Publications ORBi OA
Bookmark and Share    
Full Text
Peer Reviewed
See detailEquilibrium basal-plane magnetization of superconductive YNi(2)B(2)C: The influence of nonlocal electrodynamics
Thompson, J. R.; Silhanek, Alejandro ULg; Civale, L. et al

in Physical Review. B : Condensed Matter (2001), 64(2),

For a single crystal of YNi(2)B(2)C superconductor, the equilibrium magnetization M in the square basal Plane has been studied experimentally as a function of temperature and magnetic field. While the ... [more ▼]

For a single crystal of YNi(2)B(2)C superconductor, the equilibrium magnetization M in the square basal Plane has been studied experimentally as a function of temperature and magnetic field. While the magnetization M(H) deviates from conventional London predictions, a recent extension of London theory (to include effects of nonlocal electrodynamics) describes the experiments accurately. The resulting superconductive parameters are well behaved. These results are compared with corresponding findings for the case with M perpendicular to the basal plane. [less ▲]

Detailed reference viewed: 5 (1 ULg)
Full Text
See detailEléments pour une politique du volontariat
Defourny, Jacques ULg; Van Buggenhout, Beatrice; D'hondt, Sarah

Book published by Fondation Roi Baudouin (2001)

Detailed reference viewed: 74 (6 ULg)
Full Text
See detailRapport sur le “Workshop on the open archive initiative (OAI) and peer review journals in Europe” - Genève (CERN) 22 au 24 mars 2001
Jérôme, Simone

in Cahiers de la Documentation = Bladen voor Documentatie (2001), (4), 59-63

Detailed reference viewed: 24 (7 ULg)
Full Text
Peer Reviewed
See detailInfluence of nonlocal electrodynamics on the anisotropic vortex pinning in YNi2B2C
Silhanek, Alejandro ULg; Thompson, J. R.; Civale, L. et al

in Physical Review. B : Condensed Matter (2001), 64(1),

We have studied the pinning force density F-p of YNi2B2C superconductors for various field orientations. We observe anisotropies both between the c axis and the basal plane and within the plane that ... [more ▼]

We have studied the pinning force density F-p of YNi2B2C superconductors for various field orientations. We observe anisotropies both between the c axis and the basal plane and within the plane that cannot be explained by the usual mass anisotropy. For magnetic field H parallel toc, the reorientation structural transition in the vortex lattice due to nonlocality, which occurs at a field H(1)similar to1 kOe, manifests itself as a kink in F-p(H). When H perpendicular toc, F-p is much larger and has a quite different H dependence, indicating that other pinning mechanisms are present. In this case the signature of nonlocal effects is the presence of a fourfold periodicity of F-p within the basal plane. [less ▲]

Detailed reference viewed: 6 (1 ULg)
Full Text
See detailThymic T-cell tolerance of neuroendocrine functions: physiology and pathophysiology
Geenen, Vincent ULg; Kecha, Ouafae; Brilot, Fabienne et al

in Halbhuber, Karl-Jürgen; Kinoshita, Yoshihiro (Eds.) Recent Advances in the Immunobiology of the Thymus (2001)

Detailed reference viewed: 27 (2 ULg)
Full Text
See detailImage analysis of carbides in high speed steel rolls and their relationship with the mechanical properties
De Colnet, Laurence; Pirard, Eric ULg; Lecomte-Beckers, Jacqueline ULg et al

in Proceedings of the Euromat Metallographic Conference, Progress in Metallography (2001)

Image analysis is used to describe quantitatively various different natures of carbides in high speed steel rolls. After an etching judiciously selected, the identification and the extraction of the ... [more ▼]

Image analysis is used to describe quantitatively various different natures of carbides in high speed steel rolls. After an etching judiciously selected, the identification and the extraction of the carbide types are based on spectral differences. For every carbide type, three parameters are measure : the size, the spatial distribution and the volume fraction. The size of martensite grain is also measured. [less ▲]

Detailed reference viewed: 75 (7 ULg)
Full Text
See detailLa fouine
Libois, Roland ULg

Learning material (2001)

Detailed reference viewed: 7 (2 ULg)
Full Text
Peer Reviewed
See detailDe Bergson à Merleau-Ponty : pour une anthropologie de la mémoire
Frère, Bruno ULg

in Réseaux : Revue Interdisciplinaire de Philosophie Morale et Politique (2001), 18

On l'a dit et redit, la description de la mémoire par H. Bergson renvoie essentiellement, sinon à la mise en scène d'un mécanisme individuel clos et hermétique, en tout cas à l'aperçu d'une élaboration ... [more ▼]

