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  • Open Access English
    Authors: 
    Uwe John; Yameng Lu; Sylke Wohlrab; Marco Groth; Jan Janouškovec; Gurjeet S. Kohli; Felix Christopher Mark; Ulf Bickmeyer; Sarah Farhat; Marius Felder; +7 more
    Publisher: HAL CCSD
    Countries: Germany, France, France, France
    Project: EC | MICRO B3 (287589)

    Dinoflagellates are microbial eukaryotes that have exceptionally large nuclear genomes; however, their organelle genomes are small and fragmented and contain fewer genes than those of other eukaryotes. The genus Amoebophrya (Syndiniales) comprises endoparasites with high genetic diversity that can infect other dinoflagellates, such as those forming harmful algal blooms (e.g., Alexandrium). We sequenced the genome (~100 Mb) of Amoebophrya ceratii to investigate the early evolution of genomic characters in dinoflagellates. The A. ceratii genome encodes almost all essential biosynthetic pathways for self-sustaining cellular metabolism, suggesting a limited dependency on its host. Although dinoflagellates are thought to have descended from a photosynthetic ancestor, A. ceratii appears to have completely lost its plastid and nearly all genes of plastid origin. Functional mitochondria persist in all life stages of A. ceratii, but we found no evidence for the presence of a mitochondrial genome. Instead, all mitochondrial proteins appear to be lost or encoded in the A. ceratii nucleus. The parasitic marine dinoflagellate Amoebophrya is the first known eukaryote with aerobic mitochondria without a genome.

  • Closed Access English
    Authors: 
    Nore, C.; Leorat, J.; Guermond, J.-L.; Giesecke, A.;
    Publisher: HAL CCSD
    Countries: Germany, France

    It has been observed that dynamo action occurs in the von-Karman-Sodium (VKS) experiment only when the rotating disks and the blades are made of soft iron. The purpose of this paper is to numerically investigate the role of soft iron in the VKS dynamo scenario. This is done by using a mean field model based on an axisymmetric mean flow, a localized permeability distribution, and a localized α-effect modeling the action of the small velocity scales between the blades. The action of the rotating blades is modeled by an axisymmetric effective permeability field. Key properties of the flow giving to the numerical magnetic field a geometric structure similar to that observed experimentally are identified. Depending on the permeability of the disks and the effective permeability of the blades, the dynamo that is obtained is either oscillatory or stationary. Our numerical results confirm the leading role played by the ferromagnetic impellers. A scenario for the VKS dynamo is proposed.

  • Publication . Conference object . Contribution for newspaper or weekly magazine . 2015
    Open Access English
    Authors: 
    Mahmoud Jazayerifar; Isaac Sackey; Robert Elschner; F. Da Ros; Thomas Richter; Christian Meuer; Christophe Peucheret; Colja Schubert; Klaus Petermann;
    Publisher: IEEE
    Countries: France, Denmark, France

    International audience; The deployment of phase-insensitive fiber-optic parametric amplifiers (PI-FOPAs) as inline amplifiers in long-haul WDM transmission systems is discussed, and it is outlined how to design PI-FOPAs to be a valuable upgrade option for this application.

  • Publication . Preprint . Research . Other literature type . Article . 2019
    Open Access English
    Authors: 
    LHCb collaboration; Aaij, R.; Beteta, C. Abellán; Adeva, B.; Adinolfi, M.; Aidala, C. A.; Ajaltouni, Z.; Akar, S.; Albicocco, P.; Albrecht, J.; +190 more
    Publisher: RWTH Aachen University
    Countries: Germany, France

    An angular analysis of $B^0\to J/\psi K^+\pi^-$ decays is performed, using proton-proton collision data corresponding to an integrated luminosity of 3~${\rm fb}^{-1}$ collected with the LHCb detector. The $m(K^+\pi^-)$ spectrum is divided into fine bins. In each $m(K^+\pi^-)$ bin, the hypothesis that the three-dimensional angular distribution can be described by structures induced only by $K^\ast$ resonances is examined, making minimal assumptions about the $K^+\pi^-$ system. The data reject the $K^\ast$-only hypothesis with a large significance, implying the observation of exotic contributions in a model-independent fashion. Inspection of the $m(J/\psi\pi^-)$ versus $m(K^+\pi^-)$ plane suggests structures near $m(J/\psi\pi^-)=4200$~MeV and 4600~MeV. Comment: All figures and tables, along with any supplementary material and additional information, are available at http://lhcbproject.web.cern.ch/lhcbproject/Publications/LHCbProjectPublic/LHCb-PAPER-2018-043.html

  • Publication . Doctoral thesis . 2015 . Embargo End Date: 10 Dec 2015
    Open Access English
    Authors: 
    Wang, Yong;
    Publisher: Universität des Saarlandes
    Countries: Germany, France

