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See detailFetal growth restriction: a workshop report
Cetin, I.; Foidart, Jean-Michel ULg; Miozzo, M. et al

in Placenta (2004), 25(8-9), 753-757

Intrauterine growth restriction (IUGR) is associated with significantly increased perinatal morbidity and mortality as well as cardiovascular disease and glucose intolerance in adult life. A number of ... [more ▼]

Intrauterine growth restriction (IUGR) is associated with significantly increased perinatal morbidity and mortality as well as cardiovascular disease and glucose intolerance in adult life. A number of disorders from genetic to metabolic, vascular, coagulative, autoimmune, as well as infectious, can influence fetal growth by damaging the placenta, leading to IUGR as a result of many possible fetal, placental and maternal disorders. Strict definitions of IUGR and of its severity are needed in order to eventually distinguish among different phenotypes, such as gestational age at onset, degree of growth restriction and presence of hypoxia. This report explores and reviews some of the most recent developments in both clinical and basic research on intrauterine growth restriction, by seeking mechanisms that involve genetic factors, utero-placental nutrient availability and vascular growth factors. New exciting findings on the genomic imprinting defects potentially associated with IUGR, and the placental anomalies associated with the decreased nutrient transport are summarized. Moreover, recent data on angiogenic growth factors as well as new information arising from application of gene chip technologies are discussed. (C) 2004 Elsevier Ltd. All rights reserved. [less ▲]

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See detailDiscrimination between Bifidobacterium species from human and animal origin by PCR-restriction fragment length polymorphism
Delcenserie, Véronique ULg; Bechoux, Nathalie ULg; Leonard, Tamara et al

in Journal of Food Protection (2004), 67(6), 1284-1288

Bifidobacteria are normal intestinal flora in humans and animals. The genus Bifidobacterium includes 31 species of significant host specificity. Taking into account their properties, we proposed to use ... [more ▼]

Bifidobacteria are normal intestinal flora in humans and animals. The genus Bifidobacterium includes 31 species of significant host specificity. Taking into account their properties, we proposed to use bifidobacteria as fecal contamination indicators. PCR-restriction fragment length polymorphism on the 16S rDNA gene was used to distinguish the different Bifidobacterium species. Sixty-four strains belonging to 13 different species were differentiated from animal or human origin using one or two restriction enzymes. Moreover, the primers used were specifics of the Bifidobacterium genus. Therefore, this method made it possible to determine both the presence of bifidobacteria in a sample and its origin of contamination. [less ▲]

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See detailFunctional neuroimaging in the vegetative state
Laureys, Steven ULg

in NeuroRehabilitation (2004), 19(4), 335-341

The interest of functional imaging in patients in a vegetative state is twofold. First, the vegetative state continues to represent a major clinical and ethical problem, in terms of diagnosis, prognosis ... [more ▼]

The interest of functional imaging in patients in a vegetative state is twofold. First, the vegetative state continues to represent a major clinical and ethical problem, in terms of diagnosis, prognosis, treatment, everyday management and end-of-life decisions. Second, it offers a lesional approach to the study of human consciousness and adds to the international research effort on identifying the neural correlate of consciousness. Cerebral metabolism has been shown to be massively reduced in the vegetative state. However, recovery of consciousness from vegetative state seems not always associated with substantial changes in global metabolism. Recent PET data indicate that some vegetative patients are unconscious not just because of a global loss of neuronal function, but due to an altered activity in a critical fronto-parietal cortical network and to abolished functional connections within this network and with non-specific thalamic nuclei. Recovery of consciousness was shown to be paralleled by a restoration of this cortico-thalamo-cortical interaction. Despite the metabolic impairment, external stimulation still induces neuronal activation as shown by both auditory and noxious stimuli. However, this activation is limited to primary cortices and dissociated from higher-order associative cortices, thought to be necessary for conscious perception. [less ▲]

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See detailNanostructured polyamide by reactive blending. 2. Transition from nanovesicles to cucumber-like core-shell nanoobjects
Koulic, Christian; Jérôme, Robert ULg

in Progress in Colloid and Polymer Science (2004), 129

Polyamide 12 (PA 12) has been nanostructured by reactive blending with 20 wt% of a symmetric anhydride end-capped polystyrene-b-polyisoprene (PS-b-PIP-anh) The liposome-like nanovesicles which are ... [more ▼]

