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See detailThe Discoid techno-complex (MIS 3) at Ormesson and across the Paris sedimentary Basin: consistency and flexibility of a singular technical choice with relation to the lithological context
Leroyer, Mathieu; Bodu, Pierre; Salomon, Hélène ULg et al

Conference (2014)

During the last decade new excavations and reexaminations of old collection have refreshed our vision of the end of the Middle Palaeolithic. Among those advances, the identification of a "Discoid techno ... [more ▼]

During the last decade new excavations and reexaminations of old collection have refreshed our vision of the end of the Middle Palaeolithic. Among those advances, the identification of a "Discoid techno-complex” during the MIS 3 Interpleniglacial event, which differs deeply with other sub-contemporaneous technological practices, reinforce the idea that this period witnessed distinct stone knapping traditions. However, such claims must be established within different geographical and lithological context, in order to invalidate more parsimonious explanations of technical variability. The newly excavated open-air camp site in Ormesson has provided multiple well preserved archaeological layers. The older is dominated by Discoid flaking method and dates to the MIS 3. These occupations took place in a geographical context where flint is not present in situ but was easily available from different sources within the “daily range” of the site. For instance Gravettian and Châtelperronian have preferentially used Campanian flint available 5 km from the site along the Loing River. So far the lithic chaînes opératoires in the Discoid Mousterian layer are characterised by a more limited technical involvement both in term of flint procurement (lower flint quality) and knapping gesture. At the same time, the Neandertal occupants invested considerable effort to extract, import and select the raw ochreous material, whose numerous remains have been found associated with stone tool in the Layer 4. The fact that they did not take advantage of the same trips not only for ochre but also for better flint supply seems problematic. Another characteristic of Ormesson Discoid assemblage is, for the moment, the scarcity of retouched implements, in particular of notches and denticulates which frequently characterize the techno-complex in South-western France. Are such characteristics representative of a state of progress in the excavations? Are they relevant of local techno-economic tactics, or subtle cultural specificities? In addition to ongoing excavation progress at Ormesson, a complementary way to solve these questions will be to enlarge the scope of the analysis to the whole Paris Basin. In that space, Discoidal assemblages have been now studied from very contrasting geographical and lithological contexts. For instance, Arcy-sur-Cure cave sites, on one side, Beauvais and Mennecy open-air sites on the other side, are respectively located at the very margin and near the center of the limestone dominated basin. As a consequence we observe great variations of flint availability from these different contexts. The preliminary comparison of the datas available confirms the existence of similar knapping methods and goals during a limited period, broadly centered on the MIS 3. But it also suggests some intrinsic adaptability of the Discoid typo-technological system to raw material nature and availability. When replaced in that perspective, the different characteristics of stone tool production currently recognized at Ormesson don’t appear, so far, to underline any cultural peculiarity on that site and fit with a coherent vision of the Discoid techno-complex also in Northern part of France. In return, the singular preservation of Ochre at Ormesson, offers a punctual opportunity to integrate what we increasingly know about these knapping habits with more obscure but anyway complementary aspects of a cultural system. [less ▲]

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See detailDiscongruence of Mhc and cytochrome b phylogeographical patterns in Myodes glareolus (Rodentia: Cricetidae)
Malé, P.-J. G.; Martin, J.-F.; Galan, M. et al

in Biological Journal of the Linnean Society (2012), 105(4), 881-899

In the present study, a phylogeographical approach was developed to analyse the influence of selection and history on a major histocompatibility complex (Mhc) class II gene polymorphism in European bank ... [more ▼]

