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See detailIdentification of genes that function in the biogenesis and localization of small nucleolar RNAs in Saccharomyces cerevisiae.
Qiu, Hui; Eifert, Julia; Wacheul, Ludivine et al

in Molecular & Cellular Biology (2008), 28(11), 3686-99

Small nucleolar RNAs (snoRNAs) orchestrate the modification and cleavage of pre-rRNA and are essential for ribosome biogenesis. Recent data suggest that after nucleoplasmic synthesis, snoRNAs transiently ... [more ▼]

Small nucleolar RNAs (snoRNAs) orchestrate the modification and cleavage of pre-rRNA and are essential for ribosome biogenesis. Recent data suggest that after nucleoplasmic synthesis, snoRNAs transiently localize to the Cajal body (in plant and animal cells) or the homologous nucleolar body (in budding yeast) for maturation and assembly into snoRNPs prior to accumulation in their primary functional site, the nucleolus. However, little is known about the trans-acting factors important for the intranuclear trafficking and nucleolar localization of snoRNAs. Here, we describe a large-scale genetic screen to identify proteins important for snoRNA transport in Saccharomyces cerevisiae. We performed fluorescence in situ hybridization analysis to visualize U3 snoRNA localization in a collection of temperature-sensitive yeast mutants. We have identified Nop4, Prp21, Tao3, Sec14, and Htl1 as proteins important for the proper localization of U3 snoRNA. Mutations in genes encoding these proteins lead to specific defects in the targeting or retention of the snoRNA to either the nucleolar body or the nucleolus. Additional characterization of the mutants revealed impairment in specific steps of U3 snoRNA processing, demonstrating that snoRNA maturation and trafficking are linked processes. [less ▲]

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See detailIdentification of groundwater quality trends in a chalk aquifer threatened by intensive agriculture in Belgium
Batlle-Aguilar, Jordi; Orban, Philippe ULg; Dassargues, Alain ULg et al

in Hydrogeology Journal (2007), 15(8), 1615-1627

The European Union (EU) has adopted directives requiring that Member States take measures to reach a "good" chemical status of water resources by the year 2015 (Water Framework Directive: WFD). In order ... [more ▼]

The European Union (EU) has adopted directives requiring that Member States take measures to reach a "good" chemical status of water resources by the year 2015 (Water Framework Directive: WFD). In order to achieve the environmental objectives for groundwater, the identification and reversal of significant upward trends in pollutant concentrations are required. A very detailed dataset available for the Hesbaye chalk aquifer in Belgium is used to evaluate tools and to propose efficient methodologies for identifying and quantifying nitrate trends in groundwater. Results indicate that the parametric linear regression and the non-parametric Mann-Kendall tests are robust; however, the latter test seems more adequate as it does not require verification of the normality of the dataset and it provides calculated nitrate trends very comparable to those obtained using linear regression. From a hydrogeological point of view, results highlight a general upward trend in the whole groundwater basin. The extrapolation of the trend analysis results indicates that measures have to be taken urgently in order to avoid further major degradation of groundwater quality within the next 10-70 years. However, a good groundwater quality status cannot be expected in the Hesbaye aquifer for the 2015 EU WFD deadline. [less ▲]

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See detailIdentification of groundwater quality trends in a chalky aquifer threatened by intensive agriculture
Batlle-Aguilar, Jordi; Orban, Philippe ULg; Dassargues, Alain ULg et al

in Stauffer, Fr.; Dassargues, Alain (Eds.) Quantitative Geology from Multiple Sources: S10 Use of multiple sources in conditioning/calibrating groundwater flow and transport models (2006)

Diffuse groundwater contamination related to agricultural practices is a worldwide environmental problem, particularly the continuous increase in nitrate concentrations. As a response to this threat, the ... [more ▼]

