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See detailIdentification of cyclooxygenase-2 as a major actor of the transcriptomic adaptation of endothelial and tumor cells to cyclic hypoxia: effect on angiogenesis and metastases.
Daneau; Boidot; MARTINIVE, Philippe ULg et al

in Clinical Cancer Research : An Official Journal of the American Association for Cancer Research (2010), 16(2), 410-419

Purpose: Cyclic hypoxia in tumors originates from heterogeneities in RBC flux and influences not only tumor cells but also endothelial cells lining tumor blood vessels. Whether pO2 fluctuations ... [more ▼]

Purpose: Cyclic hypoxia in tumors originates from heterogeneities in RBC flux and influences not only tumor cells but also endothelial cells lining tumor blood vessels. Whether pO2 fluctuations, particularly transient reoxygenation periods, alter the well-known hypoxia-inducible factor (HIF)–dependent gene program is largely unknown. Experimental Design: We compared the transcriptomic profiles of endothelial and tumor cells exposed to cyclic hypoxia versus continuous hypoxia to uncover a possible differential effect on angiogenesis and metastases. Results: Microarray analyses identified early genes that were selectively induced by cyclic hypoxia in endothelial cells. Among them, we focused on PTGS2 because the observed increase in mRNA expression led to a significant increase in the expression and activity of cyclooxygenase-2 (COX-2; the protein product of PTGS2). HIF-1α was shown to be stabilized by cyclic hypoxia (despite reoxygenation periods) and to favor COX-2 induction as validated by the use of echinomycin and HIF-1α targeting small interfering RNA. Using a specific COX-2 inhibitor and a dedicated COX-2 targeting small interfering RNA, we documented that COX-2 accounted for the higher endothelial cell survival and angiogenic potential conferred by cyclic hypoxia. Cyclic hypoxia also led to a preferential COX-2 induction in tumor cells and, contrary to continuous hypoxia, fostered a higher metastatic take of prechallenged tumor cells. Conclusions: Our study documents that PTGS2/COX-2 is part of a cyclic hypoxia gene signature and largely accounts for the unique phenotype of endothelial and tumor cells exposed to fluctuations in pO2, thereby offering new perspectives for the clustering of tumors expressing COX-2 together with other cyclic hypoxia-responsive genes. Clin Cancer Res; 16(2); 410–9 [less ▲]

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See detailIdentification Of Cystosolic Mg2+-Dependent Soluble Inorganic Pyrophosphatases In Potato And Phylogenetic Analysis
Rojas-Beltran, Ja.; Dubois, Françoise ULg; Mortiaux, F. et al

in Plant Molecular Biology (1999), 39(3),

Detailed reference viewed: 24 (5 ULg)
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See detailIdentification of cytotoxic factors in media conditioned by mouse B16 melanoma cells
Siwek, Brigitte; Gillet, Marie-Claire ULg; Sabbioni, Enrico et al

in Anticancer Research (1990), 10(5B), 1390

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See detailIdentification of Different Target Glycoproteins for Bovine Herpes Virus Type 1-Specific Cytotoxic T Lymphocytes Depending on the Method of in Vitro Stimulation
Denis, M.; Slaoui, M.; Keil, G. et al

in Immunology (1993), 78(1), 7-13

Vaccinia virus recombinants expressing the three major bovine herpes virus-1 (BHV-1) glycoproteins gI, gIII and gIV were used to identify the major target antigens for BHV-1-specific CTL isolated from ... [more ▼]

Vaccinia virus recombinants expressing the three major bovine herpes virus-1 (BHV-1) glycoproteins gI, gIII and gIV were used to identify the major target antigens for BHV-1-specific CTL isolated from immune cattle. Peripheral blood mononuclear cells (PBMC) expanded in vitro in the presence of interleukin-2 (IL-2) and lysed both gIII- and gIV-infected target cells. Secondary in vitro stimulation of PBMC was also performed in the presence of either fixed BHV-1-infected autologous fibroblasts or ultraviolet (UV)-inactivated virus. Both methods of antigen presentation allowed the proliferation of BHV-1-specific CTL but the target glycoprotein for these CTL differed depending on the method of stimulation. Vaccinia-gIV-infected targets were lysed predominantly when PBMC were stimulated by fixed infected fibroblasts, whilst PBMC stimulated by UV-inactivated virus lysed mostly vaccinia-gIII-infected targets. This observation could be explained by a different processing pathway of BHV-1 antigens in each cell type involved. [less ▲]