On l'a dit et redit, la description de la mémoire par H. Bergson renvoie essentiellement, sinon à la mise en scène d'un mécanisme individuel clos et hermétique, en tout cas à l'aperçu d'une élaboration strictement "psychologique" de souvenirs que tout au plus "des mots permettent d'exprimer". Il n'est dès lors pas étonnant qu'à cet égard, Bergson n'ait pas vu "que notre mémoire se ressaisit, au fur et à mesure que nous avançons, (...) sous une forme nouvelle" au sein de cadres sociaux dont l'évolution n'a de cesse de restructurer les souvenirs qui la composent. Selon Halbwachs, "il n'est pas de souvenir qui puisse être dit purement intérieur, c'est-à-dire qui ne puisse se conserver que dans la mémoire individuelle". Ce que le sociologue reproche ainsi au philosophe c'est de ne pas tenir compte du fait qu'un "souvenir reproduit avant tout une perception collective". De ce fait, sa pensée ne permettrait nullement de composer avec la dimension sociale des souvenirs puisqu'ils appartiendraient en propre à divers psychismes hétérogènes qui, du point de vue de ceux qui les observent, se trouvent séparés et isolés "comme par une multitude de cloisons étanches". Ce que nous souhaitons suggérer ici n'est pas, à proprement parler, une nouvelle lecture "exhaustive" de Matière et mémoire qui prétendrait sauver Bergson de la critique sociologique dorénavant consacrée d'Halbwachs. L'ambition de ces lignes sera plutôt d'envisager la manière dont le dernier Merleau-Ponty, s'interrogeant sur l'importance décisive de ce qu'il nomme "le monde culturel", nous autorise à envisager une conception de la mémoire qui réserverait une place réelle à l'altérité tout en se réclamant d'une forme de bergsonisme sensiblement renouvelée et tout en inscrivant ses thèses sur un même terrain philosophique. [less ▲]

Detailed reference viewed: 149 (4 ULg)
Full Text
Peer Reviewed
See detailIrradiation du petit bassin et fonction ano-rectale.
Gervaz, P; COUCKE, Philippe ULg; Gillet, M

in Gastroentérologie Clinique et Biologique (2001), 25

Le traitement adjuvant des cancers du rectum a pour buts de stériliser la maladie résiduelle infra-clinique et d’améliorer le contrôle local. Depuis plus de 20 ans, des milliers de malades ont été inclus ... [more ▼]

Le traitement adjuvant des cancers du rectum a pour buts de stériliser la maladie résiduelle infra-clinique et d’améliorer le contrôle local. Depuis plus de 20 ans, des milliers de malades ont été inclus dans des études randomisées, visant d’abord à mettre en évidence un gain de survie et une réduction des récidives loco-régionales, en relation avec la radiothérapie pré- ou postopératoire, combinée ou non à la chimiothérapie. Les conséquences en termes de qualité de vie de ces traitements ont pourtant été peu étudiées, et la tolérance fonctionnelle du néo-rectum et de l’appareil sphinctérien à la radiothérapie restent mal connues [1]. Les difficultés liées à l’étude des effets de l’irradiation sur les tissus normaux, ainsi que la variabilité inter-individuelle de la réponse à la radiothérapie, s’ajoutent et rendent le sujet plus complexe encore. Les radiothérapeutes adaptent leur technique afin de réduire autant que possible la dose administrée aux tissus normaux avoisinant la tumeur. Dans le cas de l’irradiation du petit bassin, c’est l’intestin grêle qui a longtemps été considéré comme la structure à risque de complications, alors que l’atteinte du sphincter anal était rarement mentionnée [2]. Malgré les répercussions importantes de la dysfonction ano-rectale sur la qualité de vie des malades, l’atteinte du sphincter anal par la radiothérapie est restée un aspect négligé du traitement adjuvant des cancers du petit bassin [3]. Cet article a pour but, à travers une revue de la littérature, de mettre en évidence les effets qualitatifs et quantitatifs de la radiothérapie sur la fonction du sphincter anal, ainsi que de proposer une modification de la technique actuelle d’irradiation des cancers du bas rectum. [less ▲]

Detailed reference viewed: 84 (2 ULg)
Full Text
Peer Reviewed
See detailRadiation therapy alone or combined surgery and radiation therapy in squamous-cell carcinoma of the penis?
Zouhair, A; COUCKE, Philippe ULg; Jeanneret, W et al

in European Journal of Cancer (2001), 37

Abstract To assess the prognostic factors and the outcome in patients with squamous-cell carcinoma of the penis, a retrospective review of 41 consecutive patients with non-metastatic invasive carcinoma of ... [more ▼]

