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Quelle sagesse collective pour les nouvelles technologies par les normes juridiques ?
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A new correlation model for ultrasonic attenuation in polycrystals with broad grain size distributions
No full textInternational audienceUltrasonic characterization of polycrystalline materials is traditionally based on a single-exponential two-point correlation function (TPCF). However, industrial metallic polycrystals often exhibit a wide grain size distribution, for which the classical analytical scattering-induced attenuation frameworks fail to reproduce the experimental measurements. In this paper, we introduce a new closed-form TPCF that embeds the full volumetric grain size distribution through an analytic convolution of spherical grain statistics. The resulting expression naturally reduces to the classical spherical TPCF when the distribution width tends to zero. Coupling this TPCF with Weaver's framework for elastic wave attenuation produces frequency-dependent attenuation formulas that depend on the first two moments of the grain size distribution.To evaluate the robustness of the proposed model, we generated synthetic aluminum microstructures that span a wide range of coefficients of variation of grain sizes. TPCFs measured from Laguerre-Voronoi tessellation-based microstructures closely match our predictions across a wide range of coefficients of variations (CVs) from moderate to large, whereas other models</div
A Hybrid Message-level Modeling Approach for Fast Yet Accurate Simulation of Multiprocessor Shared Bus Effects on Data Flow Applications Execution
No full textInternational audienceFast yet accurate performance and timing prediction of complex parallel data flow applications on multiprocessor systems remains a challenging discipline. The main reason is that the applications contain numerous degrees of parallelism (task, pipeline, data) but they necessitate sharing resources, such as communication buses and memories, within execution platforms. Executing such applications on resource-limited platforms leads to timing interferences that are difficult to accurately express in pure analytical approaches or to excessive simulation duration for cycle-accurate models. In this work, we propose a message-level communication model for fast yet accurate performance prediction for data flow applications executed on MPSoCs with shared memories and buses. This approach combines a high level executable model of the communication infrastructure with a formal description of the synchronization instants related to low-level communication mechanisms. This combination significantly reduces the number of simulation events while still accurately predicting the effects of contention at shared resources. We evaluated our work against measurements from a real prototype and cycle-accurate performance prediction models on two case-studies from the computer vision domain. We illustrated how the computational complexity of our approach can be adapted to deliver high simulation efficiency. In our experiment, we achieved an average accuracy of 99% in latency prediction compared to real implementation for the different use-cases and mappings we considered. In the experiments where the approach is used with limited computational complexity, simulation speed-ups of an order of magnitude of 104 compared to cycle-accurate models are achieved, while maintaining a fully acceptable accuracy (more than 98%). Good suitability for fast and accurate exploration of the design space is demonstrated by the proposed models
Les inégalités territoriales d'éducation. Approches sociologiques et géographiques
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Linear Effects, Exceptions, and Resource Safety: A Curry-Howard Correspondence for Destructors
No full textDraft pre-printInternational audienceWe analyse the problem of combining linearity, effects, and exceptions, in abstract models of programming languages, as the issue of providing some kind of strength for a monad in a linear setting. We consider in particular for the \emph{allocation monad}, which we introduce to model and study resource-safety properties. We apply these results to a series of two linear effectful calculi for which we establish their resource-safety properties. The first calculus is a linear call-by-push-value language with two allocation effects new and delete. The resource-safety properties follow from the linear (and even ordered) character of the typing rules. We then explain how to integrate exceptions on top of linearity and effects by adjoining default destruction actions to types, as inspired by C++/Rust destructors. We see destructors as objects in the slice category over . This construction gives rise to a second calculus, an \emph{affine} ordered call-by-push-value language with exceptions and destructors, in which the weakening rule performs a side-effect. As in C++/Rust, a ``move'' operation is necessary to allow random-order release of resources, as opposed to last-in-first-out order. Moving resources is modelled as an exchange rule that performs a side-effect
The Greeks among the natives: Culture, ritual, and craftmanship in non-colonial spaces of the Southern Italy Iron Age
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Temperate phage evolve to integrate host stress and quorum signals in lysis-lysogeny decisions
No full textInternational audienceTemperate phage can transmit both horizontally (lytic cycle) and vertically (lysogenic cycle). Many temperate phage have the ability to modify their lysis/lysogeny decisions based on various environmental cues. For instance, many prophage are known to reactivate when SOS stress responses of their host are triggered. Temperate phage infecting Bacilli can also use peptide signals (“arbitrium”) to control their lysis/lysogeny decisions. However, information from the arbitrium and SOS systems can be potentially conflicting, and it is unclear how phage integrate information carried by these two different signals when making lysis–lysogeny decisions. Here, we use evolutionary epidemiology theory to explore how phage could evolve to use both systems to modulate lysis/lysogeny decisions in a fluctuating environment. Our model predicts that it can be adaptive for phage to respond to both host SOS systems and arbitrium signaling, as they provide complementary information on the quality of the infected host and the availability of alternative hosts. Using the phage phi3T and its host Bacillus subtilis , we show that during lytic infection and as prophage, lysis–lysogeny decisions rely on the integration of information on host condition and arbitrium signal concentrations. For example, free-phage are more likely to lysogenise a stressed host, and prophage are less likely to abandon a stressed host, when high arbitrium concentrations suggest susceptible hosts are unavailable. These experimental results are consistent with our theoretical predictions and demonstrate that phage can evolve plastic life-history strategies to adjust their infection dynamics to account for both the within-host environment (host quality) and the external environment that exists outside of their host (availability of susceptible hosts in the population). More generally, our work yields a new theoretical framework to study the evolution of viral plasticity under the influence of multiple environmental cues
HGG-40. EXCEPTIONAL SYNCHRONOUS OCCURENCE OF A BRAF V600E MUTANT GLIOBLASTOMA AND A H3.3K27M MUTANT DIFFUSE INTRINSIC PONTINE GLIOMA: A CASE REPORT
No full textInternational audienceWe report herein the case of a 17-year-old female who presented with intracranial hypertension and diplopia. Magnetic resonance imaging showed a large left cystic and solid temporoparietal lesion, associated with an infiltrating lesion of the brainstem, hypointense in T1 and hyperintense in FLAIR sequences, without enhancement after injection of gadolinium. Complete resection of the parietal mass and biopsy of the brainstem lesion were performed. Histopathological analysis of the parietal mass showed glioblastoma (WHO grade IV) with no IDH1/2 or H3.3/H3.1 gene mutation detected by Sanger sequencing. Immunohistochemistry found the expression of the proteins of mismatch repair system. Whole exome and RNA sequencing identified a BRAF-V600E mutation. The brainstem lesion was a diffuse midline glioma, H3K27M-mutant (grade IV) according to the 2016 WHO classification. Pan-genomic SNP arrays of the 2 tumors showed distinct genetic alterations. The parietal glioblastoma displayed complex genomic alterations whereas the brainstem glioma harbored chromosome 7q gain, chromosome 9p and 10 losses, and RB, TP53 and CDKN2A homozygous deletions. The patient was treated by concomitant radiochemotherapy (according to Stupp protocol). After 12 cycles of temozolomide, there was complete remission persistant in the parietal lobe. The brainstem tumor was stable but progressed after 3 months of temozolomide discontinuation. Treatment with mTOR inhibitors was initiated. At 21-month follow-up, the patient remains with few symptoms. No predisposition syndrome was identified in the patient or her family. Concurrent glioblastomas with distinct driver gene mutations are exceptional