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See detailInvariances et ruptures dans le Mercosur
Santander, Sébastian ULg

in Santander, Sébastian (Ed.) Relations internationales et régionalisme. Entre dynamiques internes et projections mondiales (2012)

Cette contribution se penche sur le mode de gouvernance régionale mis en place au travers du Marché commun du sud (Mercosur). En vingt ans d’existence, ce dernier est parvenu à se doter d’une série de ... [more ▼]

Cette contribution se penche sur le mode de gouvernance régionale mis en place au travers du Marché commun du sud (Mercosur). En vingt ans d’existence, ce dernier est parvenu à se doter d’une série de stratégies et d’institutions communes. Il se démarque par sa nature multidimensionnelle et partant se veut une forme de laboratoire des modes de coopération dans des domaines aussi variés que l’économie, le commerce, l’enseignement ou le politique. Toutefois, l’intégration régionale est définie et contrôlée principalement par les États qui la composent et la défense des intérêts nationaux se fait souvent au détriment des engagements communautaires occasionnant d’âpres conflits intrarégionaux. Cette situation révèle les grandes difficultés des instances régionales à résoudre sereinement les différends entre États. Enfin, contrairement aux prédictions, le nationalisme économique et radicalisme politique de cette dernière décennie ne favorisent pas la consolidation de l’intégration et la cohésion régionale. [less ▲]

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See detailInvariances et ruptures dans le régionalisme sud-américain
Santander, Sébastian ULg

in Fédéralisme - Régionalisme (2011), 11, 1

Le présent article se penche sur l'intégration régionale en Amérique du Sud et en particulier sur le Marché commun du sud. Il analyse la dynamique interne de l'intégration et identifient les acteurs ... [more ▼]

Le présent article se penche sur l'intégration régionale en Amérique du Sud et en particulier sur le Marché commun du sud. Il analyse la dynamique interne de l'intégration et identifient les acteurs dominant. Il se penche également sur les stratégies et institutions communes afin de déceler la nature même de l'intégration. [less ▲]

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See detailInvariant bidifferential operators on tensor densities over a contact manifold
Mathonet, Pierre ULg

in Letters in Mathematical Physics (1999), 48(3), 251-261

The spaces of tensor densities over a manifold M are modules over the Lie algebra Vect (M) of vector fields over the manifold. When M is a contact manifold, one can consider the algebra C(M) of vector ... [more ▼]

The spaces of tensor densities over a manifold M are modules over the Lie algebra Vect (M) of vector fields over the manifold. When M is a contact manifold, one can consider the algebra C(M) of vector fields which preserves the contact structure. If the manifold is endowed with a contact projective structure, there is an embedding of the linear symplectic algebra sp (2n+2,R) in C(M). In this Letter, we determine the C(M)- and the sp(2n+2,R)-invariant bidifferential operators on tensor densities. [less ▲]

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See detailInvariant games
Duchêne, Eric; Rigo, Michel ULg

in Theoretical Computer Science (2010), 411

In the context of 2-player removal games, we define the notion of invariant game for which each allowed move is independent of the position it is played from. We present a family of invariant games which ... [more ▼]

In the context of 2-player removal games, we define the notion of invariant game for which each allowed move is independent of the position it is played from. We present a family of invariant games which are variations of Wythoff's game. The set of P-positions of these games are given by a pair of complementary Beatty sequences related to the irrational quadratic number $\alpha_k = (1; \overline{1, k})$. We also provide a recursive characterization of this set. [less ▲]

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See detailInvariant games
Duchêne, Eric; Rigo, Michel ULg

Conference (2009, September)

In the context of 2-player removal games, we define the notion of invariant game for which each allowed move is independent of the position it is played from. We present a family of invariant games which ... [more ▼]

In the context of 2-player removal games, we define the notion of invariant game for which each allowed move is independent of the position it is played from. We present a family of invariant games which are variations of Wythoff's game. The set of P-positions of these games are given by a pair of complementary Beatty sequences related to the irrational quadratic number $\alpha_k = (1; \overline{1, k})$. We also provide a recursive characterization of this set. [less ▲]

