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See detailPIXE identification of the provenance of ferruginous rocks used by Neanderthals
Mathis, François ULg; Bodu, Pierre; Dubreuil, Olivier ULg et al

in Nuclear Instruments & Methods in Physics Research. Section B, Beam Interactions with Materials and Atoms (in press)

Les Bossats, near Ormesson, France, is a newly discovered late Mousterian open air site dated to around 47,000 years ago by thermoluminescence. The archaeological level, fossilized by loess, revealed a ... [more ▼]

Les Bossats, near Ormesson, France, is a newly discovered late Mousterian open air site dated to around 47,000 years ago by thermoluminescence. The archaeological level, fossilized by loess, revealed a rich industry based on the discoid mode, associated with numerous fragments of red and yellow iron oxide-rich rocks showing clear traces of powder production (abrasion, striation, scraping), which are exceptional remains for this remote period. Archeological material and geological samples from the close environment were studied by PIXE and by petrographical observations made on thin sections. The geological sources were identified by means of PIXE analyses on two IBA facilities: AGLAE (2 MV tandem) at the C2RMF in Paris and the cyclotron of the IPNAS (University of Liège). We paid particular attention to the comparison of results obtained on both installations by using the same set of geological standards and by a fine evaluation of the limit of detection relative to each trace elements of interest for both experimental set ups. The elemental fingerprint of one geological source of iron-rich concretions corresponds clearly with the archaeological collection. At least, this investigation demonstrates that the colouring materials were minutely selected in the close neighbouring of the site by the Neanderthals. [less ▲]

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See detailDocumentário e mal-entendido. Retorno sobre uma primeira filmagem no Brasil
Hamers, Jérémy ULg

in Stols, Eddy; Mascaro, Luciana; Bueno, Clodoaldo (Eds.) Brasil e Bélgica: Cinco Séculos de Conexões e Interação (in press)

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See detailProjectiles and hafting technology
Rots, Veerle ULg

in Iovita, Radu; Sano, Katsuhiro (Eds.) Multidisciplinary Approaches to the Study of Stone Age Weaponry (in press)

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See detailThe soundtrack of RR Lyrae in Omega Cen at high-frequency
Calamida, A.S.; Randall, S.K.; Monelli, M. et al

in Memorie della Società Astronomica Italiana : Journal of the Italian Astronomical Society (in press)

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See detailStone tool hafting in the Middle Palaeolithic as viewed through the microscope
Rots, Veerle ULg

in Marreiros, Juan; Bicho, Nuno (Eds.) Proceedings of the Use-wear conference at Faro, Portugal (in press)

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See detailKeys to the identification of prehension and hafting traces
Rots, Veerle ULg

in Marreiros, Juan; Gibaja, Juan; Bicho, Nuno (Eds.) Use-Wear and Residue Analysis in Archaeology (in press)

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See detailThiamine triphosphate: a ubiquitous molecule in search of a physiological role
Bettendorff, Lucien ULg; Wins, Pierre

in Metabolic Brain Disease (in press)

Thiamine triphosphate (ThTP) was discovered over 60 years ago and it was long thought to be a specifically neuroactive compound. Its presence in most cell types, from bacteria to mammals, would suggest a ... [more ▼]

