Revisiting the Diego Blood Group System in Amerindians: Evidence for Gene-Culture Comigration

International audienceSix decades ago the DI*A allele of the Diego blood group system was instrumental in proving Native American populations originated from Siberia. Since then, it has received scant attention. The present study was undertaken to reappraise distribution of the DI*A allele in 144 Native American populations based on current knowledge. Using analysis of variance tests, frequency distribution was studied according to geographical, environmental, and cultural parameters. Frequencies were highest in Amazonian populations. In contrast, DI*A was undetectable in subarctic, Fuegian, Panamanian, Chaco and Yanomama populations. Closer study revealed a correlation that this unequal distribution was correlated with language, suggesting that linguistic divergence was a driving force in the expansion of DI*A among Native Americans. The absence of DI*A in circumpolar Eskimo-Aleut and Na-Dene speakers was consistent with a late migratory event confined to North America. Distribution of DI*A in subtropical areas indicated that gene and culture exchanges were more intense within than between ecozones. Bolstering the utility of classical genetic markers in biological anthropology, the present study of the expansion of Diego blood group genetic polymorphism in Native Americans shows strong evidence of gene-culture comigration

MapSense: Design and Field Study of Interactive Maps for Children Living with Visual Impairments

We report on the design process leading to the creation of MapSense, a multi-sensory interactive map for visually impaired children. We conducted a formative study in a specialized institute to understand children’s educational needs, their context of care and their preferences regarding interactive technologies. The findings (1) outline the needs for tools and methods to help children to acquire spatial skills and (2) provide four design guidelines for educational assistive technologies. Based on these findings and an iterative process, we designed and deployed MapSense in the institute during two days. It enables collaborations between children with a broad range of impairments, proposes reflective and ludic scenarios and allows caretakers to customize it as they wish. A field experiment reveals that both children and caretakers considered the system successful and empowering

MapSense: multi-sensory interactive maps for children living with visual impairments

We report on the design process leading to the creation of MapSense, a multi-sensory interactive map for visually impaired children. We conducted a formative study in a specialized institute to understand children’s educational needs, their context of care and their preferences regarding interactive technologies. The findings (1) outline the needs for tools and methods to help children to acquire spatial skills and (2) provide four design guidelines for educational assistive technologies. Based on these findings and an iterative process, we designed and deployed MapSense in the institute during two days. It enables collaborations between children with a broad range of impairments, proposes reflective and ludic scenarios and allows caretakers to customize it as they wish. A field experiment reveals that both children and caretakers considered the system successful and empowering

Large-eddy simulations of round jets: effects of initial conditions on self-similarity region

Round jets are computed using large-eddy simulations based on low-dissipation schemes to investigate the influence of initial conditions on their self-similarity regions. Three jets with the same initial parameters except for the diameters yielding Reynolds numbers of 11000, 3600 and 1800 are first considered, then two additional jets at Reynolds number 3600 but with modified initial shear-layer thickness and forcing are calculated. The properties of the mean and turbulent flows are compared

Foamed Nanocomposites for EMI Shielding Applications

INTRODUCTION : The addition of nanoparticles having specific properties inside a matrix with different properties creates a novel material that exhibits hybrid and even new properties. The nanocomposites presented in this paper combine the properties of foamed polymers (inexpensive, lightweight, easy to mould into any desired shape, etc.) with those of carbon nanotubes (CNTs). The addition of any conductive nanoparticles to an otherwise insulating matrix leads to a significant increase of the electrical conductivity. But CNTs have a very high aspect ratio; a much lower content of CNTs is therefore required to get the same conductivity increase as the one obtained with more compact nanoparticles. This is especially interesting for EMI shielding materials since, as will be explained in further details in this chapter, it is desirable for such materials to have a high conductivity but a low dielectric constant, in order to minimize the electromagnetic power outside the shield casing but also to minimize the power reflected back inside the casing, as is explained in section 2. In particular, two parameters of interest when comparing shielding materials are detailed and discussed. The polymer/CNTs nanocomposites were fabricated and characterized using a two-step diagnostic method. They were first characterized in their solid form, i.e. before the foaming process and the most interesting polymer matrices (with embedded CNTs) could be selected. This way, only the promising blends were foamed, therefore avoiding the unnecessary fabrication of a number of foams. These selected blends were foamed and then characterized. The samples, both solid and foamed, are described and their fabrication processes are briefly explained in section 3 while the characterization methods are shown in section 4. A simple electrical model is given and explained in section 5 and an optimized topology for the foams is also proposed in the second part of the same section. The measurement results for the solids and for the mono-layered and multi-layered foams are summarized and discussed in section 6. They are then compared to results obtained using the electrical model presented in the previous section and they are also correlated to rheological characterizations

