Developing and Evaluating Intermodal E-Sharing Services – A Multi-method Approach

Different studies assume that travel behavior and mobility patterns of people may change within the next years: multimodal and intermodal usage of transport modes are getting more and more important. We expect a great potential for sharing services especially on intermodal trips. We aim at developing and evaluating intermodal electric mobility management concepts from the customer perspective. Since conventional approaches and singular methods are not appropriate, we adopted a multi-method approach consisting of five parts: (1) supply concepts are developed, (2) vehicle requirements for intermodal sharing are identified, (3) intermodal trip information is collected, (4) an agent based model and a macroscopic demand model are developed further in order to represent intermodal trips and e-vehicles and to evaluate several supply concepts, and (5) the impact and acceptance of modern and flexible mobility services like carsharing, bikesharing or new electric vehicle concepts (e.g. segways or light cars) is assessed and evaluated. The proposed methodology can be used for the development of customer oriented and attractive intermodal sharing services. Hence, the model results are essential for the evaluation and economic appraisal of e-sharing services from the supplier perspective. The proposed methodology can be applied to other cities and regions

Crossover between Rayleigh-Taylor Instability and turbulent cascading atomization mechanism in the bag-breakup regime

The question whether liquid atomization (or pulverization) resorts to instability dynamics (through refinements of Rayleigh-Plateau, Rayleigh-Taylor or Kelvin-Helmholtz mechanism) or to turbulent cascades similar to Richardson and Kolmogorov first ideas seems to be still open. In this paper, we report experimental evidences that both mechanisms are needed to explain the spray drop PDF obtained from an industrial nozzle. Instability of Rayleigh-Taylor kind governs the size of the largest droplets while the smallest ones obey a PDF given by a turbulent cascading mechanism resulting in a log-L\'evy stable law of stability parameter close to 1.68. This value, very close to the inverse of the Flory exponent, can be related to a recent model for intermittency modeling stemming from self-avoiding random vortex stretching.Comment: new alpha version (precedent was a draft

Kidney allograft rejection is associated with an imbalance of B cells, regulatory T cells and differentiated CD28-CD8+ T cells: analysis of a cohort of 1095 graft biopsies

IntroductionThe human immune system contains cells with either effector/memory or regulatory functions. Besides the well-established CD4+CD25hiCD127lo regulatory T cells (Tregs), we and others have shown that B cells can also have regulatory functions since their frequency and number are increased in kidney graft tolerance and B cell depletion as induction therapy may lead to acute rejection. On the other hand, we have shown that CD28-CD8+ T cells represent a subpopulation with potent effector/memory functions. In the current study, we tested the hypothesis that kidney allograft rejection may be linked to an imbalance of effector/memory and regulatory immune cells.MethodsBased on a large cohort of more than 1000 kidney graft biopsies with concomitant peripheral blood lymphocyte phenotyping, we investigated the association between kidney graft rejection and the percentage and absolute number of circulating B cells, Tregs, as well as the ratio of B cells to CD28-CD8+ T cells and the ratio of CD28-CD8+ T cells to Tregs. Kidney graft biopsies were interpreted according to the Banff classification and divided into 5 biopsies groups: 1) normal/subnormal, 2) interstitial fibrosis and tubular atrophy grade 2/3 (IFTA), 3) antibody-mediated rejection (ABMR), 4) T cell mediated-rejection (TCMR), and 5) borderline rejection. We compared group 1 with the other groups as well as with a combined group 3, 4, and 5 (rejection of all types) using multivariable linear mixed models.Results and discussionWe found that compared to normal/subnormal biopsies, rejection of all types was marginally associated with a decrease in the percentage of circulating B cells (p=0.06) and significantly associated with an increase in the ratio of CD28-CD8+ T cells to Tregs (p=0.01). Moreover, ABMR, TCMR (p=0.007), and rejection of all types (p=0.0003) were significantly associated with a decrease in the ratio of B cells to CD28-CD8+ T cells compared to normal/subnormal biopsies. Taken together, our results show that kidney allograft rejection is associated with an imbalance between immune cells with effector/memory functions and those with regulatory properties

Shifting the limits in wheat research and breeding using a fully annotated reference genome