Thiamine triphosphate (ThTP) was discovered over 60 years ago and it was long thought to be a specifically neuroactive compound. Its presence in most cell types, from bacteria to mammals, would suggest a more general role but this remains undefined. In contrast to thiamine diphosphate (ThDP), ThTP is not a coenzyme. In E. coli cells, ThTP is transiently produced in response to amino acid starvation, while in mammalian cells, it is constitutively produced at a low rate. Though it was long thought that ThTP was synthesized by a ThDP:ATP phosphotransferase, more recent studies indicate that it can be synthesized by two different enzymes: (1) adenylate kinase 1 in the cytosol and (2) FoF1-ATP synthase in brain mitochondria. Both mechanisms are conserved from bacteria to mammals. Thus ThTP synthesis does not seem to require a specific enzyme. In contrast, its hydrolysis is catalyzed, at least in mammalian tissues, by a very specific cytosolic thiamine triphosphatase (ThTPase), controlling the steady-state cellular concentration of ThTP. In some tissues where adenylate kinase activity is high and ThTPase is absent, ThTP accumulates, reaching ≥ 70% of total thiamine, with no obvious physiological consequences. In some animal tissues, ThTP was able to phosphorylate proteins, and activate a high-conductance anion channel in vitro. These observations raise the possibility that ThTP is part of a still uncharacterized cellular signaling pathway. On the other hand, its synthesis by a chemiosmotic mechanism in mitochondria and respiring bacteria might suggest a role in cellular energetics. [less ▲]

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See detailLes animateurs de la vie littéraire en Belgique francophone : de leur rôle interne à leur position de médiateur transnational
Dozo, Björn-Olav ULg

in Blanchard, Nelly; Thomas, Mannaig (Eds.) Des littératures périphériques (in press)

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See detailTowards a more behavioral approach: the contribution of wear studies
Rots, Veerle ULg

in Shott, Michael (Ed.) Works in Stone (in press)

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See detailA generic anisotropic continuum damage model integration scheme adaptable to both ductile damage and biological damage-like situations
Mengoni, Marlène ULg; Ponthot, Jean-Philippe ULg

in International Journal of Plasticity (in press)

This paper aims at presenting a general versatile time integration scheme applicable to anisotropic damage coupled to elastoplasticity, considering any damage rate and isotropic hardening formulations ... [more ▼]

This paper aims at presenting a general versatile time integration scheme applicable to anisotropic damage coupled to elastoplasticity, considering any damage rate and isotropic hardening formulations. For this purpose a staggered time integration scheme in a finite strain framework is presented, together with an analytical consistent tangent operator. The only restrictive hypothesis is to work with an undamaged isotropic material, assumed here to follow a J2 plasticity model. The only anisotropy considered is thus a damage-induced anisotropy. The possibility to couple any damage rate law with the present algorithm is illustrated with a classical ductile damage model for aluminium, and a biological damage-like application. The later proposes an original bone remodelling law coupled to trabecular bone plasticity for the simulation of orthodontic tooth movements. All the developments have been considered in the framework of the implicit non-linear finite element code Metafor (developed at the LTAS/MN2L, University of Liège, Belgium - www.metafor.ltas.ulg.ac.be). [less ▲]

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See detailAn enhanced version of a bone remodelling model based on the continuum damage mechanics theory.
Mengoni, Marlène ULg; Ponthot, Jean-Philippe ULg

in Computer Methods in Biomechanics & Biomedical Engineering (in press)

The purpose of this work is to propose an enhancement of Doblaré and García's internal bone remodelling model based on the continuum damage mechanics theory. In their paper, they stated that the evolution ... [more ▼]

The purpose of this work is to propose an enhancement of Doblaré and García's internal bone remodelling model based on the continuum damage mechanics theory. In their paper, they stated that the evolution of the internal variables of the bone microstructure, and its incidence on the modification of the elastic constitutive parameters, may be formulated following the principles of Continuum Damage Mechanics, although no actual damage was considered. The resorption and apposition criteria (similar to the damage criterion) were expressed in terms of a mechanical stimulus. However, the resorption criterion is lacking a dimensional consistency with the remodelling rate. We here propose an enhancement to this resorption criterion, insuring the dimensional consistency while retaining the physical properties of the original remodelling model. We then analyse the change in the resorption criterion hypersurface in the stress space for a 2D analysis. We finally apply the new formulation to analyse the structural evolution of a 2D femur. This analysis gives results consistent with the original model but with a faster and more stable convergence rate. [less ▲]