Evaluating the pronunciation of proper names by four French grapheme-to-phoneme converters

International Speech Communication Association (Isca) - International Astronautical Federation.ISBN : 13 9781604234480.This article reports on the results of a cooperative evaluation of grapheme-to-phoneme (GP) conversion for proper names in French. This work was carried out within the framework of a general evaluation campaign of various speech and language processing devices, including text-to-speech synthesis. The corpus and the methodology are described. The results of 4 systems are analysed: with 12-20% word error rates on a list of 8,000 proper names, they give a fairly accurate picture of the progress achieved, the state-of-the-art and the problems still to be solved, in the domain of GP conversion in French. In addition, the resources and collected data will be made available to the scientific and industrial community, in order to be re-used in future bench-marks

Numerical study of screech generation in a planar supersonic jet

International audienceThe generation of screech tones in an underexpanded jet is investigated by means of compressible large eddy simulation ͑LES͒. A three-dimensional planar geometry is considered with the aim of studying screech radiation in a simple jet configuration, whose physics nevertheless remains similar to that of large-aspect-ratio rectangular jets encountered in experimental surveys. The jet operates at fully expanded Mach number M j = 1.55, with Reynolds number Re h =6ϫ 10 4. The LES strategy is based on explicit selective filtering with spectral-like resolution, and low-dispersion and low-dissipation numerical algorithms are implemented to allow the direct noise computation of the phenomenon. The numerical results are first set against experimental data to establish the consistency of the simulation. It is shown that the flow development and the shock-cell structure are in agreement with experiments of the literature. Furthermore, the upstream acoustic field exhibit harmonic tones that compare correctly to screech tones observed on rectangular jets in terms of frequency, amplitude, and phase shift on either side of the jet. The extrapolation of the LES near-field data to the far field demonstrates that the radiated noise includes the three characteristic noise sources of supersonic shock-containing jets: screech tones, shock-associated noise, and mixing noise, with frequencies and directivities in agreement with experimental observations. Flow visualization of shock/vortex interactions near the third shock-cell finally provides evidences that screech sound sources can be interpreted using the shock-leakage theory. It is shown in particular that the third compression shock within the jet can leak outside through regions of the shear layer with low level of vorticity and results in the production of upstream-propagating sound waves contributing to screech tone radiation

International Law in Crisis: A Qualitative Empirical Contribution to the Compliance Debate

In the aftermath of the terrorist attacks of September 11, 21, Professors Jack Goldsmith and Eric Posner published The Limits of International Law, a potentially revolutionary book that employs rational choice theory to argue that international law is really just “politics” and does not render a “compliance pull” on State decisionmakers. Critics have pointed out that Goldsmith and Posner’s identification of the role of international law in each of their case studies is largely conjectural, and that what is needed is qualitative empirical data that identifies the international law-based arguments that were actually made and the policy-makers’ responses to such arguments. In an effort to fill this gap, with the support of a Carnegie Corporation grant, the author convened a series of meetings and exchanges with the ten living former State Department Legal Advisers to discuss the influence of international law in the formulation of foreign policy during times of crisis. This Article reviews the scholarly debate about the nature of international legal obligation, presents the results of the Legal Advisers’ meetings, and provides an in depth examination of a modern case study involving the treatment of detainees in the war on terror which highlights the importance of these findings

