Besançon – Parking de la Mairie

Cette opération située en plein centre urbain aura permis de traiter en 16 mois, 4 000 m2 avant la construction d’un parking (fig. 1). La richesse du site est venue confirmer l’aperçu des sondages et des études documentaires préalables (Gallia Informations, 1987-1988, 2, p. 83) avec l’observation d’une stratigraphie continue d’habitat de La Tène finale (fin du iie s. av. J.-C.) à la fin du iie s. apr. J.-C. et la réoccupation du site par un couvent de Clarisses du milieu du xiiie au xviiie s...

28 THz soliton frequency comb in a continuous-wave pumped fiber Fabry-Perot resonator

We report the generation of an optical frequency comb featuring 28 THz bandwidth, sustained by a single 80 fs cavity soliton recirculating in a fiber Fabry-Perot resonator. This large spectrum is comparable to frequency combs obtained with microresonators operating in the anomalous dispersion regime. Thanks to the compact design and the easy coupling of the resonator, cavity solitons can be generated in an all-fiber experimental setup with a continuous wave pumping scheme. We also observe the generation of a dispersive wave at higher frequencies which is supported by higher-order dispersion. These observations align remarkably well with both numerical simulations and the established theory of cavity solitons.Comment: 6 pages, 6 figure

Spectral density of phase noise inter-laboratory comparison final results

This paper reports main results of the phase noise comparison that has been performed between october 2005 and december 2006, using two oscillators at 5 and 100 MHz and un DRO at 3.5 GHz. The problem is not to compare the performances of several oscillators, but to compare and to make an evaluation of the uncertainties, and of course the resolution and the reproducibility of the measurements. This comparison allow us to determine the ability to get various systems traceable together in order to increase the trust that one can have in phase noise measurements

Computing with bacterial constituents, cells and populations: from bioputing to bactoputing

The relevance of biological materials and processes to computing—aliasbioputing—has been explored for decades. These materials include DNA, RNA and proteins, while the processes include transcription, translation, signal transduction and regulation. Recently, the use of bacteria themselves as living computers has been explored but this use generally falls within the classical paradigm of computing. Computer scientists, however, have a variety of problems to which they seek solutions, while microbiologists are having new insights into the problems bacteria are solving and how they are solving them. Here, we envisage that bacteria might be used for new sorts of computing. These could be based on the capacity of bacteria to grow, move and adapt to a myriad different fickle environments both as individuals and as populations of bacteria plus bacteriophage. New principles might be based on the way that bacteria explore phenotype space via hyperstructure dynamics and the fundamental nature of the cell cycle. This computing might even extend to developing a high level language appropriate to using populations of bacteria and bacteriophage. Here, we offer a speculative tour of what we term bactoputing, namely the use of the natural behaviour of bacteria for calculating

Signatures of mutational processes in human cancer.

All cancers are caused by somatic mutations; however, understanding of the biological processes generating these mutations is limited. The catalogue of somatic mutations from a cancer genome bears the signatures of the mutational processes that have been operative. Here we analysed 4,938,362 mutations from 7,042 cancers and extracted more than 20 distinct mutational signatures. Some are present in many cancer types, notably a signature attributed to the APOBEC family of cytidine deaminases, whereas others are confined to a single cancer class. Certain signatures are associated with age of the patient at cancer diagnosis, known mutagenic exposures or defects in DNA maintenance, but many are of cryptic origin. In addition to these genome-wide mutational signatures, hypermutation localized to small genomic regions, 'kataegis', is found in many cancer types. The results reveal the diversity of mutational processes underlying the development of cancer, with potential implications for understanding of cancer aetiology, prevention and therapy

Caracterisation hyperfrequene des supraconducteurs a haute temperature critique en vue de l'application a l'oscillateur micro-onde cryogenique

SIGLEAvailable from INIST (FR), Document Supply Service, under shelf-number : T 82338 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

Le femtosat et les étoiles

National audienc

Approche CAO de systèmes optiques-hyperfréquences incluant les performances en bruit

4 pagesNational audienceIl est important de pouvoir modéliser les performances de liaisons et systèmes optiques hyperfréquences, dont leurs performances en termes de bruit de phase, et de comparer ces résultats avec ceux obtenus analytiquement et expérimentalement. Nous avons donc tenté une approche de modélisation utilisant un logiciel CAO : Agilent ADS. Il s'agit d'un logiciel de simulation de circuit hyperfréquences relativement complet, comprenant différentes méthodes du bruit (incluant le bruit de phase). La particularité ici, consiste en l'utilisation de ce logiciel pour simuler des composants optoélectroniques, qui sont décrits par des équivalents électriques ou mathématiques

Phase noise in SiGe HBT amplifiers and applications: Invited talk at IMS workshop (slides only)

International audienceAmplifier residual phase noise, as a tool to study nonlinear noise in transistors : 1) Measurement technique, 2) Specificity of the characterization of SiGe devices, 3)Residual phase noise modelling of SiGe transistors. Application to the design of a two stages low phase noise SiGe amplifier. Application to the phase noise characterization and modelling of new types of microwave frequency stabilization devices : FBAR resonators and optical resonators

Modélisation non linéaire en bruit phase de transistors TBH SiGe

National audienceCe papier présente une modélisation non linéaire en bruit d'un transistor bipolaire SiGe. L'implémentation de sources de bruit non linéaires dans le modèle du transistor est décrite. Ce modèle s'appuie sur l'observation d'un comportement non linéaire de la source de bruit en tension extrinsèque en parallèle à la jonction base émetteur. La validation de ce modèle est effectuée grâce à la mesure du bruit de phase du transistor étudié dans différentes configurations de polarisation et de puissance. Ce modèle a permis la conception d'un amplificateur à faible bruit de phase pour la réalisation d'un oscillateur à très haute pureté spectrale fonctionnant à 10 GHz. Cet amplificateur à deux étages a été conçu en s'appuyant sur le modèle précédent. Les performances obtenues sont d'un très bon niveau, en effet le gain est égal à 8.2 dB et le bruit de phase à 100 kHz de la porteuse de -165dBrad2.Hz-1