• Publicationsclose
• Research dataclose
• Part of book or chapter of book close
• US close
• Mémoires en Sciences de l'Information et de la Communication close
• Hal-Diderot close
• Hyper Article en Ligne close

2013, IX, 349 p. 79 illus., 55 in color; International audience; We discuss models that astrochemists have developed to study the chemical composition of the interstellar medium. These models aim at computing the evolution of the chemical composition of a mixture of gas and dust under astrophysical conditions. These conditions, as well as the geometry and the physical dynamics, have to be adapted to the objects being studied because different classes of objects have very different characteristics (temperatures, densities, UV radiation fields, geometry, history etc); e.g., proto-planetary disks do not have the same characteristics as proto-stellar envelopes. Chemical models are being improved continually thanks to comparisons with observations but also thanks to laboratory and theoretical work in which the individual processes are studied.

Increases in arterial stiffness and pulse pressure are typical features of the arterial stiffness during aging and are associated with increased risk of cardiovascular complications. Cellular and molecular determinants of arterial stiffness have not been completely elucidated. Clinically, the carotid-femoral pulse wave velocity (PWV) is the gold standard parameter of arterial stiffness. A recent genome-wide scan of the Framingham Heart Study population has shown that arterial stiffness and mean and pulsatile components of blood pressure are heritable and map to separate the genetic loci in humans, suggesting that distinct genes may modulate these two phenotypes. This chapter details the recent knowledge on the influence of genetic determinants and telomere length on the development of age-related phenotypes. Recent genetic studies have revealed specific genes contributing to arterial stiffening. Available data on genome-wide association (GWA) have been initiated on PWV and have identified common genetic variation in specific loci or single-nucleotide polymorphisms (SNP) significantly associated with PWV. Telomere length at birth is strongly determined genetically and is the main determinant of leukocytes’ telomere length (LTL) later in life. Short LTL is associated with increased risk of stiffness and atherosclerosis of the carotid artery, atherosclerotic heart disease, and diminished survival in the elderly.

International audience; We describe an approach to extract 13C-labeled sugars (glucose, fructose, maltose, sucrose, myo-inositol as well as glucose from starch) from plant tissues and to analyze their isotopomer distribution by gas chromatography–mass spectrometry (GC-MS). Sugars are derivatized with N,O-bis(trimethylsilyl) trifluoroacetamide (BSTFA) into their Si(CH3)3 derivatives. Electronic and chemical ionizations are used to obtain suitable fragments for metabolic flux analysis (MFA). Unique fragments are identified by computer simulation and experimental verification with labeled standards. Linear equations for separating information from glucosyl and fructosyl moieties of sucrose are presented. Finally, mass distributions are corrected for natural isotope abundance using a home-written program. The method is illustrated by sugar isotopomer analysis of 13C-labeled rapeseed embryos.

[p. 445] THE SUBJECT OF this paper is a collection of essays composed, in the words of the title "as the brush goes," by Sŏp'o, that is, by Kim Manjung (1637-1692). He is well known, as the author of a masterpiece of Korean fiction, the novel Nine Cloud Dream (Kuunmong). He is also credited with another novel, less famous but not less interesting, The Record of a Southern Journey (Namjŏng ki), which is especially well documented and on which I have already published several articles.

International audience; Adaptive learning support for learners becomes very important in the context of increasing re-use of resources from heterogeneous and distributed learning repositories. This chapter presents OrPAF, an Adaptive Educational Hypermedia (AEHS) and web-based System which integrates semantic web models and technologies in order to achieve interoperability with e-learning systems. The key feature of OrPAF is the construction of adaptive hypermedia courses: both the course structure and the course content are dynamically generated and adapted to learners. On the one hand, a learning ontology is proposed to describe, at a meta-level, abstract characteristics of an e-learning system. This learning ontology is instantiated to construct learning models: domain model, learner model and pedagogical model. On the other hand, semantic annotations and a semantic relevance measure are proposed to improve the LOM metadata associated to learning resources in order to reuse and share them. The authors tested the prototype on learners in order to evaluate the usability of OrPAF and to determine the conceptual capabilities developed by learners who used it.

International audience; Intracellular production and root exudation of metal ion ligands (MIL) are keys to metal ion mobilization and sequestration by vascular plants. This is well-exemplified by the exudation of phytosiderophores such as mugineic acid and derivatives in the acquisition of Fe (III) and Zn (II) by graminaceous plants. However, the genetic and biochemical mechanism(s) for the mobilization and sequestration of most pollutant metal ions remain unknown, due largely to a lack of knowledge in MIL involved in the process. This information is critically needed for developing and engineering plant-based remediation of metal contamination at DOE, DOD, and other industrial facilities. Here, we investigated the influence of elevated metal (Zn, Cu, Ni, Mn, and Cd) ion treatment on root EMSP sym chap final Printed 4/20/00 2 exudation, tissue MIL profiles, and metal accumulation in Chinese spring (CS) wheat, its 7 genotypes prepared from disomic addition of the wheatgrass chromosomes to CS, and the amphiploid between the two species. Broad-screen and structure elucidating nuclear magnetic resonance spectroscopy and gas chromatography-mass spectrometry were employed to obtain comprehensive profiles of MIL in root exudates and tissues, difficult to achieve with conventional approaches. In addition, thiol-rich peptide profiles were acquired using fluorescent bromobimane tagging and sodium dodecyl sulfate-polyacrylamide gel electrophoresis, while comprehensive metal ion profiles were obtained using X-ray fluorescence. Genotypic covariation was noted between metal ions (Mn, Fe, Cu, and Zn) and such MIL as 2'-deoxymugineic acid and acetate in root exudates and citrate and malate in roots. Profiles of phytochelatin-like peptides also displayed genotypic variations and strong correlation with Cd accumulation. These results suggest possible chromosomal location(s) of gene(s) governing metal ion mobilization and sequestration in wheat.

International audience; Toxoplasma gondii is a highly successful parasite that is thought to infect nearly one third of the world's population. Molecular epidemiology studies have illuminated the population structure of T. gondii strains world-wide and enabled insights into how the parasite is transmitted and the frequency of genetic exchange. Toxoplasma population genetics studies have shown that in North America and Europe, three genotypes have predominated whereas other diverse genotypes have propagated in other parts of the world, particularly in Central and South America. This chapter summarizes the techniques used to understand the population structure of T. gondii and how these techniques have also been helpful in understanding outbreaks of toxoplasmosis. As technology has advanced, more in-depth studies have facilitated our understanding of how differing genotypes can be linked to biological phenotypes including human disease.

International audience; Over the long run, sustained growth is central to poverty reduction. The rapid growth seen in much of the world over the past few decades — notably, but not only, in China and India — has led to an unprecedented reduction in poverty. And, in general, increases in per capita income tend to translate into proportionate increases in income of the poor. As Dollar and Kraay (2002) memorably put it, “Growth Is Good for the Poor.” All the more reason, then, to place sustainability of growth at the center of any poverty reduction strategy.

Private Set Intersection Cardinality (PSI-CA) allows two parties, each holding a set of items, to learn the size of the intersection of those sets without revealing any additional information. To the best of our knowledge, this work presents the first protocol that allows one of the parties to delegate PSI-CA computation to untrusted servers. At the heart of our delegated PSI-CA protocol is a new oblivious distributed key PRF (Odk-PRF) abstraction, which may be of independent interest.