Diffuse groundwater contamination related to agricultural practices is a worldwide environmental problem, particularly the continuous increase in nitrate concentrations. As a response to this threat, the European Union has adopted directives requiring that Member States take measures to reduce agricultural nitrate sources and stating that a “good” status of groundwater is required for all EU members. In order to achieve the environmental objectives for groundwater, the identification and reversal of any significant upward trend in the pollutant concentrations are required. Conclusions are drawn about the evolution of groundwater contamination by nitrates in the following decades with respect to the EU Water directive prescriptions. Measures have to be urgently taken in order to avoid major degradation of groundwater in 10 to 70 years. However, a good groundwater quality status cannot be expected for the 2015 EU Water Framework Directive (WFD). [less ▲]

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See detailIdentification of growth-hormone binding proteins (GBBPs) in cattle
Devolder, Anne; Renaville, Robert ULg; Massart, Serge et al

in Archives Internationales de Physiologie, de Biochimie et de Biophysique (1992), 100

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See detailIdentification of hardening behavior using inverse modeling and image correlation
Lecompte, D.; Cooreman, S.; Sol, H. et al

in Proceedings of the SEM annual conference and exposition 2006 (2006)

The basic principle of an inverse modeling procedure as it is used for parameter identification, is the generation of a complex and heterogeneous deformation field that contains as much information as ... [more ▼]

The basic principle of an inverse modeling procedure as it is used for parameter identification, is the generation of a complex and heterogeneous deformation field that contains as much information as possible about the parameters to be identified. One way of obtaining such a non-homogeneous deformation is by making the geometry of the specimen less regular. Another possibility is to make the loading conditions more complex. In this paper both options are actually combined by using a biaxial tensile test on a cruciform specimen in order to identify the parameters of a Swift isotropic hardening law. The yield criterion is modeled by the isotropic Von Mises criterion. The optimization technique used is a constrained gradient based Newton-type routine, which means that in every iteration step, a sensitivity calculation has to be performed in order to indicate the direction in which the parameters are to be optimized. The functional to be minimized is a least-squares expression of the discrepancy between the measured and the simulated strain fields at a certain load. The numerical routines as well as the identification results, based on simulated strain fields, are discussed. [less ▲]

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See detailIdentification of heterologous multicopy suppressors of the yeast msb3msb4 double mutation
Delroisse, Jean-Marc; Breban, Martine; Burny, Arsène et al

in Yeast (2003), 20(S291),

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See detailIdentification of heterologous multicopy suppressors of the yeast msb3msb4 double mutation
Delroisse, Jean-Marc; Breban, Martine; Burny, Arsène et al

Poster (2003)

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See detailIdentification of heterologous multicopy suppressors of the yeast msb3msb4 double mutation
Delroisse, Jean-Marc; Breban, Martine; Burny, Arsène et al

in Archives Internationales de Physiologie et de Biochimie (2003), 184

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See detailIdentification of heterologous multicopy suppressors of the yeast msb3msb4 double mutation.
Delroisse, Jean-Marc; Breban, Martine; Burny, Arsène et al

in Archives Internationales de Physiologie et de Biochimie (2003), 184

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See detailIdentification of HTF (HER2 transcription factor) as an AP-2 (activator protein-2) transcription factor and contribution of the HTF binding site to ERBB2 gene overexpression
Vernimmen, Douglas; Begon, Dominique ULg; Salvador, Christophe et al

in Biochemical Journal (2003), 370(Pt 1), 323-329

The ERBB2 gene is overexpressed in 30% of human breast cancers and this is correlated with poor prognosis. Overexpression of the ERBB2 gene is due to increased transcription and gene amplification. Our ... [more ▼]

The ERBB2 gene is overexpressed in 30% of human breast cancers and this is correlated with poor prognosis. Overexpression of the ERBB2 gene is due to increased transcription and gene amplification. Our previous studies have identified a new cis element in the ERBB2 promoter which is involved in the gene's overexpression. This cis element, located 501 bp upstream from the main ERBB2 transcription initiation site, binds a transcription factor called HTF (HER2 transcription factor). We report here the identification of HTF as an AP-2 (activator protein-2) transcription factor. The new cis element is bound by AP-2 with high affinity, compared with a previously described AP-2 binding site located 284 bp downstream. Co-transfection of an AP-2alpha expression vector with a reporter vector containing the newly identified AP-2 binding site in front of a minimal ERBB2 promoter induced a dose-dependent increase in transcriptional activity. We examined the contribution of the new AP-2 binding site to ERBB2 overexpression. For this purpose we abolished the new and/or the previously described AP-2 binding sequence by site-directed mutagenesis. The results show that the two functional AP-2 sites in the first 700 bp of the ERBB2 promoter co-operate to achieve maximal transcriptional activity. [less ▲]