Polyamide 12 (PA 12) has been nanostructured by reactive blending with 20 wt% of a symmetric anhydride end-capped polystyrene-b-polyisoprene (PS-b-PIP-anh) The liposome-like nanovesicles which are originally formed in the polyamide matrix (PA 12) are converted into cucumber-like core-shell nanoobjects upon increasing the volume fraction of PS by addi-j tion of homo PS of a molecular weight lower than the PS block. The key effect of the molecular weight of homoPS with respect to the PS bloc,k has been emphasized. The same nanoobjects can be prepared by direct blending of PA12 with 20 wt% of an asymmetric reactive PS-b-PIP-anh diblock with the same molecular weight and a higher PS content compared to the symmetric diblock. The interesting point is that the thickness of the rubbery envelope of the core-shell nanoobjects changes with the method used for their preparation at constant PA12/ PS/PIP composition, as result of a change in the molecular weight of the shell forming block. [less ▲]

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See detailInteractions at large distances and spin effects in nucleon-nucleon and nucleon-nuclei scattering
Cudell, Jean-René ULg; Predazzi, E.; Selyugin, Oleg Viktorovich

in Physics of Particles and Nuclei (2004), 35(Suppl. 1), 75-78

The momentum transfer dependence of the slopes of the spin-non-flip and spin-flip amplitudes is analyzed. It is shown that the long tail of the hadronic potential in impact parameter space leads, for ... [more ▼]

The momentum transfer dependence of the slopes of the spin-non-flip and spin-flip amplitudes is analyzed. It is shown that the long tail of the hadronic potential in impact parameter space leads, for hadron-hadron interactions, to a larger value of the slope for the reduced spin-flip amplitude than for the spin-non-flip amplitude. It is also shown that the preliminary measurement of A(N) obtained by the E950 Collaboration confirms such behavior of the hadron spin-flip amplitude. [less ▲]

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See detailInsight and the sleep committee
Maquet, Pierre ULg; Ruby, Perrine

in Nature (2004), 427(6972), 304-305

We all spend about a third of our lives asleep, an essential but seemingly unproductive state. Experimental evidence now emerges to support anecdotal evidence that sleep can stimulate creative thinking.

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See detailIs it safe to design a building structure with simple joints, when they are known to exhibit a semi-rigid behaviour?
Braham, Marc ULg; Jaspart, Jean-Pierre ULg

in Journal of Constructional Steel Research (2004), 60(3-5, MAR-MAY), 713-723

It is shown, by means of computer simulations of the behaviour of a real structure, that it is safe to design a building with the assumption of pinned joints, even when they show a semi-rigid behaviour ... [more ▼]

It is shown, by means of computer simulations of the behaviour of a real structure, that it is safe to design a building with the assumption of pinned joints, even when they show a semi-rigid behaviour. This result is however limited to the cases where the joints show a high ductility, i.e. a capacity of large deformation before the rupture of either the bolts or the welds. Only in few, probably unrealistic cases, this assumption will lead to unsafe results, the lack of safety being however very small, amounting only to a few percent. (C) 2003 Elsevier Ltd. All rights reserved. [less ▲]

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See detailLa composante morphosyntaxique du langage dans les dysphasies : données d'observation francophones
Comblain, Annick ULg

in Enfance (2004), 56(1), 36-45

Les données présentées dans cet article confirment de manière assez forte celles de la littérature. Les performances des sujets dysphasiques (EDP) francophones étudiés sont, d'une part, inférieures à ... [more ▼]

Les données présentées dans cet article confirment de manière assez forte celles de la littérature. Les performances des sujets dysphasiques (EDP) francophones étudiés sont, d'une part, inférieures à celles d'enfants contrôles appariés sur la base de l'âge chronologique (EDL) et, d'autre part, inférieures en production par rapport à la compréhension. Les aspects morphologiques du langage posent des difficultés particulières aux EDP. Les erreurs effectuées par les EDP sont différentes de celles des enfants EDL. Le profil des EDP est tout à fait particulier et ne se superpose que sommairement à celui des EDL. De ce point de vue, nous pouvons parler de déviance. [less ▲]

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See detailLe projet de plate-forme électronique de construction et de gestion qualité de tests standardisés e-C&QCST
Gilles, Jean-Luc ULg; Piette, Sylvie-Anne ULg; Detroz, Pascal ULg et al

in Arzola, S. (Ed.) World education for educational research (WAER) : XIV congreso mundial de ciencias de la educacion : educatores para una nueva cultura : summary of papers abstracts (2004)

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See detailInfluence of morphological characteristics of heterogeneous moraine formations on their mechanical behaviour using image and statistical analysis
Lebourg, Thomas; Riss, Joelle; Pirard, Eric ULg

in Engineering Geology (2004), 73(1-2), 37-50

The study of landslide stability on mountain slopes becomes more difficult when the sliding materials. are heterogeneous. This is a current problem with the old glacial moraines now under study in the ... [more ▼]