Introduction: Wheat (Triticum aestivum L.) is the most widely cultivated crop on Earth, contributing about a fifth of the total calories consumed by humans. Consequently, wheat yields and production affect the global economy, and failed harvests can lead to social unrest. Breeders continuously strive to develop improved varieties by fine-tuning genetically complex yield and end-use quality parameters while maintaining stable yields and adapting the crop to regionally specific biotic and abiotic stresses. Rationale: Breeding efforts are limited by insufficient knowledge and understanding of wheat biology and the molecular basis of central agronomic traits. To meet the demands of human population growth, there is an urgent need for wheat research and breeding to accelerate genetic gain as well as to increase and protect wheat yield and quality traits. In other plant and animal species, access to a fully annotated and ordered genome sequence, including regulatory sequences and genome-diversity information, has promoted the development of systematic and more time-efficient approaches for the selection and understanding of important traits. Wheat has lagged behind, primarily owing to the challenges of assembling a genome that is more than five times as large as the human genome, polyploid, and complex, containing more than 85% repetitive DNA. To provide a foundation for improvement through molecular breeding, in 2005, the International Wheat Genome Sequencing Consortium set out to deliver a high-quality annotated reference genome sequence of bread wheat. Results: An annotated reference sequence representing the hexaploid bread wheat genome in the form of 21 chromosome-like sequence assemblies has now been delivered, giving access to 107,891 high-confidence genes, including their genomic context of regulatory sequences. This assembly enabled the discovery of tissue- and developmental stage–related gene coexpression networks using a transcriptome atlas representing all stages of wheat development. The dynamics of change in complex gene families involved in environmental adaptation and end-use quality were revealed at subgenome resolution and contextualized to known agronomic single-gene or quantitative trait loci. Aspects of the future value of the annotated assembly for molecular breeding and research were exemplarily illustrated by resolving the genetic basis of a quantitative trait locus conferring resistance to abiotic stress and insect damage as well as by serving as the basis for genome editing of the flowering-time trait. Conclusion: This annotated reference sequence of wheat is a resource that can now drive disruptive innovation in wheat improvement, as this community resource establishes the foundation for accelerating wheat research and application through improved understanding of wheat biology and genomics-assisted breeding. Importantly, the bioinformatics capacity developed for model-organism genomes will facilitate a better understanding of the wheat genome as a result of the high-quality chromosome-based genome assembly. By necessity, breeders work with the genome at the whole chromosome level, as each new cross involves the modification of genome-wide gene networks that control the expression of complex traits such as yield. With the annotated and ordered reference genome sequence in place, researchers and breeders can now easily access sequence-level information to precisely define the necessary changes in the genomes for breeding programs. This will be realized through the implementation of new DNA marker platforms and targeted breeding technologies, including genome editing

On the classification of droplet breakup in an exterior stream

International audienc

Contribution à l'étude de la pulvérisation et de la dispersion dans l'air de fluides newtoniens et non-newtoniens (application aux largages aériens d'eau et de fluide retardant)

Cette thèse est consacrée à l'étude du largage aérien d'eau et de mélange retardant. Les enjeux se situent à plusieurs niveaux: de la compréhension qualitative des phénomènes à la prédiction de l'influence de la formulation et de la rhéologie du fluide employé sur sa répartition au sol; ce sujet touche à de nombreux domaines de la mécanique: turbulence et mécanique statistique, mécanique des fluides diphasiques et rhéologie. La première partie de cette thèse est consacrée à l'étude des ordres de grandeurs du largage aérien d'eau et de retardant. On met en évidence la similitude de ce problème avec celui du mélange turbulent dans l'instabilité de Rayleigh-Taylor. On aborde ensuite l'étude de la théologie du mélange retardant utilisé par la sécurité civile française.On met cette fois-ci en évidencé l'importance de la floculation par déplétion, facteur qui compense en partie les effets viscoélastiques dus à la présence de gomme Guar. Avant d'aborder la partie simulation numérique, on effectue la modélisation de la fragmentation d'un liquide à grand nombre de Weber. Cette approche, qui fait appel à la notion de processus auto-similaire, permet de rendre compte de l'important nombre de petites gouttes dans un spray turbulent. On peut ainsi obtenir de façon quantitative un certain nombre de grandeurs caractéristiques du spray (diamètre moyen de Sauter, densité d'interface) On aborde alors une formulation mathématique rigoureuse de la mécanique des fluides dipbasiques par prise de moyenne spatiale. Ce qui aboutit à une dérivation d'une équation de transport pour la densité d'interfaces. Les équations de fermeture nécessaires sont alors dérivées en utilisant une thermodynamique des phénomènes irréversibles étendue. On effectue enfin la simulation du largage aérien d'eau et de retardant par un avion porteur d'eau. Cela se fait par découpage du problème en deux étapes: ouverture de la trappe puis dispersion d~ nuage. Le lien entre les deux étapes est obtenu par une méthode de changement de maillage inspirée des filtrages successifs de Germano en Simulation des grandes échelles.The topic ofthis thesis is the modeling of the aerial dropping ofwater and retardant fluid by an airplane on a wildland fire. There are several levels of understanding: from qualitative description to fine prediction of the influence of the retardant fluid rheology on the spreading of the cloud. Most domains of fluid mechanics are concerned: turbulence and statistical mechanics, multiphase flows and complex fluid rheology. First part of this thesis is a bibliographical and qualitative study of characteristic scales of the problem. Emphasis is put on the similarity between aerial dropping and turbulent mixing in the Rayleigh-Taylor instabi~. Kinetic and potential energy in a typical dropping are around three and two mega Joules respectively and Reynolds number may be as high as 109, ln the second part, French retardant fluid rheological properties are studied. lt is a mixture of water, ammonium polyphosphate, attapulgites clay, guar gum and iron oxides. lt bas a complex rheological behavior but elasticity is quickly decreasing under shear stress so it can be efficiently modeled using a simple power-law viscosity. Third part develops a self-sitnilar stochastic process akin to a fragmentation equation whose solutions are given using P. Lévy stable laws. lt is then shown from comparison with experimental data that it helps in fitting some experimental data in atomization study and may especially give a better fit to the small drop part of the p.d.f. Other spray characteristics (like intensity or Sauter mean diameter) may be efficiently computed using these p.d.f. Fourth part is a derivation of one-fluid and two-fluid macroscopic model of biphasic medium by averaging the microscopic equations. The notion of interfacial area concentration is developed in Ibis framework. A balance equation is calculated and necessary closure equations are obtained using extended irreversible thermodynatnics. ln the fifth part, simulations of the dropping were divided in two stages: a trap opening stage computed on a fine mesh and a cloud spreading stage computed on a coarser mesh. Final solution of the trap opening stage is used to initialize the cloud spreading stage using a mesh coarsening method based on Germano's generalized central moments in order to compute new turbulent quantities.NANCY/VANDOEUVRE-INPL (545472102) / SudocSudocFranceF