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See detailIdentification of key predictors for osteoporosis through use of different analytical techniques
Sen, S. S.; Geling, O.; Messina, O. D. et al

in Osteoporosis International (2002, November), 13(Suppl.3), 27

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See detailIdentification Of Key Residues For Interaction Of Vasoactive Intestinal Peptide With Human Vpac(1) And Vpac(2) Receptors And Development Of A Highly Selective Vpac(1) Receptor Agonist - Alanine Scanning And Molecular Modeling Of The Peptide
Nicole, P.; Lins, Laurence ULg; Rouyer-Fessard, C. et al

in Journal of Biological Chemistry (2000), 275(31), 24003-12

The widespread neuropeptide vasoactive intestinal peptide (VIP) has two receptors VPAC(1) and VPAC(2). Solid-phase syntheses of VIP analogs in which each amino acid has been changed to alanine (Ala scan ... [more ▼]

The widespread neuropeptide vasoactive intestinal peptide (VIP) has two receptors VPAC(1) and VPAC(2). Solid-phase syntheses of VIP analogs in which each amino acid has been changed to alanine (Ala scan) or glycine was achieved and each analog was tested for: (i) three-dimensional structure by ab initio molecular modeling; (ii) ability to inhibit (125)I-VIP binding (K(i)) and to stimulate adenylyl cyclase activity (EC(50)) in membranes from cell clones stably expressing human recombinant VPAC(1) or VPAC(2) receptor. The data show that substituting residues at 14 positions out of 28 in VIP resulted in a >10-fold increase of K(i) or EC(50) at the VPAC(1) receptor. Modeling of the three-dimensional structure of native VIP (central alpha-helice from Val(5) to Asn(24) with random coiled N and C terminus) and analogs shows that substitutions of His(1), Val(5), Arg(14), Lys(15), Lys(21), Leu(23), and Ile(26) decreased biological activity without altering the predicted structure, supporting that those residues directly interact with VPAC(1) receptor. The interaction of the analogs with human VPAC(2) receptor is similar to that observed with VPAC(1) receptor, with three remarkable exceptions: substitution of Thr(11) and Asn(28) by alanine increased K(i) for binding to VPAC(2) receptor; substitution of Tyr(22) by alanine increased EC(50) for stimulating adenylyl cyclase activity through interaction with the VPAC(2) receptor. By combining 3 mutations at positions 11, 22, and 28, we developed the [Ala(11,22,28)]VIP analog which constitutes the first highly selective (>1,000-fold) human VPAC(1) receptor agonist derived from VIP ever described. [less ▲]

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See detailIdentification of large selective sweeps associated with major genes in cattle.
Druet, Tom ULg; Perez-Pardal, L.; Charlier, Carole ULg et al

in Animal Genetics (2013), 44(6), 758-62

Selection for new favorable variants can lead to selective sweeps. However, such sweeps might be rare in the evolution of different species for which polygenic adaptation or selection on standing ... [more ▼]

Selection for new favorable variants can lead to selective sweeps. However, such sweeps might be rare in the evolution of different species for which polygenic adaptation or selection on standing variation might be more common. Still, strong selective sweeps have been described in domestic species such as chicken lines or dog breeds. The goal of our study was to use a panel of individuals from 12 different cattle breeds genotyped at high density (800K SNPs) to perform a whole-genome scan for selective sweeps defined as unexpectedly long stretches of reduced heterozygosity. To that end, we developed a hidden Markov model in which one of the hidden states corresponds to regions of reduced heterozygosity. Some unexpectedly long regions were identified. Among those, six contained genes known to affect traits with simple genetic architecture such as coat color or horn development. However, there was little evidence for sweeps associated with genes underlying production traits. [less ▲]

