻ and Cr₂O₇⁻ groups which connect [FeO₆] octahedron. Two oxygens of each octahedron belong to water molecules. These groups form undulating layers parallel to the (a, c) plane, linked solely by hydrogen bonds.L'étude du ternaire Fe₂O₃, CrO₃, H₂O à 50° C met en évidence un nouveau composé auquel la formule Fe₂ (CrO₄)₂ Cr₂O₇, 4H₂O n'a été attribuée définitivement qu'après la détermination de la structure. Ce chromate bichromate de fer existe sous deux variétés allotropiques α et ß qui cristallisent respectivement dans les systèmes monoclinique, groupe spatial P2/n, et orthorhombique, groupe Cmc2₁ ou Cmcm. La structure de α a été déterminée à l'aide de fonctions de Patterson et de densité électronique. Les intensités ont été recueillies par un diffractomètre automatique CAD ₄. Cette structure est caractérisée par la présence simultanée de groupements CrO₄⁻ et Cr₂O₇⁻ qui relient des octaèdres [FeO₆], dont deux oxygènes appartiennent à des molécules d'eau, formant ainsi des feuillets ondulés parallèles au plan (a, c). Les liaisons par pont hydrogène assurent la cohésion de la structure.Gérault Yves, Bonnin André. Préparation et structure cristalline d'un chromate bichromate de fer Fe2 (CrO4)2 Cr2O7, 4H2O. In: Bulletin de la Société française de Minéralogie et de Cristallographie, volume 99, 4, 1976. pp. 197-202

Les archives de l'administration centrale du Ministère de l'Équipement et du Logement

Couédelo Rose-Anne, Gérault Louis. Les archives de l'administration centrale du Ministère de l'Équipement et du Logement. In: La Gazette des archives, n°71, 1970. pp. 239-250

Revisiting AES Related-Key Differential Attacks with Constraint Programming

International audienceThe Advanced Encryption Standard (AES) is one of the most studied symmetric encryption schemes. During the last years, several attacks have been discovered in different adversarial models. In this paper, we focus on related-key differential attacks, where the adversary may introduce differences in plaintext pairs and also in keys. We show that Constraint Programming (CP) can be used to model these attacks, and that it allows us to efficiently find all optimal related-key differential characteristics for AES-128, AES-192 and AES-256. In particular, we improve the best related-key differential for the whole AES-256 and give the best related-key differential on 10 rounds of AES-192, which is the differential trail with the longest path. Those results allow us to improve existing related-key distinguishers, basic related-key attacks and q-multicollisions on AES-256

On the relative influence of heat and water transport on planetary dynamics

International audienceThe dynamics of a planet and its evolution are controlled to a large extent by its viscosity. In this study, we demonstrate that the dependence of mantle viscosity on temperature and water concentration introduces strong dynamic feedbacks. We derive a dimensionless parameter to quantitatively evaluate the relative strength of those feedbacks, and show that water and heat transport are equally important in controlling present-day dynamics for the Earth. A simple parameterized evolution model illustrates the strong feedbacks and behavior of the system and agrees well with our analytic results. The analysis identifies characteristic times for changes of viscosity, temperature, and water concentration and demonstrates, for time scales greater than a few hundred million years, that the system should either be degassing while warming or regassing while cooling. This yields a characteristic evolution in which, after an initial period of rapid adjustment, the mantle warms while degassing, and subsequently cools rapidly while regassing. As the planet continues to cool, the entire surface ocean may eventually return to the mantle. Our results suggest that a simple relationship may exist between the rate of change of water concentration and the rate of change of temperature in the mantle. This connection is extended by deriving an explicit equation for the Urey ratio that depends on both heat and water transport

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Il est aujourd'hui acquis que la mise en valeur et l'exploitation des ruines de l’abbaye Sainte-Marie d’Aulps est une réussite patrimoniale. Un long cheminement a cependant été nécessaire pour atteindre cet état d’accomplissement. Il a fallu l’acharnement du SIDET de la vallée d’Aulps, le soutien des services patrimoniaux de la DRAC (Service régional de l'archéologie, et Conservation régionale des monuments historiques), du CAUE et du Conseil Général de Haute-Savoie, désormais propriétaire de..