    Accès restreint aux membres de l'Université de Lorraine jusqu'au 2016-02-16; Copper oxide (Cu2O, Cu4O3 and CuO) thin films have been deposited on unmatched substrates by sputtering at room temperature. The influence of oxygen flow rate and total pressure on the film structure and preferred orientation has been studied. The total pressure is a relevant parameter to control the texture of Cu2O and Cu4O3 films, while the oxygen flow rate is effective to tune the preferred orientation of CuO films. Local epitaxial growth, where epitaxial relationship exists in columns of sputtered films, has been observed in Cu2O and Cu4O3 films by using a seed layer. The seed layer will govern the growth orientation of top layer via the local epitaxy, independently of the deposition conditions of top layer. Unusual microstructure that both phases have the vertically aligned columnar growth has been evidenced in biphase Cu2O and Cu4O3, which may relate to the local epitaxial growth of Cu2O. The lower resistivity than that in single phase films has been observed in this biphase film. Annealing in air can increase the transmittance of Cu2O films in visible region by the reduction of the impurity scattering, while the optical band gap is enlarged due to the partial removal of defect band tail. The optical properties and electronic structure of copper oxides calculated by GW approach with an empirical on-site potential for Cu d orbital, are in good accordance with experimental results from optical absorption, photoemission and electron energy loss spectroscopies; Des films minces d’oxydes de cuivre (Cu2O, Cu4O3 et CuO) ont été déposés à température ambiante sur des substrats en verre et en silicium par pulvérisation magnétron réactive. Une attention particulière a été portée à l’influence des conditions de synthèse (débit d’oxygène et pression totale) sur la structure et l’orientation préférentielle des dépôts. La pression totale est le paramètre principal influençant la texture des films de Cu2O et de Cu4O3. En revanche l’orientation préférentielle des films de CuO est contrôlée par le débit d’oxygène. Pour des films de Cu2O et de Cu4O3, un phénomène de croissance épitaxique locale (CEL) a été mis en évidence. Il résulte de l’utilisation d’une première couche qui joue le rôle d’une couche de germination lors du processus de croissance. Ainsi, les films peuvent croître avec une texture donnée indépendamment de leurs conditions de synthèse. Cet effet de CEL a été mis à profit pour élaborer des films biphasés (Cu2O + Cu4O3) qui présentent une microstructure originale. L’augmentation de la transmittance optique et du gap optique de films de Cu2O a été rendue possible par des traitements thermiques dans l’air qui permettent de diminuer la densité de défauts dans les films. Finalement, les propriétés optiques et la structure électronique des oxydes de cuivre qui ont été calculées par la méthode GW sont en accord avec des résultats expérimentaux obtenus par absorption optique, photoémission et spectroscopie de perte d’énergie des électrons.

  • Publication . Article . Other literature type . 2012
    Open Access English
    Authors: 
    Cesare de Filippo; Koen Bostoen; Mark Stoneking; Brigitte Pakendorf;
    Publisher: HAL CCSD
    Countries: Belgium, France
    Project: EC | KONGOKING (284126)

    International audience; The expansion of Bantu languages represents one of the most momentous events in the history of Africa. While it is well accepted that Bantu languages spread from their homeland (Cameroon/Nigeria) approximately 5000 years ago (ya), there is no consensus about the timing and geographical routes underlying this expansion. Two main models of Bantu expansion have been suggested: The 'early-split' model claims that the most recent ancestor of Eastern languages expanded north of the rainforest towards the Great Lakes region approximately 4000 ya, while the 'late-split' model proposes that Eastern languages diversified from Western languages south of the rainforest approximately 2000 ya. Furthermore, it is unclear whether the language dispersal was coupled with the movement of people, raising the question of language shift versus demic diffusion. We use a novel approach taking into account both the spatial and temporal predictions of the two models and formally test these predictions with linguistic and genetic data. Our results show evidence for a demic diffusion in the genetic data, which is confirmed by the correlations between genetic and linguistic distances. While there is little support for the early-split model, the late-split model shows a relatively good fit to the data. Our analyses demonstrate that subsequent contact among languages/populations strongly affected the signal of the initial migration via isolation by distance.

  • Open Access English
    Authors: 
    Hasan Koç; Kurt Sandkuhl;
    Publisher: HAL CCSD
    Country: France
    Project: EC | CAAS (611351)

    Part 1: Regular Papers; International audience; Today’s enterprises face the need to develop user-specific solutions due to the disruptive technologies and competition in the market. Intangibility of services and service-orientation fosters creation of flexible solutions by innovating business models, service processes and service products. Capabilities are perceived as measuring indicator of service orientation in enterprises and one requirement for business model innovation. This paper investigates how design of capabilities can help enterprises to offer novel services. To do so, we analyze the degree of innovation before and after applying the capability-driven development (CDD), which is a methodological and technological enterprise modelling approach. Based on observations from two industrial cases affected from the main forces that disturb the business terrain, the paper concludes that CDD helps enterprises to innovate their digital services by causing changes mainly on business model and service process levels.