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See detailIdentification of differential item functioning by logistic regression: application to intellectual disability data
Magis, David ULg; Facon, Bruno

Conference (2010, October 14)

The purpose of this talk is to briefly present the logistic regression procedure to identify differential itm functioning (DIF) in psychometrics, and to illustrate the method on a practical data set about ... [more ▼]

The purpose of this talk is to briefly present the logistic regression procedure to identify differential itm functioning (DIF) in psychometrics, and to illustrate the method on a practical data set about intellectual disability. DIF is an important research fi eld and many statistical methods have been developed in this framework. Logistic regression has the asset of not being based on item response models, and it can detect both uniform and nonuniform DIF. In addition, it can be applied to the comparison of more than two groups. This method is illustrated by comparing two groups of French pupils, one group of normal ability students and one group with intellectually disabled students. Raven's Colored Progressive Matrices test is assigned and DIF is investigated between the two groups. It is concluded that none of the items can be flagged as functioning differently. [less ▲]

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See detailIdentification of differential item functioning in multiple-group settings: A multivariate outlier detection approach
Magis, David ULg; De Boeck, Paul

in Multivariate Behavioral Research (2011), 46

This paper focuses on the identification of differential item functioning (DIF) when more than two groups of examinees are considered. We propose to consider items as elements of a multivariate space ... [more ▼]

This paper focuses on the identification of differential item functioning (DIF) when more than two groups of examinees are considered. We propose to consider items as elements of a multivariate space, where DIF items are outlying elements. Following this approach, the situation of multiple groups is a quite natural case. A robust statistics technique is proposed to identify DIF items as outliers in the multivariate space. For low dimensionalities, up to two three groups, also a simple graphical tool is derived. We illustrate our approach with a re-analysis of data from Kim, Cohen, and Park (1995) on using calculators for a mathematics test. [less ▲]

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See detailIdentification of differential pattern of protein expression in canine osteoarthritis serum after anterior cruciate ligament transection: a proteomic analysis.
Gharbi, Myriam; Sanchez, Christelle ULg; Mazzucchelli, Gabriel ULg et al

in Veterinary journal (London, England : 1997) (2013), 197(3), 848-53

Osteoarthritis (OA) management remains a great challenge and there is considerable effort to understand its pathophysiology and to identify new therapeutic targets and biomarkers. Canine OA surgically ... [more ▼]

Osteoarthritis (OA) management remains a great challenge and there is considerable effort to understand its pathophysiology and to identify new therapeutic targets and biomarkers. Canine OA surgically induced by the transection of the anterior cruciate ligament (ACLT) is a widely used and relevant model. This study reports a proteome mapping of dog serum and an analysis of the differentially expressed proteins between before and after ACLT. In the first part of the study, 261 picked protein spots were identified from preparative 2D gels and 71 different proteins were identified among the 261 spots present on the reference map. Canine serum proteome mapping reveals the presence of proteins of interest, such as fetuin B, complement C3 and C1s and pregnancy zone protein. The comparison between serum from dogs before and after ACLT reveals the differential expression of several proteins that could play a key role in the pathogenesis of OA. A number of proteins, such as fetuin B and complement C3, were increased in dog OA serum whereas others, such as hyaluronan binding protein 2, inter-alpha-trypsin inhibitor H4 (ITIH4), complement C1s and C4 and haptoglobin were decreased. Some of these proteins could be candidate biomarkers for diagnosis, prognosis and treatment evaluation. The results of the study also reinforced the similarities between dog experimental OA and human cases of OA. [less ▲]