In the present study, a phylogeographical approach was developed to analyse the influence of selection and history on a major histocompatibility complex (Mhc) class II gene polymorphism in European bank vole (Myodes glareolus) populations. We focused on exon 2 of the Dqa gene because it is highly variable in a large array of species and appears to evolve under pathogen-mediated selection in several rodent species. Using single-strand conformation polymorphism analysis and sequencing techniques, 17 Dqa-exon2 alleles, belonging to at least two different copies of Dqa gene, were detected over the distribution range of M.glareolus. Evidence of selection was found using molecular and population analyses. At the molecular level, we detected 13 codons evolving under positive selection pressures, most of them corresponding to regions coding for putative antigen binding sites of the protein. At the European level, we compared patterns of population structure for the Dqa-exon2 and cytochrome b (cyt b) gene. We did not detect any spatial genetic structure among M.glareolus populations for the Dqa-exon2. These results strongly differed from those obtained using the cyt b gene, which indicated a recent phylogeographical history closely linked to the last glacial events. Seven mitochondrial lineages have yet been described, which correspond to major glacial refugia. Altogether, our results revealed clear evidence of balancing selection acting on Dqa-exon2 and maintaining polymorphism over large geographical areas despite M.glareolus history. It is thus likely that Mhc phylogeographical variability could have been shaped by local adaptation to pathogens. © 2012 The Linnean Society of London. [less ▲]

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See detailDiscontinuité des liens et souffrance psychique : quelles stratégies adaptatives en situation de précarité sociale ?
Glowacz, Fabienne ULg; Spitz, Jacqueline

Poster (2014, December)

Dans un contexte social en mutation prônant l’autonomie de l’individu, le passage à l’âge adulte pour les jeunes en situation de vulnérabilité économique sociale et relationnelle se révèle un véritable ... [more ▼]

Dans un contexte social en mutation prônant l’autonomie de l’individu, le passage à l’âge adulte pour les jeunes en situation de vulnérabilité économique sociale et relationnelle se révèle un véritable défi. L’objectif de l’étude est de comprendre les ressources et les conduites adaptatives de ces jeunes leur permettant de faire face à la souffrance psychique que génère la discontinuité des liens, et d’éviter la désaffiliation sociale et l’errance. Cette recherche clinique de terrain s’inscrit dans une approche ethno-psychologique par sa méthode. Elle s’appuie sur les récits de 6 jeunes adultes âgés entre 19 et 25 ans rencontrés dans le cadre d’un hébergement temporaire en maison d’accueil. Chaque récit est séquencé et analysé selon plusieurs niveaux : les indicateurs sociologiques du passage à l’âge adulte, les modes de relations des individus au niveau familial et social, les indicateurs de précarité. Le parcours de ces jeunes adultes en situation de précarité sociale, cumulant vulnérabilité relationnelle et vulnérabilité économique, les amène à développer des conduites qui leur permettent à la fois de préserver le lien avec autrui, de s’adapter à l’environnement et de préserver une maîtrise d’une affiliation anxiogène. Leur vécu expérientiel de rupture et de perte continue à s’actualiser dans une nécessaire oscillation entre rapprochement et distanciation, en résonnance avec leur style d’attachement primaire. Conclusion « Etablir le lien sur un mode discontinu » apparait comme un mode d’adaptation à l’environnement à la fois protecteur de leur intégrité psychique et fragilisant leur socialisation. [less ▲]

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See detailDiscontinuity in Jupiter's main auroral oval
Radioti, Aikaterini ULg; Gérard, Jean-Claude ULg; Grodent, Denis ULg et al

Conference (2007, April 15)

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See detailDiscontinuity in Jupiter's main auroral oval
Radioti, Aikaterini ULg; Gérard, Jean-Claude ULg; Grodent, Denis ULg et al

in Journal of Geophysical Research. Space Physics (2008), 113

On the basis of a series of FUV Hubble Space Telescope images obtained between 1997 and 2007 it is shown that there is a segment of the main auroral oval where the emission drops significantly from a few ... [more ▼]

On the basis of a series of FUV Hubble Space Telescope images obtained between 1997 and 2007 it is shown that there is a segment of the main auroral oval where the emission drops significantly from a few hundreds to a few tens of kiloRayleigh, forming a discontinuity in the oval. It is shown that the discontinuity is present in both hemispheres and confined in magnetic local time. Its equatorial source is located in the prenoon and early noon sector. The main auroral oval is associated with the ionosphere-magnetosphere coupling current system which is related to the breakdown of corotation in the middle magnetosphere. Necessary for the electron precipitation in the ionosphere and the formation of the main auroral oval is the presence of upward field-aligned currents, carried by downward moving electrons. Field-aligned currents inferred by Pioneer, Voyager and Galileo in situ observations in the near equatorial plane showed evidence of reduced or/and downward field-aligned currents in the prenoon and early afternoon sector, the location of the equatorial source of the discontinuity. Additionally, we estimate the precipitation energy flux in the ionosphere, for a typical reduced upward field-aligned current value at that region, which is found to be within the range of the observed brightness of the discontinuity. Field aligned current distributions in the ionosphere based on magnetohydrodynamic simulations of the interaction between the solar wind and the magnetosphere have predicted a region of downward currents implying a discontinuity at the main auroral oval emission, in very good agreement with the HST observations presented in this work. [less ▲]

