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The chiral self‐assembly of trispentahelicene propellers on a gold surface has been investigated in ultrahigh vacuum by means of scanning tunneling microscopy and time‐of‐flight secondary ion mass spectrometry. The trispentahelicene propellers aggregate into mirror domains with an enantiomeric ratio of 2 : 1. Thermally induced cyclodehydrogenation leads to planarization into nanographenes, which self‐assemble into closed‐packed layers with two different azimuths. Further treatment induces in part dimerization and trimerization by intermolecular cyclodehydrogenation., From helical to planar: Molecular propellers built up by three pentahelicene subunits self‐assemble on a gold surface into enantiomerically unbalanced two‐dimensional crystal domains. Upon thermal treatment of the close‐packed monolayer, intramolecular cyclodehydrogenation into planar nanographenes occurs. Further thermal treatment leads in part to fusion into larger graphene flakes of up to four nanographene units by intermolecular cyclodehydrogenation.

2D NMR is an immensely powerful structural tool but it is time‐consuming. Targeting individual chemical groups by selective excitation in a 1D experiment can give the information required far more quickly. A major problem, however, is that proton NMR spectra are often extensively overlapped, so that in practice only a minority of sites can be selectively excited. Here we overcome that problem using a fast, single‐scan method that allows selective excitation of the signals of a single proton multiplet even where it is severely overlapped by other multiplets. The advantages of the method are illustrated in a selective 1D NOESY experiment, the most efficient way to determine relative configuration unambiguously by NMR. The new approach presented here has the potential to broaden significantly the applicability of selective excitation and unlock its real potential for many other experiments., Selective excitation of overlapped multiplets in a single scan broadens the applicability of 1D selective NMR experiments.

The orchestration of ever larger conformational changes is made possible by the development of increasingly complex foldamers. Aromatic sheets, a rare motif in synthetic foldamer structures, have been designed so as to form discrete stacks of intercalated aromatic strands through the self‐assembly of two identical subunits. Ion‐mobility ESI‐MS confirms the formation of compact dimers. X‐ray crystallography reveals the existence of two distinct conformational dimeric states that require large changes to interconvert. Molecular dynamics simulation validates the stability of the two conformations and the possibility of their interconversion., Unexpected conformational changes involving a global concerted rearrangement of the structure have been evidenced in large multistranded aromatic sheets. Increasing foldamer size thus gives access to new and defined conformational trajectories.

Light‐induced transitions between the trans and cis isomer of triazatriangulenium‐based azobenzene derivatives on Au(111) surfaces were observed directly by scanning tunneling microscopy, allowing atomic‐scale studies of the photoisomerization kinetics. Although the azobenzene units in these adlayers are free‐standing and spaced at uniform distances of 1.26 nm, their photoswitching depends on the isomeric state of the surrounding molecules and, specifically, is accelerated by neighboring cis isomers. These collective effects are supported by ab initio calculations indicating that the electronic excitation preferably localizes on the n–π* state of trans isomers with neighboring cis azobenzenes., Photoswitching in a well‐ordered self‐assembled monolayer of freestanding azobenzene derivatives was studied on the molecular scale with in situ scanning tunneling microscopy, infrared absorption spectroscopy, and ab initio calculations, revealing cooperative effects. Although the intermolecular distances prevent direct contact, trans–cis photoisomerization is enhanced by cis neighbors because the light‐induced excitation is localized.

A new family of five‐coordinate lanthanide single‐molecule magnets (Ln SMMs) [Dy(Mes*O)2(THF)2X] (Mes*=2,4,6‐tri‐tert‐butylphenyl; X=Cl, 1; Br, 2; I, 3) is reported with energy barriers to magnetic reversal >1200 K. The five‐coordinate DyIII ions have distorted square pyramidal geometries, with halide anions on the apex, and two Mes*O ligands mutually trans‐ to each other, and the two THF molecules forming the second trans‐ pair. These geometrical features lead to a large magnetic anisotropy in these complexes along the trans‐Mes*O direction. QTM and Raman relaxation times are enhanced by varying the apex halide from Cl to Br to I, or by dilution in a diamagnetic yttrium analogue., Halide influence: A new family of five‐coordinate lanthanide‐based single‐molecule magnets, [Dy(Mes*O)2(THF)2X] (Mes*=2,4,6‐tri‐tert‐butylphenyl), (X=Cl, Br, I) is reported. While the influence of the different halides on the quantum tunnelling of magnetization and Raman processes is clearly established, the Orbach relaxation is independent of the halide substitution.