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See detailIdentification of differentially expressed genes in the zebrafish hypothalamic-pituitary axis.
Toro, Sabrina; Wegner, Jeremy; Muller, Marc ULg et al

in Gene Expression Patterns (2009), 9(4), 200-8

The vertebrate hypothalamic-pituitary axis (HP) is the main link between the central nervous system and endocrine system. Although several signal pathways and regulatory genes have been implicated in ... [more ▼]

The vertebrate hypothalamic-pituitary axis (HP) is the main link between the central nervous system and endocrine system. Although several signal pathways and regulatory genes have been implicated in adenohypophysis ontogenesis, little is known about hypothalamic-neurohypophysial development or when the HP matures and becomes functional. To identify markers of the HP, we constructed subtractive cDNA libraries between adult zebrafish hypothalamus and pituitary. We identified previously published genes, ESTs and novel zebrafish genes, some of which were predicted by genomic database analysis. We also analyzed expression patterns of these genes and found that several are expressed in the embryonic and larval hypothalamus, neurohypophysis, and/or adenohypophysis. Expression at these stages makes these genes useful markers to study HP maturation and function. [less ▲]

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See detailIdentification Of Distinct Potyviruses In Mixedly-Infected Sweet-Potato By The Polymerase Chain-Reaction With Degenerate Primers
Colinet, D.; Kummert, J.; Lepoivre, Philippe ULg et al

in Phytopathology (1994), 84(1),

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See detailIdentification of eae genes in rabbit attaching and effacing enteropathogenic Escherichia coli (EPEC)
Pohl, P.; Peeters, J. E.; Jacquemin, E. R. et al

in Infection and Immunity (1993), 61

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See detailIdentification of elastic orthotropic material parameters by inverse modeling using ESPI
Lecompte, D.; Sol, H.; Vantomme, J. et al

in Proceedings of the 2005 SEM Annual Conference & Exposition on Experimental and Applied Mechanics (2005)

Parameter identification methods, which integrate optimization techniques and numerical methods such as the finite element method (FEM), offer an alternative tool for material characterisation. The most ... [more ▼]

Parameter identification methods, which integrate optimization techniques and numerical methods such as the finite element method (FEM), offer an alternative tool for material characterisation. The most common approach is to determine the optimal estimates of the model parameters by minimizing a selected measure-of-fit between the responses of the system and the model. The possibility is studied of retrieving the four independent elastic engineering constants for an orthotropic medium, based on the measurement of a heterogeneous displacement field. In the present case a tensile test is performed on a perforated specimen. The responses of the system, i.e. the surface displacements are measured with an Electronic Speckle Pattern Interferometer. Strains are subsequently calculated, based on the measured displacement field. A finite element model of the perforated specimen is made. The difference between the experimental and numerical strains is minimized in a least squares sense by updating the values of the parameters. The obtained material (or model) parameters are very well in agreement with the traditionally determined ones. [less ▲]

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See detailIdentification of elastoplastic model in large deformation problems
Jeunechamps, Pierre-Paul ULg; Walmag, Jérôme ULg; Delhez, Eric ULg et al

in Cinquini, Carlo (Ed.) Proceedings of the 5th World Congress of Structural and Multidisciplinary Optimization WCSMO5 (2003, May)

This paper reports on preliminary results of parameter identification problems in finite element non-linear analyses such as metal forming simulations. Two approaches are compared. The first one is the ... [more ▼]

This paper reports on preliminary results of parameter identification problems in finite element non-linear analyses such as metal forming simulations. Two approaches are compared. The first one is the classic Levenberg-Marquardt algorithm. The second one is a trust-region algorithm based on a quadratic model. The two algorithms are compared on two cases, one of them being an actual experiment. [less ▲]

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See detailIdentification of elastoplastic model parameters in large deformation problems using gamma methods
Jeunechamps, Pierre-Paul ULg; Walmag, J.; Mathonet, V. et al

in Proceedings of the 5th World Congress on Structural and Multidisciplinary Optimization (2003)

This paper reports on preliminary results of parameter identification problems in finite element non-linear analyses such as metal forming simulations. Two approaches are compared. The first one is the ... [more ▼]