The study of landslide stability on mountain slopes becomes more difficult when the sliding materials. are heterogeneous. This is a current problem with the old glacial moraines now under study in the Aspe Valley, Pyrenees. Analysis of slope stability numerical models necessitates accurate data about mechanical and physical properties. Because moraines are very heterogeneous, a large sample is necessary, but, unfortunately, data acquisition costs a lot of time and money. Therefore, we would like to estimate mechanical properties from correlated variables that are easier to acquire (morphological variables using image analysis). Observations in the field and previous mechanical results in the laboratory have shown that differences between the behaviour of moraines seem to be related not only to their three-dimensional structure but also to the morphological and petrographical characteristics of their components. The moraines are classified based on textural characteristics at the sample scales based on the distributions of size and shape of their constitutive elements (blocks, matrix, etc.). Then, we study the statistical distribution of the variables to highlight the most significant variables. Next, we evaluate the results of the mechanical behaviour of the moraines, with the internal angle of friction and the effective cohesion. On seven specific moraines, we established relations between the effective internal angle of friction, the elongation factor and the roughness factor. (C) 2003 Elsevier B.V. All rights reserved. [less ▲]

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See detailThe contribution of 211 particles to the mechanical reinforcement mechanism of 123 superconducting single domains
Mathieu, Jean-Philippe; Cano, I. G.; Koutzarova, T. et al

in Superconductor Science and Technology (2004), 17(1), 169-174

Hardness and fracture toughness of Dy-123 single domains were studied by Vickers in micro-indentation. A significant anisotropy of the mechanical properties was observed. Hardness tests give higher values ... [more ▼]

Hardness and fracture toughness of Dy-123 single domains were studied by Vickers in micro-indentation. A significant anisotropy of the mechanical properties was observed. Hardness tests give higher values when performed in (001) planes rather than in planes parallel to the c-axis. Moreover, the cracks pattern around the indentation follows preferential orientation in planes parallel to the c-axis whereas a classical 'four-cracks' pattern is observed in the (001) planes. It has been possible to show the crucial role played by the 211 particles in the deviating mechanism of cracks and the relevance of the high homogeneity of 211-particle distribution in the material. [less ▲]

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See detailTesting Interactif Multimédia via Internet (TIMI) version 2.0
Gilles, Jean-Luc ULg; Lê, Hung; Pirson, Marc ULg

Software (2004)

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See detailVertical ionization energies of alpha-L-amino acids as a function of their conformation: an ab initio study
Dehareng, Dominique ULg; Dive, Georges ULg

in International Journal of Molecular Sciences (2004), 5(11-12, NOV-DEC), 301-332

Vertical ionization energies (IE) as a function of the conformation are determined at the quantum chemistry level for eighteen alpha-L-amino acids. Geometry optimization of the neutrals are performed ... [more ▼]

Vertical ionization energies (IE) as a function of the conformation are determined at the quantum chemistry level for eighteen alpha-L-amino acids. Geometry optimization of the neutrals are performed within the Density Functional Theory (DFT) framework using the hybrid method B3LYP and the 6-31G**(5d) basis set. Few comparisons are made with wave-function-based ab initio correlated methods like MP2, QCISD or CCSD. For each amino acid, several conformations are considered that lie in the range 10-15 kJ/mol by reference to the more stable one. Their IE are calculated using the Outer-Valence-Green's-Functions (OVGF) method at the neutrals' geometry. Few comparisons are made with MP2 and QCISD IE. It turns out that the OVGF results are satisfactory but an uncertainty relative to the most stable conformer at the B3LYP level persists. Moreover, the value of the IE can largely depend on the conformation due to the fact that the ionized molecular orbitals (MO) can change a lot as a function of the nuclear structure. [less ▲]

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See detailPetrogenesis of the Kabanga-Musongati layered mafic-ultramafic intrusions in Burundi (Kibaran Belt): geochemical, Sr-Nd isotopic constraints and Cr-Ni behaviour
Duchesne, Jean-Clair ULg; Liégeois, Jean-Paul ULg; Deblond, André et al

in Journal of African Earth Sciences (2004), 39

A succession of mafic-ultramafic layered intrusions forms an alignment in the boundary zone between the Kibaran belt and the Tanzania craton. The intrusions represent a continuous series of cumulate rocks ... [more ▼]