The structurally unique “fleximer” nucleosides were originally designed to investigate how flexibility in a nucleobase could potentially affect receptor–ligand recognition and function. Recently they have been shown to have low‐to‐sub‐micromolar levels of activity against a number of viruses, including coronaviruses, filoviruses, and flaviviruses. However, the synthesis of distal fleximers in particular has thus far been quite tedious and low yielding. As a potential solution to this issue, a series of proximal fleximer bases (flex‐bases) has been successfully coupled to both ribose and 2′‐deoxyribose sugars by using the N‐deoxyribosyltransferase II of Lactobacillus leichmannii (LlNDT) and Escherichia coli purine nucleoside phosphorylase (PNP). To explore the range of this facile approach, transglycosylation experiments on a thieno‐expanded tricyclic heterocyclic base, as well as several distal and proximal flex‐bases were performed to determine whether the corresponding fleximer nucleosides could be obtained in this fashion, thus potentially significantly shortening the route to these biologically significant compounds. The results of those studies are reported herein., A thieno‐expanded tricyclic base and several distal and proximal flex‐bases have been converted into their corresponding fleximer nucleosides by enzymatic transglycosylation reactions catalyzed by N‐deoxyribosyltransferase from L. leichmannii (LlNDT) or E. coli purine nucleoside phosphorylase (PNP).

It is well known that symmetry plays a key role in chemical reactivity. Here we explore its role in vibrational strong coupling (VSC) for a charge‐transfer (CT) complexation reaction. By studying the trimethylated‐benzene–I2 CT complex, we find that VSC induces large changes in the equilibrium constant KDA of the CT complex, reflecting modifications in the ΔG° value of the reaction. Furthermore, by tuning the microfluidic cavity modes to the different IR vibrations of the trimethylated benzene, ΔG° either increases or decreases depending only on the symmetry of the normal mode that is coupled. This result reveals the critical role of symmetry in VSC and, in turn, provides an explanation for why the magnitude of chemical changes induced by VSC are much greater than the Rabi splitting, that is, the energy perturbation caused by VSC. These findings further confirm that VSC is powerful and versatile tool for the molecular sciences., We built this CT: By studying the mesitylene–I2 charge transfer (CT) complex, it is shown that vibrational strong coupling induces large changes in the equilibrium constant KDA of the CT complex, which can be either enhanced or suppressed depending only on the symmetry of the vibration coupled to the vacuum electromagnetic field.

Accurate quantification of the copy numbers of noncoding RNA has recently emerged as an urgent problem, with impact on fields such as RNA modification research, tissue differentiation, and others. Herein, we present a hybridization‐based approach that uses microscale thermophoresis (MST) as a very fast and highly precise readout to quantify, for example, single tRNA species with a turnaround time of about one hour. We developed MST to quantify the effect of tRNA toxins and of heat stress and RNA modification on single tRNA species. A comparative analysis also revealed significant differences to RNA‐Seq‐based quantification approaches, strongly suggesting a bias due to tRNA modifications in the latter. Further applications include the quantification of rRNA as well as of polyA levels in cellular RNA.

International audience; A general approach for the efficient hydrogen-isotope exchange of nucleobase derivatives is described. Catalyzed by ruthenium nanoparticles, using mild reaction conditions, and involving either D2 or T2 as isotopic sources, this reaction possesses a wide substrate scope and a high solvent tolerability. This novel method facilitates the access to essential diagnostic tools in drug discovery and development: tritiated pharmaceuticals with high specific activities and deuterated oligonucleotides suitable for use as internal standards during LC-MS quantification.