Étude des Mécanismes de Transfert des Nanoparticules au travers d'une Barrière de Confinement Dynamique

Les travaux de thèse ont permis de quantifier l'efficacité de confinement de deux dispositifs distincts (un poste de sécurité microbiologique et une sorbonne classique) lors de la production simultanée de nanoaérosols et d'un gaz traceur (SF6). Deux techniques de mesure différentes ont été exploitées : la première basée sur la mesure de la distribution granulométrique de l'aérosol s'échappant (SMPS-C), l'autre reposant sur la détection de fluorescence d'échantillons prélevés (fluorescéine sodée utilisée comme marqueur des nanoparticules). Les résultats ont permis d'établir une forte corrélation entre le comportement d'un nanoaérosol et celui d'un gaz traceur lorsqu'ils sont émis simultanément dans une enceinte ventilée. Plus encore, on a observé une rétrodiffusion gazeuse quasiment deux fois plus importante pour le gaz traceur que pour les nanoparticules testées dans différentes configurations. Le dépôt ainsi que l'agglomération présents dans le cas du transport d'un nuage de nanoparticules peuvent expliquer ces écarts dans le niveau global de confinement obtenu. Cependant, ce constat n'est pas un gage de protection suffisante dans la mesure où il n'existe pas de valeur spécifique de référence lors de l'exposition à des nanoparticules. Il est alors utile de respecter les règles de bonne conduite qui ont été définies dans de nombreux guides INRS ou au travers de multiples études de l'IRSN. En plus de ces études expérimentales, le banc d'essai développé à l'INRS a fait l'objet d'une simulation numérique permettant de valider un modèle eulérien de transport et de dépôt implémenté dans un code de CFD destiné à modéliser le comportement d'un nanoaérosol. Les résultats numériques/expérimentaux sont concordants ; les ordres de grandeur des niveaux de confinement atteints sont comparablesThe thesis works have enabled us to quantify the containment efficiency of two devices (a microbiological safety cabinet and classical fume hood) during the simultaneous production of nanoaerosols and a tracer gas (SF6). Two different measurement techniques were used: the first based on the measurement of particle size distribution of the escaping aerosol (SMPS-C), the other based on the detection of fluorescence of samples (sodium fluorescein used as marker of nanoparticles). The results have established a strong correlation between the behavior of a nanoaerosols and the tracer gas when they are emitted simultaneously in a ventilated enclosure. More, we observed that tracer gas back diffusion was almost twice greater than for nanoparticles back diffusion in all the tested configurations. The deposit and the agglomeration present in the case of transport of a cloud of nanoparticles can explain these differences in the overall level of containment. However, this observation does not guarantee sufficient protection since there is no specific reference value for nanoparticle exposure. It is useful to observe the guidelines that have been defined in many INRS publications or through IRSN studies. In addition to these experimental studies, the test-rig developed at INRS has been numerically simulated to validate an eulerian transport and deposition model implemented in a CFD code for modeling the behavior of a nanoaerosol. Numerical and experimental results are concordant; orders of magnitude for the achieved containment levels are comparableMETZ-SCD (574632105) / SudocNANCY1-Bib. numérique (543959902) / SudocNANCY2-Bibliotheque electronique (543959901) / SudocNANCY-INPL-Bib. électronique (545479901) / SudocSudocFranceF