Abstract To assess the prognostic factors and the outcome in patients with squamous-cell carcinoma of the penis, a retrospective review of 41 consecutive patients with non-metastatic invasive carcinoma of the penis, treated between 1962 and 1994, was performed. The median age was 59 years (range: 35±76 years). According to the International Union Against Cancer (UICC) 1997 classi®cation, there were 12 (29%) T1, 24 (59%) T2, 4 (10%) T3 and 1 TX (2%) tumours. The N-classi®cation was distributed as follows: 29 (71%) patients with N0, 8 (20%) with N1, 3 (7%) with N2 and 1 (2%) with N3. Forty-four per cent (n=18) of the patients underwent surgery: partial penectomy with (n=4) or without (n=12) lymph node dissection, or total penectomy with (n=1) or without (n=1) lymph node dissection. 23 patients were treated with radiation therapy alone, and all but 4 of the patients who were operated upon received postoperative radiation therapy (n=14). The median follow-up period was 70 months (range 20±331 months). In a median period of 12 months (range 5±139 months), 63% (n=26) of the patients relapsed (local in 18, locoregional in 2, regional in 3 and distant in 3). Local failure (stump in the operated patients, and the tumour bed in those treated with primary radiation therapy) was observed in 4 out of 16 (25%) patients treated with partial penectomy postoperative radiotherapy versus 14 out of 23 (61%) treated with primary radiotherapy (P=0.06). 15 (83%) out of 18 local failures were successfully salvaged with surgery. In all patients, 5- and 10-year survival rates were 57% (95% con®dence interval (CI), 41±73%) and 38% (95% CI, 21± 55%), respectively. The 5-year local and locoregional rates were 57% (95% CI, 41±73%) and 48% (95% CI, 32±64%), respectively. In patients treated with primary radiotherapy, 5- and 10-year probabilities of surviving with penis preservation were 36% (95% CI, 22±50%) and 18% (95% CI, 2±34%), respectively. In multivariate analyses, survival was signi®cantly in¯uenced by the N-classi®- cation, and surgery was the only independent factor predicting the locoregional control. We conclude that, in patients with squa- mous-cell carcinoma of the penis, local control is better in patients treated with surgery. However, there seems to be no di erence in terms of survival between patients treated by surgery and those treated by primary radiotherapy salvage surgery, with 39% having organ preservation. [less ▲]

Detailed reference viewed: 29 (1 ULg)
Full Text
See detailMicroscopic determination of the nature of MC, M2C, M7C3 (M6C) carbides in high speed steels.
Tchuindjang, Jérôme Tchoufack ULg; Lecomte-Beckers, Jacqueline ULg

in Proceedings of the Annual Meeting of the SBM (société belge de microscopie), Probing the molecular level. (2001)

The present work shows the procedure used to determine the nature of carbides, while using Scanning Electron Microscopy and Energy Dispersive Spectroscopy with X-rays. Then we lay emphasis on optical ... [more ▼]

The present work shows the procedure used to determine the nature of carbides, while using Scanning Electron Microscopy and Energy Dispersive Spectroscopy with X-rays. Then we lay emphasis on optical characterization of carbides. Optical characterization of carbides appear to be the preliminary stage for the general assessment of carbides in HSS microstructure, the final stage of the scheme being the correlation between microstructure parameters (carbides and matrix) and mechanical properties of HSS hot rolling mills rolls. [less ▲]

Detailed reference viewed: 30 (5 ULg)
Full Text
Peer Reviewed
See detailVesical varices in a patient with portal hypertension.
Gaspar, Yves; Detry, Olivier ULg; de Leval, Jean ULg

in New England Journal of Medicine [=NEJM] (2001), 345(20), 1503-4

Detailed reference viewed: 49 (10 ULg)
Full Text
Peer Reviewed
See detailPancreas development in zebrafish: early dispersed appearance of endocrine hormone expressing cells and their convergence to form the definitive islet.
Biemar, F.; Argenton, F.; Schmidtke, R. et al

in Developmental Biology (2001), 230(2), 189-203

To begin to understand pancreas development and the control of endocrine lineage formation in zebrafish, we have examined the expression pattern of several genes shown to act in vertebrate pancreatic ... [more ▼]