Here, we report the catalytic effect of vibrational strong coupling (VSC) on the solvolysis of para‐nitrophenyl acetate (PNPA), which increases the reaction rate by an order of magnitude. This is observed when the microfluidic Fabry–Perot cavity in which the VSC is generated is tuned to the C=O vibrational stretching mode of both the reactant and solvent molecules. Thermodynamic experiments confirm the catalytic nature of VSC in the system. The change in the reaction rate follows an exponential relation with respect to the coupling strength of the solvent, indicating a cooperative effect between the solvent molecules and the reactant. Furthermore, the study of the solvent kinetic isotope effect clearly shows that the vibrational overlap of the C=O vibrational bands of the reactant and the strongly coupled solvent molecules is critical for the catalysis in this reaction. The combination of cooperative effects and cavity catalysis confirms the potential of VSC as a new frontier in chemistry.

bibtex: ISI:000399384700030 bibtex\location:'POSTFACH 101161, 69451 WEINHEIM, GERMANY',publisher:'WILEY-V C H VERLAG GMBH',type:'Article',affiliation:'Walter, O (Reprint Author), European Commiss, Joint Res Ctr, Directorate Nucl Safety & Secur G, POB 2340, D-76125 Karlsruhe, Germany. Vogt, J; Edelmann, FT (Reprint Author), Otto von Guericke Univ, Inst Chem, Univ Pl 2, D-39106 Magdeburg, Germany. Maron, L (Reprint Author), Univ Toulouse, INSA, CNRS, Lab Phys & Chim Nanoobjets LPCNO,UMR5215, 135 Ave Rangueil, F-31077 Toulouse 4, France. Apostolidis, Christos; Walter, Olaf, European Commiss, Joint Res Ctr, Directorate Nucl Safety & Secur G, POB 2340, D-76125 Karlsruhe, Germany. Vogt, Jochen; Liebing, Phil; Edelmann, Frank T., Otto von Guericke Univ, Inst Chem, Univ Pl 2, D-39106 Magdeburg, Germany. Maron, Laurent, Univ Toulouse, INSA, CNRS, Lab Phys & Chim Nanoobjets LPCNO,UMR5215, 135 Ave Rangueil, F-31077 Toulouse 4, France.','author-email':'olaf.walter@ec.europa.eu jochen.vogt@ovgu.de laurent.maron@irsamc.ups-tlse.fr frank.edelmann@ovgu.de',da:'2018-12-05','doc-delivery-number':'ES2UZ',eissn:'1521-3773','funding-acknowledgement':'Otto-von-Guericke-Universitat Magdeburg','funding-text':'We thank the Otto-von-Guericke-Universitat Magdeburg for general financial support.','journal-iso':'Angew. Chem.-Int. Edit.','keywords-plus':'TRIS(ETA-5-CYCLOPENTADIENYL) ACTINIDE COMPLEXES; FOCK PERTURBATION-THEORY; BUILDING-BLOCK APPROACH; F-ORBITAL COVALENCY; SANDWICH COMPLEXES; ELECTRONIC-STRUCTURE; CRYSTAL-STRUCTURE; CYCLOOCTATETRAENYL COMPLEXES; TH-PU; ACTINOCENES','number-of-cited-references':'69',oa:'Other Gold, Green Published','orcid-numbers':'Edelmann, Frank T./0000-0001-5209-0018 walter, olaf/0000-0002-2679-1715 Liebing, Phil/0000-0002-4660-1691','research-areas':'Chemistry','times-cited':'8','unique-id':'ISI:000399384700030','usage-count-last-180-days':'2','usage-count-since-2013':'23','web-of-science-categories':'Chemistry, Multidisciplinary'\; International audience; The blood-red plutonocene complex Pu(1,3-COT `')(1,4-COT `') (4; COT `' = eta(8)-bis(trimethylsilyl) cyclooctatetraenyl) has been synthesized by oxidation of the anionic sandwich complex Li[Pu(1,4-COT `')(2)] (3) with anhydrous cobalt(II) chloride. The first crystal structure determination of an organoplutonium(IV) complex revealed an asymmetric sandwich structure for 4 where one COT `' ring is 1,3-substituted while the other retains the original 1,4-substitution pattern. The electronic structure of 4 has been elucidated by a computational study, revealing a probable cause for the unexpected silyl group migration.