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See detailSemiótica de la acción: textualización y notación
Dondero, Maria Giulia ULg

in Tópicos del seminario (2015), 31

Our essay focuses on some methodological issues concerning the semiotic analysis of practice. We will initially retrace the debate about the epistemological relationship between text and action, outlining ... [more ▼]

Our essay focuses on some methodological issues concerning the semiotic analysis of practice. We will initially retrace the debate about the epistemological relationship between text and action, outlining the forms of enunciative praxis through different levels of pertinence analysis. Secondly, we propose the concept of ‘textualization’ as a mediation between text and action: textualizations (photographs, videos, notes) organize and represent practices which are in themselves ephemeral and elusive. Finally, we will consider the textual diagrammatization that we call ‘notation’: this analytical form of mediation between text and practice does not have the same status of in-vivo textualisations, but it works like an ex-post reconstruction which highlights the main gestures and exchanges while performing their grammaticalization. A more general aim of this essay is an enquiry into the legitimate objects of textual semiotics: what are the objects that it can analyze without betraying its principle of immanence, but also without being confined to it and, as a consequence, being unable to analyze practices and respond to topical questions on social issues and on the research in the human sciences? [less ▲]

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See detailQuand la clinique bouscule les concepts
Englebert, Jérôme ULg

Scientific conference (2015, February 11)

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See detailLa démocratie sous expertise. Médias, think tanks et privatisation du débat européen (en préparation, parution début 2015)
Geuens, Geoffrey ULg

Book published by Éditions du Croquant, coll. "Savoir / Agir" (2015)

L’ouvrage questionne la genèse des think tanks eurofédéralistes participant à la fabrication et à la légitimation des politiques d’intégration, avant de s’intéresser à ces autres agents sociaux de ... [more ▼]

L’ouvrage questionne la genèse des think tanks eurofédéralistes participant à la fabrication et à la légitimation des politiques d’intégration, avant de s’intéresser à ces autres agents sociaux de production et de diffusion de la pensée européenne que sont notamment les correspondants bruxellois et éditorialistes de quelques grands médias européens. L’ouvrage montre combien le discours journalistique sur l’Europe et le discours de certains « spécialistes » des questions européennes, qui trouve aussi à s’exprimer dans l’espace médiatique, sont la plupart du temps limités à quelques expressions stéréotypées et argumentaires clichés s’expliquant autant par la position occupée dans le champ du pouvoir par les agents qui s’en font les relais que par les dispositions de ces mêmes agents sociaux à l’égard du « projet européen ». [less ▲]

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See detailEffects of low dose endosulfan exposure on brain neurotransmitter levels in the African clawed frog Xenopus laevis
Preud'Homme, Valérie; Milla, Sylvain; Gillardin, Virginie et al

in Chemosphere (2015), 120(2), 357-364

Understanding the impact of pesticides in amphibians is of growing concern to assess the causes of their decline. Among pesticides, endosulfan belongs to one of the potential sources of danger because of ... [more ▼]

Understanding the impact of pesticides in amphibians is of growing concern to assess the causes of their decline. Among pesticides, endosulfan belongs to one of the potential sources of danger because of its wide use and known effects, particularly neurotoxic, on a variety of organisms. However, the effect of endosulfan was not yet evaluated on amphibians at levels encompassing simultaneously brain neurotransmitters and behavioural endpoints. In this context, tadpoles of the African clawed frog Xenopus laevis were submitted to four treatments during 27 d: one control, one ethanol control, and two low environmental concentrations of endosulfan (0.1 and 1 μg L−1). Endosulfan induced a significant increase of brain serotonin level at both concentrations and a significant increase of brain dopamine and GABA levels at the lower exposure but acetylcholinesterase activity was not modified by the treatment. The gene coding for the GABA transporter 1 was up-regulated in endosulfan contaminated tadpoles while the expression of other genes coding for the neurotransmitter receptors or for the enzymes involved in their metabolic pathways was not significantly modified by endosulfan exposure. Endosulfan also affected foraging, and locomotion in links with the results of the physiological assays, but no effects were seen on growth. These results show that low environmental concentrations of endosulfan can induce adverse responses in X. laevis tadpoles. At a broader perspective, this suggests that more research using and linking multiple markers should be used to understand the complex mode of action of pollutants. [less ▲]