To begin to understand pancreas development and the control of endocrine lineage formation in zebrafish, we have examined the expression pattern of several genes shown to act in vertebrate pancreatic development: pdx-1, insulin (W. M. Milewski et al., 1998, Endocrinology 139, 1440-1449), glucagon, somatostatin (F. Argenton et al., 1999, Mech. Dev. 87, 217-221), islet-1 (Korzh et al., 1993, Development 118, 417-425), nkx2.2 (Barth and Wilson, 1995, Development 121, 1755-1768), and pax6.2 (Nornes et al., 1998, Mech. Dev. 77, 185-196). To determine the spatial relationship between the exocrine and the endocrine compartments, we have cloned the zebrafish trypsin gene, a digestive enzyme expressed in differentiated pancreatic exocrine cells. We found expression of all these genes in the developing pancreas throughout organogenesis. Endocrine cells first appear in a scattered fashion in two bilateral rows close to the midline during mid-somitogenesis and converge during late-somitogenesis to form a single islet dorsal to the nascent duodenum. We have examined development of the endocrine lineage in a number of previously described zebrafish mutations. Deletion of chordamesoderm in floating head (Xnot homolog) mutants reduces islet formation to small remnants, but does not delete the pancreas, indicating that notochord is involved in proper pancreas development, but not required for differentiation of pancreatic cell fates. In the absence of knypek gene function, which is involved in convergence movements, the bilateral endocrine primordia do not merge. Presence of trunk paraxial mesoderm also appears to be instrumental for convergence since the bilateral endocrine primordia do not merge in spadetail mutants. We discuss our findings on zebrafish pancreatogenesis in the light of evolution of the pancreas in chordates. [less ▲]

Detailed reference viewed: 21 (0 ULg)
Full Text
Peer Reviewed
See detailPDX:PBX complexes are required for normal proliferation of pancreatic cells during development.
Dutta, S.; Gannon, M.; Peers, Bernard ULg et al

in Proceedings of the National Academy of Sciences of the United States of America (2001), 98(3), 1065-70

The homeobox factor PDX-1 is a key regulator of pancreatic morphogenesis and glucose homeostasis; targeted disruption of the PDX-1 gene leads to pancreatic agenesis in pdx-1(-/-) homozygotes. Pdx-1 ... [more ▼]

The homeobox factor PDX-1 is a key regulator of pancreatic morphogenesis and glucose homeostasis; targeted disruption of the PDX-1 gene leads to pancreatic agenesis in pdx-1(-/-) homozygotes. Pdx-1 heterozygotes develop normally, but they display glucose intolerance in adulthood. Like certain other homeobox proteins, PDX-1 contains a consensus FPWMK motif that promotes heterodimer formation with the ubiquitous homeodomain protein PBX. To evaluate the importance of PDX-1:PBX complexes in pancreatic morphogenesis and glucose homeostasis, we expressed either wild-type or PBX interaction defective PDX-1 transgenes under control of the PDX-1 promoter. Both wild-type and mutant PDX-1 transgenes corrected glucose intolerance in pdx-1 heterozygotes. The wild-type PDX-1 transgene rescued the development of all pancreatic lineages in pdx-1(-/-) animals, and these mice survived to adulthood. In contrast, pancreata from pdx-1(-/-) mice expressing the mutant PDX-1 transgene were hypoplastic, and these mice died within 3 weeks of birth from pancreatic insufficiency. All pancreatic cell types were observed in pdx-1(-/-) mice expressing the mutant PDX-1 transgene; but the islets were smaller, and increased numbers of islet hormone-positive cells were noted within the ductal epithelium. These results indicate that PDX-1:PBX complexes are dispensable for glucose homeostasis and for differentiation of stem cells into ductal, endocrine, and acinar lineages; but they are essential for expansion of these populations during development. [less ▲]

Detailed reference viewed: 21 (2 ULg)
Full Text
Peer Reviewed
See detailReinforcement learning applied to power system oscillations damping
Ernst, Damien ULg

in Proceedings of the 40th Conference on Decision and Control (CDC 2001) (2001)

Detailed reference viewed: 9 (2 ULg)
Full Text
Peer Reviewed
See detailHelioseismic Tests of the New Los Alamos LEDCOP Opacities
Neuforge-Verheecke, C.; Guzik, J. A.; Keady, J. J. et al

in Astrophysical Journal (2001), 561(1), 450-454

We compare the helioseismic properties of two solar models, one calibrated with the OPAL opacities and the other with the recent Los Alamos LEDCOP (Light Element Detailed Configuration Opacity) opacities ... [more ▼]