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See detailA Discontinuous Galerkin Formulation of Kirchhoff-Love Shells: From Linear Elasticity to Finite Deformations
Noels, Ludovic ULg; Radovitzky, Raul

Conference (2008, June)

Spatially-discontinuous Galerkin methods constitute a generalization of weak formulations, which allow for discontinuities of the problem unknowns in its domain interior [1]. When considering problems ... [more ▼]

Spatially-discontinuous Galerkin methods constitute a generalization of weak formulations, which allow for discontinuities of the problem unknowns in its domain interior [1]. When considering problems involving high-order derivatives, discontinuous Galerkin methods can also be seen as a means of enforcing higher-order continuity requirements in a weak manner [2,3]. Recently, the authors [4] have proposed a DG formulation for Kirchhoff-Love shell theory for which both the membrane and the bending response of the shell are considered. The proposed one-field formulation takes advantage of the weak enforcement in such a way that the displacements are the only discrete unknowns, while the C1 continuity is enforced weakly. The consistency, stability and rate of convergence of the numerical method are demonstrated for the case of a linear elastic material. In this work, this method is extended to shell problems involving finite displacements and finite deformations. [less ▲]

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See detailA discontinuous Galerkin formulation of non-linear Kirchhoff–Love shells
Noels, Ludovic ULg

in International Journal for Numerical Methods in Engineering (2009), 78(3), 296-323

Discontinuous Galerkin (DG) methods provide a means of weakly enforcing the continuity of the unknown-field derivatives and have particular appeal in problems involving high-order derivatives. This ... [more ▼]

Discontinuous Galerkin (DG) methods provide a means of weakly enforcing the continuity of the unknown-field derivatives and have particular appeal in problems involving high-order derivatives. This feature has previously been successfully exploited (Comput. Methods Appl. Mech. Eng. 2008; 197:2901-2929) to develop a formulation of linear Kirchhoff-Love shells considering only the membrane and bending responses. In this proposed one-field method - the displacements are the only unknowns, while the displacement field is continuous, the continuity in the displacement derivative between two elements is weakly enforced by recourse to a DG formulation. It is the purpose of the present paper to extend this formulation to finite deformations and non-linear elastic behaviors. While the initial linear formulation was relying on the direct linear computation of the effective membrane stress and effective bending couple-stress from the displacement field at the mid-surface of the shell, the non-linear formulation considered implies the evaluation of the general stress tensor across the shell thickness, leading to a reformulation of the internal forces of the shell. Nevertheless, since the interface terms resulting from the discontinuous Galerkin method involve only the resultant couple-stress at the edges of the shells, the extension to non-linear deformations is straightforward. [less ▲]

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See detailDiscontinuous Galerkin Method for Computing Induced Fields in Superconducting Materials
Kameni, A.; Lambrechts, J.; Remacle, J.-F. et al

in IEEE Transactions on Magnetics (2012), 48(2), 591-594

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See detailDiscontinuous Galerkin Method for Computing Induced Fields in Superconducting Materials"
Kameni, A.; Lambrechts, J.-F.; Remacle, J.-F. et al

in Proceedings of the 18th Conference on the Computation of Electromagnetic Fields (COMPUMAG 2011) (2011, July)

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See detailDiscontinuous Galerkin method for computing vectorials fields in superconductors
Kameni, A.; Boukebeur, F.; Bouillault, F. et al

in Proceedings of the 5th international conference on Advanced COmputational Methods in ENgineering (ACOMEN 2011) (2011, November)