This paper reports on preliminary results of parameter identification problems in finite element non-linear analyses such as metal forming simulations. Two approaches are compared. The first one is the classic Levenberg-Marquardt algorithm. The second one is a trust-region algorithm based on a quadratic model. The two algorithms are compared on two cases, one of them being an actuel experiment. [less ▲]

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See detailIdentification of Electromechanical Coupling in Piezo-Structures
De Boe, Pascal; Golinval, Jean-Claude ULg

Conference given outside the academic context (2000)

An identification method based on a structural model updating procedure may be used to improve the knowledge of a piezoelectric tested structure and to determine the coupling coefficients of the ... [more ▼]

An identification method based on a structural model updating procedure may be used to improve the knowledge of a piezoelectric tested structure and to determine the coupling coefficients of the piezoelectric material. This procedure starts with the modal analysis of the open-loop instrumented structure. Let the target modes be a subset of the model modes; a selection of sensor (generally accelerometers) locations is then performed by determining the smaller subset such that the H2 modal norm is as close as possible to the modal norm of the original full set. In most cases, experimental testing with the selected sensor set will give acceptable information to identify target modes. These data, coupled with electrical sensing at the piezoelectric element level, will then be used to perform modal analysis of the piezo-structure. A pole-residue development of the open-loop piezo-structure shows that conventional algorithms may be used to estimate the mechanical modal parameters and the electromechanical coupling matrix. The second step of the procedure is to perform model updating itself. The initial finite element piezoelectric model will be improved stiffness corrections to the global stiffness matrix.. The corrections are split in their mechanical and electromechanical contributions. It is then possible to separate mechanical modelling errors from electromechanical coupling errors. The problem becomes a classical model updating problem which may be solved using well established techniques. This will result not only in a model behaving like the measures, but also in an improved knowledge of the structure behaviour without loosing physical insight. From a numerical point of view, it will be shown that ill-conditioning inherent to the presence of piezoelectric elements presents some difficulties at different steps of the model correction procedure. A clamped-free plate instrumented with piezo-laminates is used to illustrate the model updating approach. The selection of measurement points, using the modal norm criteria, is also presented. Experimental identification data will then be used as inputs for the model correction procedure and the behaviour of the updated model will be compared with the initial model dynamics. [less ▲]

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See detailIdentification of elemental sulphur (S8) in Boscia senegalensis (Pers.) Lam ex Poir. leaves.
Lognay, Georges ULg; Seck, D.; Marlier, M. et al

in Bulletin des Recherches Agronomiques de Gembloux (1993), 28(4),

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See detailIdentification of equid herpesvirus-5 in respiratory liquids: A retrospective study of 785 samples taken in 2006-2007
Fortier, Guillaume; Pronost, Stéphane; Miszczak, Fabien et al

in Veterinary Journal (2009), 182

During a case control study undertaken in 2006-2007, a screening and consensus polymerase chain reaction (PCR) was performed to evaluate the potential role of equid herpesviruses (EHV) in several ... [more ▼]

During a case control study undertaken in 2006-2007, a screening and consensus polymerase chain reaction (PCR) was performed to evaluate the potential role of equid herpesviruses (EHV) in several occurrences of respiratory disorders in 661 horses. Of 785 bronchoalveolar or tracheal lavage fluid samples submitted for analysis, 20 were positive for EHV-5 DNA by sequential analysis of the consensus PCR product. Nineteen of those samples were confirmed using a specific EHV-5 PCR. No particular changes in cytological profile could be associated with the detection of EHV-5 in contrast to suggestions in previous reports of natural or experimental respiratory viral infections in horses or ponies. This is the first description of EHV-5 isolation in equine respiratory fluids in Europe, but further investigations are needed to determine the potential pathogenic role of this gammaherpesvirus in the horse. [less ▲]

Detailed reference viewed: 109 (30 ULg)
See detailThe identification of experimental microscopic hafting traces on lithic tools
Rots, Veerle ULg

in Le Sécretariat du Congrès (Ed.) Sessions Générales et Posters / General Sessions and Posters. Acts of the XIVth UISPP Congress University of Liège, Belgium, 2 – 8 September 2001 (2003)

Detailed reference viewed: 23 (0 ULg)