International audience; The magnetic actuation of deposited drops has mainly relied on volume forces exerted on the liquid to be transported, which is poorly efficient with conventional diamagnetic liquids such as water and oil, unless magneto-sensitive particles are added. Herein, we describe a new and additive-free way to magnetically control the motion of discrete liquid entities. Our strategy consists of using a paramagnetic liquid as a deformable substrate to direct, using a magnet, the motion of various floating liquid entities, ranging from naked drops to liquid marbles. A broad variety of liquids, including diamagnetic (water, oil) and nonmagnetic ones, can be efficiently transported using the moderate magnetic field (ca. 50 mT) produced by a small permanent magnet. Complex trajectories can be achieved in a reliable manner and multi-plexing potential is demonstrated through on-demand drop fusion. Our paramagnetofluidic method advantageously works without any complex equipment or electric power, in phase with the necessary development of robust and low-cost analytical and diagnostic fluidic devices.

International audience; Drug delivery across the blood-brain barrier (BBB) is a formidable challenge for therapies targeting the central nervous system. Although BBB shuttle peptides enhance transport into the brain non-invasively, their application is partly limited by lability to proteases. The present study proposes the use of cyclic peptides derived from venoms as an affordable way to circumvent this drawback. Apamin, a neurotoxin from bee venom, was minimized by reducing its complexity, toxicity, and immunogenicity, while preserving brain targeting, active transport, and protease resistance. Among the analogues designed, the monocyclic lactam-bridged peptidomimetic MiniAp-4 was the most permeable. This molecule is capable of translocating proteins and nanoparticles in a human-cell-based BBB model. Furthermore, MiniAp-4 can efficiently deliver a cargo across the BBB into the brain parenchyma of mice.

This paper explores innovative low-cost technologies, widely used outside of Air Traffic Management (ATM), for use in airport surface surveillance. These technologies consist of a 5G-signal-based surveillance solution and a millimeter wave (mmWave) radar augmented with artificial intelligence (AI). The 5G solution is based on the combination of 3D Vector Antenna, innovative signal processing techniques, and hybridization techniques based on time-of-arrival and angle-ofarrival estimates with uplink and downlink 5G signals, as well as Machine Learning (ML)-based Line of Sight (LOS) detection algorithms. The mmWave solution is based on mmWave radar for non-cooperative target's positioning and sensing, combined with deep learning for objects classification. Standalone 5G positioning accuracy reaches m-level accuracy in LOS scenarios and it is better with downlink reference signals than with uplink ones, while it deteriorates quite drastically in NLOS scenarios. LOS detection accuracies above 84% average accuracy can be achieved with ML. The mmWave radar is tested in different scenarios (short, medium and long range) and it provides cost-effective surface surveillance up to few hundred meters (depending on the object radar cross section RCS) with ±60°field of view. The work is being conducted within the H2020 European-funded project NewSense and it delves into the 5G, Vector Antennas, mmWave, and ML/AI capabilities for future ATM solutions.

Descriptions and analyses in both media studies and communication studies correspond to a broad spectrum of terms, descriptive modalities, and ways of thematization. These terminologies and perspectives are partly overlapping but also distinct as regards histories and preferences in various academic contexts. Some expressions also serve as guiding metaphors, generic terms or catchwords with programmatic or paradigmatic claims. Medialization and mediatization are among these expressions that have achieved a high degree of popularity especially in German scholarly discourse. In this paper, we first examine some aspects of the politics of concepts of corresponding discourses in German media and communication studies. In contrast to synonymous or all-inclusive uses of the terms, we argue for a conceptual differentiation and constructive coexistence that can prove fruitful for both theoretical and empirical research.