We compare the helioseismic properties of two solar models, one calibrated with the OPAL opacities and the other with the recent Los Alamos LEDCOP (Light Element Detailed Configuration Opacity) opacities. We show that, in the radiative interior of the Sun, the small differences between the two sets of opacities (up to 6% near the base of the convection zone) lead to noticeable differences in the solar structure (up to 0.3% in sound speed), with the OPAL model being the closest to the helioseismic data. More than half of the difference between the two opacity sets results from the interpolation scheme and from the relatively widely spaced temperature grids used in the tables. The remaining 3% intrinsic difference between the OPAL and the LEDCOP opacities in the radiative interior of the Sun is well within the error bars on the opacity calculations resulting from the uncertainties on the physics. We conclude that both the OPAL and LEDCOP opacities produce solar models in close agreement with helioseismic inferences, but discrepancies still persist at the level of 0.6% between the calculated and inferred sound speed in the radiative interior of the Sun. [less ▲]

Full Text
Peer Reviewed
See detailGene structure and promoter function of a teleost ribosomal protein: a tilapia (Oreochromis mossambicus) L18 gene
Molina, Alfredo; Iyengar, Arati; Marins, Luis F. et al

in Biochimica et Biophysica Acta (2001), 1520(3), 195-202

We have cloned and characterized a tilapia (Oreochromis mossambicus) L18 ribosomal protein gene, including the complete transcribed region and 488 bp of upstream regulatory sequences. We have also ... [more ▼]

We have cloned and characterized a tilapia (Oreochromis mossambicus) L18 ribosomal protein gene, including the complete transcribed region and 488 bp of upstream regulatory sequences. We have also isolated two L18 cDNAs from another tilapia (Oreochromis niloticus) with a few conservative nucleotide differences. Our results suggest the presence of two genes in both species. Reporter constructs were tested for transient expression in CV1 cells and in microinjected zebrafish and tilapia embryos. The tilapia L18 promoter was able to drive expression of the reporter gene in all three experiments, with no apparent preference for a particular tissue. The tilapia L18 promoter is therefore likely to be a powerful tool to drive tissue-independent gene expression in fish. [less ▲]

Detailed reference viewed: 27 (6 ULg)
Full Text
Peer Reviewed
See detailThe ornithine decarboxylase gene is essential for cell survival during early murine development
Pendeville-Samain, Hélène ULg; Carpino, Nick; Marine, Jean-Christophe et al

in Molecular & Cellular Biology (2001), 21(19), 6549-58

Overexpression and inhibitor studies have suggested that the c-Myc target gene for ornithine decarboxylase (ODC), the enzyme which converts ornithine to putrescine, plays an important role in diverse ... [more ▼]

Overexpression and inhibitor studies have suggested that the c-Myc target gene for ornithine decarboxylase (ODC), the enzyme which converts ornithine to putrescine, plays an important role in diverse biological processes, including cell growth, differentiation, transformation, and apoptosis. To explore the physiological function of ODC in mammalian development, we generated mice harboring a disrupted ODC gene. ODC-heterozygous mice were viable, normal, and fertile. Although zygotic ODC is expressed throughout the embryo prior to implantation, loss of ODC did not block normal development to the blastocyst stage. Embryonic day E3.5 ODC-deficient embryos were capable of uterine implantation and induced maternal decidualization yet failed to develop substantially thereafter. Surprisingly, analysis of ODC-deficient blastocysts suggests that loss of ODC does not affect cell growth per se but rather is required for survival of the pluripotent cells of the inner cell mass. Therefore, ODC plays an essential role in murine development, and proper homeostasis of polyamine pools appears to be required for cell survival prior to gastrulation. [less ▲]

Detailed reference viewed: 39 (7 ULg)
Full Text
Peer Reviewed
See detailOn a general decomposition of the error of an approximate stress field in elasticity
Debongnie, Jean-François ULg; Beckers, Pierre ULg

in Computer Assisted Mechanics and Engineering Sciences [=CAMES] (2001), 8

The errors of finite element approximations are analysed in a general frame, which is completely independent from the way through which the approximate solution was obtained. It is found that the error ... [more ▼]

The errors of finite element approximations are analysed in a general frame, which is completely independent from the way through which the approximate solution was obtained. It is found that the error always admits decomposition in two terms, namely the equilibrium error and the compatibility error, which are orthogonal. Each of these admits upper and lower bound that can be computed in a post-processing scheme [less ▲]

Detailed reference viewed: 25 (7 ULg)