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See detailInvariant «electromagnetic» tensors for some subgroups of the conformal group of space-time
Beckers, Jules ULg; Jaminon, Martine ULg

in Journal of Physics : A Mathematical & General (1979), 12

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See detailInvasion and metastatic dissemination in breast cancer: mechanisms
Noël, Agnès ULg; Gilles, Christine ULg; Foidart, Jean-Michel ULg

in Revue Médicale de Liège (2011), 66(5-6), 274-278

Metastases formation is a complex process involving genetic and epigenetic modifications leading to several molecular pathway dysfunctions and alterations in the production and fonction of a panel of ... [more ▼]

Metastases formation is a complex process involving genetic and epigenetic modifications leading to several molecular pathway dysfunctions and alterations in the production and fonction of a panel of molecular mediators. Recent studies have shed light on the importance of multiple interactions occuring between tumor cells and host cells involved in the elaboration of a microenvironment permissive for tumor cell survival and growth. These tumor-host interactions are decisive, not only in the primary tumor, but also in secondary sites colonized by tumor cells. Cancer appears more and more as a sytemic disease in which tumor cell is one of the pawn in the game. System of defense are rapidly overwhelmed and tumor cells hijack host cells to promote their dissemination that likely occurs at earlier stages than initially anticipated. In the present review, we describe the novel concepts of metastases formation based on recent transcriptomic analyses and new insights acquired on the tumor microenvironment in the primary tumor and in secondary foci. [less ▲]

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See detailInvasion and MMP expression profile in desmoid tumours.
Denys, H.; De Wever, O.; Nusgens, Betty ULg et al

in British Journal of Cancer (2004), 90(7), 1443-9

Desmoid tumours are locally invasive soft tissue tumours in which beta-catenin mediated TCF-dependent transcription is activated. The role of soluble factors secreted by the myofibroblastic desmoid tumour ... [more ▼]

Desmoid tumours are locally invasive soft tissue tumours in which beta-catenin mediated TCF-dependent transcription is activated. The role of soluble factors secreted by the myofibroblastic desmoid tumour, which could stimulate tumour invasiveness, was investigated. Using collagen gel invasion assays, the presence of factors stimulating invasion in desmoid conditioned media (CM) could be established. Since matrix metalloproteinases (MMPs) have been implicated in the process of tumoral invasion, the expression levels of the MMP family members were evaluated. Quantitative reverse transcription-PCR was used to determine the expression levels of MMP1, MMP2, MMP3, MMP7, MMP11, MMP12, MMP13, MMP14 and the inhibitors TIMP1, TIMP2 and TIMP3. Besides overexpression of MMP7, a known TCF-dependent target gene, a striking upregulation of the expression levels of MMP1, MMP3, MMP11, MMP12 and MMP13 in desmoid tumours, compared to unaffected fibroblasts from the same patients, was found. Treating the CM of desmoids with a synthetic and a physiologic MMP inhibitor reduced the invasion-stimulating capacity of the desmoid CM by approximately 50%. These results suggest the involvement of soluble factors, released by the desmoid cells, in stimulating invasion and implicate the MMPs as facilitators of invasion. [less ▲]

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See detailInvasion by Fallopia japonica increases topsoil mineral nutrient concentrations
Dassonville, Nicolas; Vanderhoeven, SONIA ULg; Gruber, Wolf et al

in Ecoscience (2007), 14(2), 230-240

Fallopia japonica is one of the most troublesome alien invasive plants across temperate regions, with large negative impacts on plant species diversity. We examined its impacts on topsoil chemistry and ... [more ▼]