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See detailEffect of stress path on the miniaturizatio size effect for nickel polycrystals
Keller, Clement; Hug, Eric; Duchene, Laurent ULg et al

Conference (2015, January 04)

The mechanical behavior of mettalic materials deeply depends on the size of samples. For specimen dimensions de creasing from a few millimeters to a few micrometers, the general observed trend is a ... [more ▼]

The mechanical behavior of mettalic materials deeply depends on the size of samples. For specimen dimensions de creasing from a few millimeters to a few micrometers, the general observed trend is a softening of the mechanical behavior in tension which affects the stress level and the strain hardening. This effect is triggered by the derease of the number of grains across the thickness ( also called thickness"t" over grain size "d" ratio). The objective of this work is to provide new experimental results in order to analyse the miniaturization size effects for various stress paths without strain gradients across the thickness of the samples. To this aim, experimental tensil tests, large tensile tests and shear tests have been performed on Ni sheets ( 0.5mm) with various grain sizes ensuring different t/d ratios. Results show that the miniaturization softening is affected by triaxiality, the larger is this parameter, the lower is the mechanicval softening. These features seem to be linked to surface effects which are larger for low triaxiality stress paths. Attempts of numerical simulations using strain gradient crystal plasticity model are also performed to confirm the role played by surface effects. [less ▲]

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See detailA new species of Groenlandaspis Heintz, 1932 (Placodermi, Arthrodira) from the Famennian (Late Devonian) of Belgium
Olive, Sébastien ULg; Prestianni, Cyrille; Dupret, Vincent

in Journal of Vertebrate Paleontology (2015), 35(5),

A new species of the phlyctaeniid arthrodire genus Groenlandaspis from the upper Famennian of Belgium is described. The remains of Groenlandaspis potyi sp. nov. consist of dissociated thoracic armor ... [more ▼]

A new species of the phlyctaeniid arthrodire genus Groenlandaspis from the upper Famennian of Belgium is described. The remains of Groenlandaspis potyi sp. nov. consist of dissociated thoracic armor elements, but the specimen designed to be the holotype displays the median dorsal, anterior and posterior dorsolateral plates in connection. Though incomplete, the new species is characterized by an equilateral triangle-shaped median dorsal plate, a protruding posterodorsal apron of the posterior dorsolateral plate behind the overlap area for the median dorsal plate, and an overall lack of ornamentation. Groenlandaspis potyi sp. nov. constitutes the second occurrence of a Groenlandaspis species in continental Europe after the description of Groenlandaspis thorezi from upper Famennian quarries of Belgium. Another probable new species of Groenlandaspis is also described, though of unknown locality and horizon; it can however be deduced from the upper Famennian of Belgium without more precision. Together with some unpublished material of groenlandaspidids from the Famennian tetrapod-bearing locality of Strud, this material highlights the richness of the Groenlandaspididae diversity in Belgium. The discovery of Groenlandaspis potyi sp. nov. in Belgium reinforces the Famennian global distribution of this widespread genus during this period. Also, since those organisms have possibly been considered as non-marine indicators, this material is another argument pleading for close relationships between Euramerica and Gondwana around the Frasnian-Famennian boundary. [less ▲]

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See detailElsvier, Computers in Industry, Special Issue on Natural Language Processing and Text Analytics in Industry
Ittoo, Ashwin ULg; Bosh, v.d., Antal; Nguyen, Le Minh

Book published by Elsevier (2015)

Detailed reference viewed: 23 (5 ULg)