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See detailIdentification of Linear and Nonlinear Systems using Signal Processing Techniques
Kerschen, Gaëtan ULg; Poncelet, Fabien ULg; Golinval, Jean-Claude ULg et al

in 26th Benelux Meeting on Systems and Control, Lommel, 2007 (2007)

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See detailIdentification of lines in the spectra of B stars
Swings, Polydore ULg; Nicolet, M.

in Astrophysical Journal (1934), 80(3), 190-199

Identifications of lines in the spectra of B stars are given. About fifty lines for which no previous identifications had been made are interpreted.

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See detailIdentification of material parameters to predict Single Point Incremental Forming forces
Bouffioux, Chantal ULg; Eyckens, P.; Henrard, Christophe et al

in International Journal of Material Forming (2008)

The purpose of this article is to develop an inverse method for adjusting the material parameters for single point incremental forming (SPIF). The main idea consists in FEM simulations of simple tests ... [more ▼]

The purpose of this article is to develop an inverse method for adjusting the material parameters for single point incremental forming (SPIF). The main idea consists in FEM simulations of simple tests involving the SPIF specificities (the “line test”) performed on the machine used for the process itself. This approach decreases the equipment cost. It has the advantage that the material parameters are fitted for heterogeneous stress and strain fields close to the ones occurring during the actual process. A first set of material parameters, adjusted for the aluminum alloy AA3103 with classical tests (tensile and cyclic shear tests), is compared with parameters adjusted by the line test. It is shown that the chosen tests and the strain state level have an important impact on the adjusted material data and on the accuracy of the tool force prediction reached during the SPIF process. [less ▲]

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See detailIdentification of material parameters using bi-axial machine
Flores, Paulo; de Montleau, P.; Mathonet, V. et al

in Stören, Sigurd (Ed.) Proceedings of the 7th ESAFORM conference on Materials Forming (2004)

Experimental testing equipment is built in order to identify material parameters of complex phenomenological constitutive laws. This equipment consists in a bi-axial test machine able to perform plane ... [more ▼]

Experimental testing equipment is built in order to identify material parameters of complex phenomenological constitutive laws. This equipment consists in a bi-axial test machine able to perform plane strain and simple shear tests separately or simultaneously and a Miyauchi simple shear test device; an optical extensometer is used to identify the strain field. The article focus on the validation of the results of this new equipment by comparing with results obtained by standard machines and/or by using FEM simulations of already identified materials. The first results show that the bi-axial machine performs the plane strain test optimally and some modifications are proposed in order to improve the results for the simple shear test. Miyauchi device shows a good performance and the experimental results are compared with a FEM simulation. [less ▲]

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See detailIdentification of mechanical systems with local nonlinearities through discrete-time Volterra series and Kautz functions
Shiki, Sidney Bruce; Noël, Jean-Philippe ULg; Kerschen, Gaëtan ULg et al

in Proceedings of the 11th International Conference on Recent Advances in Structural Dynamics (2013, July)

Mathematical modeling of mechanical structures is an important research area in structural dynamics. One of the goals of this area is to obtain a model that accurately predicts the dynamics of the system ... [more ▼]

Mathematical modeling of mechanical structures is an important research area in structural dynamics. One of the goals of this area is to obtain a model that accurately predicts the dynamics of the system. However, the nonlinear eff ects caused by large displacements and boundary conditions like gap, backlash or joint are not as well understood as the linear counterpart. This paper identifies a non-parametric discrete-time Volterra model of a benchmark nonlinear structure consisting of a cantilever beam connected to a thin beam at its free end. Time-domain data experimentally measured are used to identify the Volterra kernels, which are expanded with orthogonal Kautz functions to facilitate the identification process. The nonlinear parameters are then estimated through a model updating process involving optimization of the residue between the numerical and experimental kernels. The advantages and drawbacks of the Volterra series for modeling the behavior of nonlinear structures are finally indicated with suggestions to overcome the disadvantages found during the tests. [less ▲]

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