Fallopia japonica is one of the most troublesome alien invasive plants across temperate regions, with large negative impacts on plant species diversity. We examined its impacts on topsoil chemistry and nutrient stocks in standing biomass at 6 sites with contrasting resident plant communities in Belgium. Topsoil and biomass were sampled in invaded and closely adjacent uninvaded plots. Standing biomass and mineral nutrient concentrations in soil (ammonium acetate exchangeable cations and P, total C, and N) and plants were determined. Soil under F. japonica generally had higher exchangeable nutrient concentrations (Cu: +45%, K: +34%, Mg: +49%, Mn: +61%, P: +44%, Zn: +75%). Standing biomass was 3- to 13-fold higher depending on site. Despite lower nutrient concentrations in aboveground biomass, invaded stands had 3.2- to 5.4-fold larger nutrient stocks in aboveground biomass compared to the resident vegetation. We conclude that F. japonica enhances nutrient cycling rates and topsoil fertility, probably due to nutrient uplift. The impacts were greatest in sites with low nutrient concentrations in uninvaded plots, suggesting that F. japonica may contribute to soil homogenization in invaded landscapes. [less ▲]

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See detailL'invasion cancéreuse mammaire: le rôle clé des cellules normales des tissus hôtes
Foidart, Jean-Michel ULg; Polette, M.; Birembaut, P. et al

in Bulletin de l'Académie Nationale de Médecine (1994), 178(3), 533-42542-4

Tumor progression is influenced by extracellular matrices and by soluble factors or cytokines locally produced by host tissue cells (fibroblasts, immune cells ...). Such factors may also accumulate in ... [more ▼]

Tumor progression is influenced by extracellular matrices and by soluble factors or cytokines locally produced by host tissue cells (fibroblasts, immune cells ...). Such factors may also accumulate in close association with some extracellular matrix molecules in the tumor. They may also be unmasked during breaking down of extracellular matrices. The most insidious aspect of tumors is their propensity to locally invade normal tissues of the host and to form secondary foci in organs at distant sites from the primary tumor called metastases. During this process, invasive cells come into contact with host tissue cells such as fibroblasts, endothelial cells, macrophages, lymphocytes. These cells are not the passive witnesses of the metastatic cascade but actively participate to the malignant invasion. Through soluble messages (cytokines) and through insoluble molecules of the extracellular matrix, neoplastic and normal cells mutually modulate their activities. Cancer cells regulate the biosynthetic activities of fibroblasts and alter in this way the scaffold of the tumor. Reciprocally, host cells secrete extracellular matrix proteins and cytokines which influence the growth and activities of tumor cells. They also produce at the periphery of tumor cells proteolytic enzymes which promote host tissue destruction and cancerous cells migration. Among these enzymes, matrix metalloproteinases appear to play a key role during invasion and metastasis. Tumors represent thus a complex ecosystem. Tumor cells interact with several components of the extracellular matrix and with host cells (immune cells, fibroblasts, endothelial cells). Such multiple cell-cell and cell-matrix interactions condition angiogenesis, tumor growth, destruction of host tissues, local migration of cancer cells and their metastatic dissemination. It is probable that a precise knowledge of the genes which are selectively activated in tumors under the influence of the host cells or of the tumor cells will allow to define new therapeutic strategies. These treatments will aim not at destroying the metastatic neoplastic cells but at preventing their growth by interfering with their microenvironment. [less ▲]

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See detailInvasion intracellulaire des cellules non-phagocytaires par Staphylococcus aureus
Boulanger, Delphine; Bureau, Fabrice ULg; Lekeux, Pierre ULg

in Annales de Médecine Vétérinaire (2006), 150(1), 27-42

Intracellular invasion of Staphyloccocus aureus in nonphagocytic cells Staphylococcus aureus often causes chronic diseases. It is now believed that recurrence of these infections could be related to the ... [more ▼]