Review of Actinide Decorporation with Chelating Agents

International audienceIn case of accidental release of radionuclides in a nuclear facility or in the environment, internal contamination (inhalation, in-gestion or wound) with actinides represents a severe health risk to human beings. It is therefore important to provide effective che-lation therapy or decorporation to reduce acute radiation damage, chemical toxicity, and late radiation effects. Speciation governs bioavailability and toxicity of elements and it is a prerequisite tool for the design and success of new ligands or chelating agents. The purpose of this review is to present the state-of-the-art of actinide decorporation within biological media, to recall briefly actinide metabolism, to list the basic constraints of actinideeligand for development, to describe main tools developed and used for decorporation studies, to review mainly the chelating agents tested for actinides, and finally to conclude on the future trends in this field. To cite this article: E ´. Ansoborlo et al., C. R. Chimie X 33 (2007). Ó 2007 Académie des sciences. Published by Elsevier Masson SAS. All rights reserved.En cas de rejet accidentel de radionucléides dans une installation nucléaire ou dans l'environnement, il existe un risque de contamination interne (inhalation, ingestion ou blessure) pour l'homme et il est important de pouvoir fournir un traitement thérapeutique par des agents chélatants ou décorporation permettant de réduire la dose, la toxicité chimique et les effets retardés des radiations.La spéciation domine la biodisponibilité et la toxicité des éléments et représente un outil indispensable pour la conception et l'efficacité de nouveaux ligands ou chélatants. Le but de cet article est de présenter l'état de l'art sur la décorporation des actinides en milieu biologique, de rappeler les grandes lignes du métabolisme des actinides, de lister les contraintes indispensables actinide–ligands pour la décorporation, de décrire succinctement les principaux outils expérimentaux ou analytiques utilisés, de passer en revue les principaux ligands testés pour les actinides et de présenter les orientations du futur dans ce domaine

Propagation des ondes infrasonores dans l'atmosphère

Les ondes infrasonores ont la propriété de pouvoir se propager sur des centaines de kilomètres dans l'atmosphère terrestre. Elles sont produites par des évènements naturels, mais aussi par un certain nombre d'évènements liés aux activités humaines. La détection de ces ondes permet de localiser, voire de caractériser la source, afin de remonter à sa puissance par exemple. Ces ondes sont aussi utilisées en tomographie atmosphérique, pour caractériser les ondes de gravité par exemple. Compte-tenu de la stratification de l'atmosphère imposée par la gravité, ainsi que de la présence de vents, la signature reçue au sol de ces ondes nécessite de prendre en compte de nombreux effets de réfraction sur une altitude de plus de 150 km, de tenir compte de l'absorption visqueuse qui varie fortement en fonction de l'altitude, et de la distorsion du signal associée aux effets non linéaires.   On présentera dans l'exposé quelques ordres de grandeur caractérisant la propagation des infrasons dans l'atmosphère, ainsi que le contexte de ces travaux liés à l'application du traité d'interdiction complète des essais nucléaires (CTBT pour Comprehensive Test Ban Treaty en anglais). L'essentiel de l'exposé sera ensuite consacré à la simulation numérique de ces ondes, et s'appuyant sur des algorithmes numériques qui ont été développés en aéroacoustique. On montrera quelques exemples de simulation, et on soulignera aussi les défis qu'il faudra résoudre, non seulement pour le numérique, mais aussi pour la modélisation d'une atmosphère réaliste par exemple. Ce travail est réalisé dans le cadre du LETMA, structure de recherche du CEA, du CNRS, de l'Ecole Centrale de Lyon et de l'Université Pierre et Marie Curie, et également du LabEx CeLyA, Centre Lyonnais d'Acoustique