A succession of mafic-ultramafic layered intrusions forms an alignment in the boundary zone between the Kibaran belt and the Tanzania craton. The intrusions represent a continuous series of cumulate rocks. For instance, in the Mukanda-Buhoro and Musongati (MBM) contiguous bodies, the series starts with dunite and passes to lherzolite, pyroxenite, norite, gabbronorite and anorthosite on top. Cumulate textures are conspicuous in all rock types and cryptic layering characterises cumulus mineral compositions, thus evidencing fractional crystallization as a major differentiation mechanism. The increase of Cr in the ultramafic members of the series indicates that chromite was not a liquidus mineral in dunite and lherzolite rocks, thus unable to form chromitite layers. The high Ni-content of dunite seems to preclude the existence of conjugate Ni-rich sulphide deposits. The 87Sr/86Sr initial ratio is relatively constant and averages 0.7087, with some values up to 0.712 due to local assimilation. Fine-grained rocks from the MBM area are isotopically (Nd and Sr) similar to the MBM cumulates. Modelling their crystallization produces cumulus mineral compositions similar to those in the Musongati ultramafic rocks, which suggests a broadly picritic parental magma. On the other hand, fine-grained rocks from the Nyabikere area are not related to the Nyabikere cumulates. Nd and Sr isotope ratios show that the MBM magmatism is related to an enriched source, possibly an old subcontinental lithospheric mantle. The Nyabikere dykes, as well as the Waga dykes, come from a depleted mantle source, as do the A-type granitoids occurring in the same boundary zone. Several lines of evidence point to two types of parental magmas, a picritic magma, and a more evolved magma, broadly similar to the Bushveld Main Zone magma. [less ▲]

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See detailExtended formulations for Gomory Corner polyhedra
Köppe, Matthias ULg; Louveaux, Quentin ULg; Weismantel, Robert et al

in Discrete Optimization (2004), 1(2), 141-165

We present several types of extended formulations for integer programs, based on irreducible integer solutions to Gomory’s group relaxations. We present algorithmic schemes based on an iterative ... [more ▼]

We present several types of extended formulations for integer programs, based on irreducible integer solutions to Gomory’s group relaxations. We present algorithmic schemes based on an iterative reformulation technique using these extended formulations. We give computational results for benchmark problems, which illustrate the primal and dual effect of the reformulation. [less ▲]

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See detailThe Vacuum UV Photoabsorption Spectroscopy of the Three membered Ring Systems C3H6, C2H4O and C2H4S and their open Chain Isomers.
Locht, Robert ULg; Leyh, Bernard ULg; Jochims, H.-W. et al

Book published by Berliner Elektronen Speicherring für Elektronen Synchrotron Strahlung m.b.H - on CD-ROM (2004)

The vacuum UV photoabsorption spectrum of C3H6, C2H4O and C2H4S have been measured using synchrotron radiation and are reported.

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See detailDevelopments in finite element simulations of continuous casting
Castagne, Sylvie; Pascon, Frédéric ULg; Blès, Guilhem et al

in Journal de Physique IV (2004), 120

Two complementary approaches of steel continuous casting modelling using the finite element code LAGAMINE have been developed in the M&S Department. We propose here a description of the context in which ... [more ▼]

Two complementary approaches of steel continuous casting modelling using the finite element code LAGAMINE have been developed in the M&S Department. We propose here a description of the context in which the study started, then a description of both macroscopic and mesoscopic approaches. The first one describes the whole continuous casting process, from the free surface in the mould and through the entire machine, including thermal and mechanical behaviour of the steel. The second approach focuses on the prediction of cracks and is developed at the grain scale. Some results are also presented for both models. [less ▲]

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See detailContributions aux algorithmes d'intégration temporelle conservant l'énergie en dynamique non-linéaire des structures
Noels, Ludovic ULg

Doctoral thesis (2004)

Les points fondamentaux de mes recherches consistent en une étude mathématique des algorithmes d'intégration temporelle d'une discrétisation de type éléments-finis. Les algorithmes traditionnels d ... [more ▼]

Les points fondamentaux de mes recherches consistent en une étude mathématique des algorithmes d'intégration temporelle d'une discrétisation de type éléments-finis. Les algorithmes traditionnels d'intégration temporelle (Newmark, famille alpha-généralisée, ...) peuvent introduire numériquement de l'énergie dans les systèmes non-linéaires. De nouveaux algorithmes sont dès lors apparus pour permettre d'éviter cette perte de stabilité. Lors de mes études, ces algorithmes ont été étendus, de manière originale, au traitement de la plasticité à l'aide d'un modèle de type hypo-élastique. Ils ont également été étendus au traitement généralisé, dans le cadre tridimensionnel, de l'interaction de contact. Ensuite la mise en oeuvre d'une méthode permettant de combiner, au cours du temps un algorithme implicite stable, avec un algorithme explicite traditionnel a été envisagée. La stabilité du passage d'une méthode explicite vers une méthode implicite a été démontrée par nos soins. Une définition originale de critères automatiques de choix de basculement entre les méthodes a été proposée. Des exemples numériques complexes ont mis en évidences les bonnes performances des algorithmes développés, tant du point de vue de la précision des résultats - confrontés aux résultats expérimentaux si ces derniers existent -, que du point de vue de la réduction des coûts de calcul lorsque la méthode combinée est utilisée. [less ▲]

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