Intracellular invasion of Staphyloccocus aureus in nonphagocytic cells Staphylococcus aureus often causes chronic diseases. It is now believed that recurrence of these infections could be related to the ability of S. aureus to invade and persist within nonphagocytic cells. Adherence to eucaryotic cells is crucial for S. aureus to invade and persist within invasion and depends on interactions between bacterial fibronectin-binding proteins, fibronectin and the host cell fibronectin receptor, integrin alpha(5)beta(1). It is currently established that fibronectin acts as a bridging molecule. Penetration of S. aureus in host cells requires also activation of protein tyrosine kinases that mediate signal transduction and actin polymerization leading to cytoskeletal rearrangements. After internalization, S. aureus either remains in membrane-bound vacuoles or appears free in the cytoplasm. After bacterial proliferation, S. aureus induces host cell apoptosis or persist inside cells as small colony variants, which represent a less virulent subpopulation of S. aureus that grows slower. Although numerous in vitro and in vivo studies have demonstrated the ability of S. aureus to invade nonphagocytic cells, additional experiments have to be realized to understand the relevance of intracellular localization in vivo. [less ▲]

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See detailInvasion of Reconstituted Basement Membrane Matrix Is Not Correlated to the Malignant Metastatic Cell Phenotype
Noël, Agnès ULg; Calle, A.; Emonard, H. et al

in Cancer Research (1991), 51(1), 405-14

Interactions between tumor cells and basement membranes represent a critical step in the progression of neoplasia and in the metastatic process. Reconstituted basement membrane matrix, matrigel, has been ... [more ▼]

Interactions between tumor cells and basement membranes represent a critical step in the progression of neoplasia and in the metastatic process. Reconstituted basement membrane matrix, matrigel, has been recently used with the aim of developing an in vitro assay of tumor cell invasiveness. We have extended these studies by comparing the invasiveness of a large series of normal and malignant epithelial and mesenchymal cells of human and animal origin cultured on matrigel. Normal cells (fibroblasts, glomerular mesangial cells, keratinocytes), human fibrosarcoma cells (HT1080), and reticular sarcoma cells (M5076) clearly established invasive capabilities in the matrix. However, all the other tested cell lines, malignant or virally transformed cells invasive in vivo (MCF7, T47D, SA52, SW613, MO4, A431, BeWo), as well as normal nontransformed cells (MOH22) were incapable of penetration. The morphological features of matrigel invasion by normal fibroblasts and HT1080 cells are described at the light and electron microscope levels. The extent of degradation of a radiolabeled matrigel is minimal and similar in several cell lines reported to be noninvasive or invasive in vivo. Our data suggest that matrigel does not provide a universal model to correlate the invasiveness of cells in vivo and in vitro. [less ▲]

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See detailLes invasions biologiques ... quand Darwin s'en mêle
Vanderhoeven, Sonia ULg; Mahy, Grégory ULg; Vanparys, Valérie et al

in Parcs & Réserves (2009), 64(4), 7-9

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See detailLes invasions biologiques
Vanderhoeven, Sonia ULg; Branquart, Etienne; Grégoire, Jean-Claude et al

in Forêt Wallonne (2007), 89

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See detailInvasions biologiques: un peu de vocabulaire
Jacquemart, Anne-Laure; Vervoort, Arnaud; Lhoir, P. et al

in Silva Belgica (2009)

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See detailInvasive plant species management tests in Southern Belgium
Delbart, Emmanuel ULg; Halford, Mathieu ULg; Pieret, Nora et al

Poster (2009)

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See detailInvasive tricholemmal carcinoma of the nose.
Van Zele, Dirk; Arrese Estrada, Jorge ULg; Heymans, Olivier et al

in Dermatology : International Journal for Clinical & Investigative Dermatology (2002), 204(4), 315-7

Tricholemmal carcinoma is a rare entity. It must be distinguished from the benign proliferating variant of the tricholemmal cyst. We report a case of tricholemmal carcinoma massively invading the nose ... [more ▼]

Tricholemmal carcinoma is a rare entity. It must be distinguished from the benign proliferating variant of the tricholemmal cyst. We report a case of tricholemmal carcinoma massively invading the nose. The neoplasm was excised surgically with a satisfactory outcome. [less ▲]

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