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See detailDiscordance between bovine leukemia virus tax immortalization in vitro and oncogenicity in vivo.
Twizere, Jean-Claude ULg; Kerkhofs, Pierre; Burny, Arsène et al

in Journal of Virology (2000), 74(21), 9895-902

Bovine leukemia virus (BLV) Tax protein, a transcriptional activator of viral expression, is essential for viral replication in vivo. Tax is believed to be involved in leukemogenesis because of its second ... [more ▼]

Bovine leukemia virus (BLV) Tax protein, a transcriptional activator of viral expression, is essential for viral replication in vivo. Tax is believed to be involved in leukemogenesis because of its second function, immortalization of primary cells in vitro. These activities of Tax can be dissociated on the basis of point mutations within specific regions of the protein. For example, mutation of the phosphorylation sites at serines 106 and 293 abrogates immortalization potential in vitro but maintains transcriptional activity. This type of mutant is thus particularly useful for unraveling the role of Tax immortalization activity during leukemogenesis independently of viral replication. In this report, we describe the biological properties of BLV recombinant proviruses mutated in the Tax phosphorylation sites (BLVTax106+293). Titration of the proviral loads by semiquantitative PCR revealed that the BLV mutants propagated at wild-type levels in vivo. Furthermore, two animals (sheep 480 and 296) infected with BLVTax106+293 developed leukemia or lymphosarcoma after 16 and 36 months, respectively. These periods of time are within the normal range of latencies preceding the onset of pathogenesis induced by wild-type viruses. The phenotype of the mutant-infected cells was characteristic of a B lymphocyte (immunoglobulin M positive) expressing CD11b and CD5 (except at the final stage for the latter marker), a pattern that is typical of wild-type virus-infected target cells. Interestingly, the transformed B lymphocytes from sheep 480 also coexpressed the CD8 marker, a phenotype rarely observed in tumor biopsies from chronic lymphocytic leukemia patients. Finally, direct sequencing of the tax gene demonstrated that the leukemic cells did not harbor revertant proviruses. We conclude that viruses expressing a Tax mutant unable to transform primary cells in culture are still pathogenic in the sheep animal model. Our data thus provide a clear example of the discordant conclusions that can be drawn from in vitro immortalization assays and in vivo experiments. These observations could be of interest for other systems, such as the related human T-cell leukemia virus type 1, which currently lack animal models allowing the study of the leukemogenic process. [less ▲]

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See detailDiscordant monozygotic twins for macrocephaly-capillary malformation
Lederer, Damien; Battisti, Oreste ULg; Rack, Katrine et al

in American Journal of Medical Genetics (2012)

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See detailIl discorso di Francesco Guicciardini a Leone X e Francesco I, in vista dell'incontro di Bologna (11 dicembre 1515). Edizione e commento
Moreno, Paola ULg

in Giornale Storico della Letteratura Italiana (2011), CXXVIII(624), 509-522

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See detailDiscours 1919
Hubert, Eugène ULg

Speech/Talk (1919)

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See detailDiscours à l'occasion de la réouverture solennelle des cours
Gloesener, Michel ULg

Speech/Talk (1847)

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See detailLes discours critiques dans les sciences de la gestion
Robert, Jocelyne ULg

Diverse speeche and writing (2013)

La présentation des discours critiques dans les sciences de la gestion nous permettra de souligner l’existence de différents courants au sein des sciences de gestion. Les discours critiques dénonçant les ... [more ▼]

La présentation des discours critiques dans les sciences de la gestion nous permettra de souligner l’existence de différents courants au sein des sciences de gestion. Les discours critiques dénonçant les théories et pratiques de management management se présentent sous forme d’ouvrages scientifiques ou de manuels, d’essais. Ils sont produits par des académiques et des consultants. L’existence de ces discours peut être expliquée par les difficultés que rencontrent les systèmes sociaux et économiques, par les approches de certaines disciplines (sociologie, psychologie, philosophie notamment), par les discours d’acteurs confrontés à des expériences remettant en question le crédo officiel. Ces discours permettent de mettre en évidence les faiblesses du modèle dominant et jettent les bases d’une nouvelle discipline davantage favorable à la controverse et aux oppositions. [less ▲]

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