Disparate biases associated with datasets and trained classifiers in hateful and abusive content identification tasks have raised many concerns recently. Although the problem of biased datasets on abusive language detection has been addressed more frequently, biases arising from trained classifiers have not yet been a matter of concern. Here, we first introduce a transfer learning approach for hate speech detection based on an existing pre-trained language model called BERT and evaluate the proposed model on two publicly available datasets annotated for racism, sexism, hate or offensive content on Twitter. Next, we introduce a bias alleviation mechanism in hate speech detection task to mitigate the effect of bias in training set during the fine-tuning of our pre-trained BERT-based model. Toward that end, we use an existing regularization method to reweight input samples, thereby decreasing the effects of high correlated training set' s n-grams with class labels, and then fine-tune our pre-trained BERT-based model with the new re-weighted samples. To evaluate our bias alleviation mechanism, we employ a cross-domain approach in which we use the trained classifiers on the aforementioned datasets to predict the labels of two new datasets from Twitter, AAE-aligned and White-aligned groups, which indicate tweets written in African-American English (AAE) and Standard American English (SAE) respectively. The results show the existence of systematic racial bias in trained classifiers as they tend to assign tweets written in AAE from AAE-aligned group to negative classes such as racism, sexism, hate, and offensive more often than tweets written in SAE from White-aligned. However, the racial bias in our classifiers reduces significantly after our bias alleviation mechanism is incorporated. This work could institute the first step towards debiasing hate speech and abusive language detection systems., Comment: This paper has been accepted in the PLOS ONE journal in August 2020

International audience; Task-based runtimes have emerged in the HPC world to take benefit from the computation power of heterogeneous supercomputers and to achieve scalability. One of the main bottlenecks for scalability is the communication layer. Some task-based algorithms need to send the same data to multiple nodes. To optimize this communication pattern , libraries propose dedicated routines, such as MPI Bcast. However, MPI Bcast requirements do not fit well with the constraints of task-based runtime systems: it must be performed simultaneously by all involved nodes, and these must know each other, which is not possible when each node runs a task scheduler not synchronized with others. In this paper, we propose a new approach, called dynamic broadcasts to overcome these constraints. The broadcast communication pattern required by the task-based algorithm is detected automatically, then the broadcasting algorithm relies on active messages and source routing, so that participating nodes do not need to know each other and do not need to synchronize. Receiver receives data the same way as it receives point-to-point communication, without having to know it arrives through a broadcast. We have implemented the algorithm in the StarPU runtime system using the NewMadeleine communication library. We performed benchmarks using the Cholesky factorization that is known to use broadcasts and observed up to 30% improvement of its total execution time.

International audience; Huge interest in controlling and manipulating electromagnetic waves is recently and strongly evolving, mainly due to the growing demand of reliable technologies in several application fields, such as communications, healthcare, military and safety. Despite the plethora of technologies existing nowadays, limitations are still present, such as limited speed, low response control, narrow band-width, and large dimensions of electronic devices. In this scenario, new engineered materials with unprecedented electromagnetic properties (i.e., MetaSurfaces) can represent a very suitable technology solution. In this paper, a MetaSurface structure is modelled, designed, manufactured and experimentally tested, to be used in several applications. Specifically, results are presented for (i) advanced medical diagnostics, (ii) enhance communication signals along curvilinear paths (i.e., bend optical fibers) and (iii) cloaking applications. Experimental results reveal that the MetaSurface can fully manipulate and process electromagnetic waves at will. The proposed structure appears to be highly versatile and scalable, with great potential to be used for many other practical applications.

Biological systems can share and collectively process information to yield emergent effects, despite inherent noise in communication. While man-made systems often employ intricate structural solutions to overcome noise, the structure of many biological systems is more amorphous. It is not well understood how communication noise may affect the computational repertoire of such groups. To approach this question we consider the basic collective task of rumor spreading, in which information from few knowledgeable sources must reliably flow into the rest of the population. We study the effect of communication noise on the ability of groups that lack stable structures to efficiently solve this task. We present an impossibility result which strongly restricts reliable rumor spreading in such groups. Namely, we prove that, in the presence of even moderate levels of noise that affect all facets of the communication, no scheme can significantly outperform the trivial one in which agents have to wait until directly interacting with the sources—a process which requires linear time in the population size. Our results imply that in order to achieve efficient rumor spread a system must exhibit either some degree of structural stability or, alternatively, some facet of the communication which is immune to noise. We then corroborate this claim by providing new analyses of experimental data regarding recruitment in Cataglyphis niger desert ants. Finally, in light of our theoretical results, we discuss strategies to overcome noise in other biological systems., Author summary Biological systems must function despite inherent noise in their communication. Systems that enjoy structural stability, such as biological neural networks, could potentially overcome noise using simple redundancy-based procedures. However, when individuals have little control over who they interact with, it is unclear what conditions would prevent runaway error accumulation. This paper takes a general stance to investigate this problem, concentrating on the basic information-dissemination task of rumor spreading. Drawing on a theoretical model, we prove that fast rumor spreading can only be achieved if some part of the communication setting is either stable or reliable. We then provide empirical support for this claim by conducting new analyses of data from experiments on recruitment in desert ants.