  • Open Access English
    Authors: 
    Jérémy Vanhelst; Laurent Béghin; Alain Duhamel; Stefaan De Henauw; Jonatan R. Ruiz; Anthony Kafatos; Odysseas Androutsos; Kurt Widhalm; Beatrice Mauro; Michael Sjöström; +2 more
    Publisher: HAL CCSD
    Country: France

    International audience; Background & aims: The aim of this study was to assess the diet quality awareness and associated factors in a large sample of European adolescents.Methods: The study included 3389 healthy adolescents, aged 12.5–17.5 years, who participated in the Healthy Lifestyle in Europe by Nutrition in Adolescence (HELENA) Study. The adolescents' diet quality was based on repeated 24 h recalls and scored into a Diet Quality Index for Adolescents (DQI-A) considering four components: meal, equilibrium, diversity and quality. A self-rated diet quality questionnaire was administered to adolescents to assess their dietary awareness. The association of DQI-A with dietary awareness was studied using a linear mixed model including the center as the random effect and dietary awareness as the fixed effect.Results: There was a positive association between DQI-A scores and diet quality perception levels (p < 0.0001). The mean DQI-A was 59.0 (SD = 14.8) in adolescents with a low dietary awareness compared with 65.4 (SD = 12.6) in adolescents with high dietary awareness (p < 0.0001). Similar results were found for all the DQI components. When analyses were stratified, we found a significant heterogeneity across the nutritional status, with no significant association between DQI-A and dietary awareness level in obese adolescents, but a positive association in overweight, normal and undernourished groups. We found also a significant heterogeneity associated with the lunch location (school or home). No other factor affected dietary awareness (gender, pubertal status and maternal educational level).Conclusion: European adolescents evaluate well their food quality whatever their pubertal status, gender and parental educational level, except for the obese who are not able to assess their diet quality. Improving the dietary awareness in obese adolescents might help to induce behavioral changes.

  • English
    Authors: 
    Abdallah Abou-Taouk; Benjamin Farcy; Pascale Domingo; Luc Vervisch; Suresh Sadasivuni; Lars-Erik Eriksson;
    Publisher: HAL CCSD
    Country: France

    WOS:000375478200002; International audience; A methodology is discussed to automatically determine the parameters of closed budget equations for chemical species mass fractions and energy, in order to simulate spatially filtered flames as required in large eddy simulation (LES). The method accounts for the effects of LES filtering on chemistry and transport by simultaneously optimizing, for a reduced number of species, the Arrhenius reaction rates and a correction to mixture-averaged molecular diffusion coefficients. The objective is to match, for a given filter size, spatially filtered canonical one-dimensional flames simulated with detailed chemistry solutions. This approach is designed for quite well-resolved LES, in which most of the unresolved fluctuations result from flame thickening due to spatial filtering, thus featuring weak levels of sub-grid scale flame wrinkling. Methane-air partially premixed combustion is addressed. A four-step reduced reaction mechanism involving seven species is developed along with mass and heat molecular transport properties. The optimization is performed at atmospheric pressure and at 3 bar, for ranges of fresh gas temperatures [300-650 K] and equivalence ratios [0.4-1.2]. Comparisons with the filtered detailed chemistry solution of a planar propagating front show that the laminar flame speed, the adiabatic flame temperature, the species profiles in the reaction zone, and the flow chemical composition and temperature at equilibrium are adequately predicted. The new sub-grid scale modeling approach is then applied to three-dimensional LES of an industrial gas turbine burner. Good agreement is found between the quantities predicted with LES and experimental data, in terms of flow and flame dynamics, axial velocities, averaged temperatures, and some major species concentrations. Results are also improved compared to previous simulations of the same burner.

  • Open Access English
    Authors: 
    Katharina Immel; Vu-Hieu Nguyen; Arnaud Dubory; Charles-Henri Flouzat-Lachaniette; Roger A. Sauer; Guillaume Haiat;
    Publisher: HAL CCSD
    Country: France

    International audience; Primary stability of cementless implants is crucial for the surgical success and long–term stability. However, primary stability is difficult to quantify in vivo and the biomechanical phenomena occurring during the press–fit insertion of an acetabular cup (AC) implant are still poorly understood. The aim of this study is to investigate the influence of the cortical and trabecular bone Young's moduli Ec and Et, the interference fit IF and the sliding friction coefficient of the bone–implant interface μ on the primary stability of an AC implant. For each parameter combination, the insertion of the AC implant into the hip cavity and consequent pull–out are simulated with a 3D finite element model of a human hemi–pelvis. The primary stability is assessed by determining the polar gap and the maximum pull–out force. The polar gap increases along with all considered parameters. The pull–out force shows a continuous increase with Ec and Et and a non-linear variation as a function of μ and IF is obtained. For μ > 0.6 and IF > 1.4 mm the primary stability decreases, and a combination of smaller μ and IF lead to a better fixation. Based on the patient's bone stiffness, optimal combinations of μ and IF can be identified. The results are in good qualitative agreement with previous studies and provide a better understanding of the determinants of the AC implant primary stability. They suggest a guideline for the optimal choice of implant surface roughness and IF based on the patient's bone quality.

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