International audience; A common approach in HPC applications is to use MPI and OpenMP programming models to express the parallelism. Refined solutions are using asynchronous communications to take advantage from overlapping. In this paper we propose an early implementation of the ML-FMM algorithm using GASPI asynchronous one-sided communications to demonstrate how PGAS ad task based programming can impact the code performance. Early results, on 32 nodes, show a 49% improvement on communications over the optimized MPI+OpenMP version.

A new generation of UAVs is coming that will help improve the situational awareness and assessment necessary to ensure quality data collection, especially in difficult conditions like natural disasters. Operators should be relieved from time-consuming data collection tasks as much as possible and at the same time, UAVs should assist data collection operations through a more insightful and automated guidance thanks to advanced sensing capabilities. In order to achieve this vision, two challenges must be addressed though. The first one is to achieve a sufficient autonomy, both in terms of navigation and of interpretation of the data sensed. The second one relates to the reliability of the UAV with respect to accidental (safety) or even malicious (security) risks. This however requires the design and development of new embedded architectures for drones to be more autonomous, while mitigating the harm they may potentially cause. We claim that the increased complexity and flexibility of such platforms requires resorting to modelling, simulation, or formal verification techniques in order to validate such critical aspects of the platform. This paper first discusses the potential and challenges faced by autonomous UAVs for data acquisition. The design of a flexible and adaptable embedded UAV architecture is then addressed. Finally, the need for validating the properties of the platform is discussed. Our approach is sketched and illustrated with the example of a lightweight drone performing 3D reconstructions out of the combination of 2D image acquisition and a specific motion control.

This paper addresses the task of community detection and proposes a local approach based on a distributed list building, where each vertex broadcasts basic information that only depends on its degree and that of its neighbours. A decentralised external process then unveils the community structure. The relevance of the proposed method is experimentally shown on both artificial and real data., 2015 IEEE/ACM International Conference on Advances in Social Networks Analysis and Mining, Aug 2015, Paris, France. Proceedings of the 2015 IEEE/ACM International Conference on Advances in Social Networks Analysis and Mining

Purpose – The purpose of this paper is to examine the use of a positive country image (CI) by companies. First, it examines how organisations embed dimensions of a positive country image into their external marketing communications. Second, it examines the alignment between the countries’ image dimensions and those of the company and how company values and actions could act to either use, abuse and detract from an established CI. Design/methodology/approach – A two-part methodology was adopted. Two countries with strong positive CIs were chosen for comparison purposes. Content analysis of web sites, together with interviews with company representatives, were undertaken. Findings – The use of the CI/country-of-origin framework is extended from an extrinsic “made in” cue for consumers, to being part of the value offering of a particular product or service from an organisational perspective is extended. Evidence is structured into a framework of companies which use and/or contribute to the CI. Research limitations/implications – The two chosen countries both have positive CIs: future research should examine this relationship in countries with different images. The sample size is relatively small and future research should determine the generalisability of the proposed typology. Practical implications – Generating, communicating and maintaining a CI requires co-ordinated efforts from policy makers but needs to be built on solid foundations of reality: companies using CIs should be cognisant of the alignment between their actions, messages and the CI. Originality/value – This study extends prior work by examining the relationship between CI, company strategy, products and services offered and the manner in which companies action's can affect CI.

Serious accidents, which occurred in France in road tunnels in the 2000’s, have revealed specific risks related to tunnels, along with safety management issues. The lessons learned analyses are one resource used by tunnel operators, supported by the French Tunnel Research Centre (CETU), to improve safety management. The question raised in this paper is how these processes are linked to the actual experience sharing processes and collective safety management. Based on careful analysis of the changeover briefings of tunnel control station operators, we aim to show what makes them a means for sharing feedback, managing safety and building a collective structure. We will thus highlight the strength of communication dynamics in driving a formal lessons learned approach, in order to design innovative safety management tools within a high-risk industrial environment., Les accidents graves survenus en France dans les tunnels routiers dans les années 2000 ont mis en évidence des risques spécifiques liés au contexte « tunnel » et des enjeux concernant la gestion de la sécurité. Les dispositifs de retour d’expérience sont un des moyens mobilisés par les exploitants de tunnel, accompagnés par le Centre d’Etude des Tunnels (CETU), pour améliorer leur gestion de la sécurité. En quoi ces dispositifs sont en lien avec les pratiques réelles de partage d’expérience et de gestion collective de la sécurité, telle est la question soulevée dans cette communication. Partant d’une analyse des communications de relève des opérateurs de supervision d’un poste de commande de tunnel, il s’agira de montrer comment les relèves sont un lieu de partage d’expérience, de gestion de la sécurité, et de construction du collectif. Il s’agira ainsi de mettre en relief comment les dynamiques de la relève peuvent alimenter les démarches de retour d’expérience formelles pour concevoir des dispositifs de gestion de la sécurité innovants dans des contextes de risques industriels importants.

ISBN 978-1-4673-2498-4; International audience; Heterogeneous hierarchical architectures result from the interconnection of several heterogeneous MPSoCs through an efficient communication infrastructure. Each communication between two processing units requires the use of hardware devices managed by a software driver responsible to initialize, handle and complete the communication. This paper describes a multi-device driver synthesis flow based on available communication paths of the architecture. A small set of generic driver templates is available in a driver library. The flow is in charge to select one correct driver template from the library, and then to configure and specialize it in order to produce the source code. The effectiveness of our approach is illustrated by a significant example.

International audience; Chaotic digital transmissions have recently emerged as a way to improve the security and privacy of digital transmissions. In this paper, we propose a new approach to estimate the transmitted symbols on the receiver side. This approach, that we call “Symbolic Matching”, consists in matching vectors built from the received signal with a symbolic model of the chaotic oscillator trajectories. Simulation results are also provided and they show that low error rates are obtained.

This paper is devoted to static load balancing techniques for mapping iterative algorithms onto heterogeneous clusters. The application data is partitioned over the processors. At each iteration, independent calculation- s are carried out in parallel, and some communications take place. The question is to determine how to slice the application data into chunks, and to assign these chunks to the processors, so that the total execution time is minimized. We establish a complexity result that assesses the difficulty of this problem, and we design practical heuristics that provide efficient distribution schemes.; Ce rapport est consacré à l’ équilibrage de charge pour algorithmes itératifs sur plateformes hétérogènes. Les données sont réparties sur l’ensemble des ressources à chaque itération, les calculs indépendants sont transmis en parallèle et les communications ont lieu. Le problème est de déterminer comment partitionner les données et comment les répartir sur les ressources pour que le temps total d’exécution soit minimal. Nous avons démontré un résultat de complexité qui établit la difficulté de ce problème, et nous proposons des heuristiques pratiques qui prouvent l’efficacitéé de la distribution.

International audience; A FRENCH PERSPECTIVE ON IDENTITY This paper introduces a distinct approach to organizational identity study which has lately been known as the 'French School of Thought' (Moingeon and Ramanantsoa, 1997). Larçon and Reitter (1979) defined identity as a set of interdependent characteristics of an organization which give the organization specificity, distinctiveness and coherence over time. Following this path-setting definition, a 'tradition' of identity research emerged at HEC Business School, Paris. This definition is broadly similar to that of Albert and Whetten (1985) which is regarded as the foundation stone of the OB (organizational behavior) approach to identity (Whetten and Godfrey, 1998). However, there are some specificities to the French school of thought which will be illustrated below in the context of the study of firms merger, notably, this case illustrates the importance of a notion of organizational imaginaire, a concept somewhat linked to that of organizational images (Dutton et al., 1994)

Real time interapplication communications are a key feature in musical multi-task operating systems. Independent applications can therefore be connected and collaborate by exchanging messages and data through communication channels. All these collaborating applications define a virtual network the user can dynamically configurate. The topology of such virtual network specifies the way applications can be connected together. This paper introduces a new hierarchical topology we recently implemented in our MidiShare multi-task operating system. This approach offers several advantages and particularly when a large number of applications are involved or in a multi-user context.