Browsing
     by title


0-9 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

or enter first few letters:   
OK
Full Text
Peer Reviewed
See detailIdentification and model Updating of a non-stationary vibrating system
Dimitriadis, Grigorios ULg; Fassois, Spilios; Poulimenos, Aggelos et al

in Akay, A.; Arnas, O.; Cooper, J. E. (Eds.) et al Proceedings of 7th Biennial ASME Conference on Engineering Systems Design and Analysis (2004, July)

Non-stationary systems, which are commonly encountered in many fields of science, are characterized by time-varying features and require time-frequency methods for their analysis. This study considers the ... [more ▼]

Non-stationary systems, which are commonly encountered in many fields of science, are characterized by time-varying features and require time-frequency methods for their analysis. This study considers the problem of identification and model updating of a non-stationary vibrating system. In particular, a number of identification methods and a model updating procedure are evaluated and compared through application to a time-varying “bridge-like” laboratory structure. The identification approaches include Frequency Response Function based parameter estimation techniques, Subspace Identification and Functional Series modelling. All methods are applied to both output-only and input-out-put data. Model updating is based upon a theoretical model of the structure obtained using a Rayleigh-Ritz methodology, which is updated to account for time-dependence and nonlinearity via the identification results. Interesting comparisons, among both identification and model updating results, are performed. The results of the study demonstrate high modelling accuracy, illustrating the effectiveness of model updating techniques in non-stationary vibration modelling. [less ▲]

Detailed reference viewed: 34 (4 ULg)
Full Text
Peer Reviewed
See detailIdentification and modulation of a growth hormone-binding protein in rainbow trout (Oncorhynchus mykiss) plasma during seawater adaptation.
Sohm, F.; Manfroid, Isabelle ULg; Pezet, A. et al

in General and Comparative Endocrinology (1998), 111(2), 216-24

A soluble protein that specifically bound 125I-human growth hormone (hGH) was identified in rainbow trout plasma, using HPLC-gel filtration. The binding affinity of the protein for hGH was 1.2 x 10(9)M-1 ... [more ▼]

A soluble protein that specifically bound 125I-human growth hormone (hGH) was identified in rainbow trout plasma, using HPLC-gel filtration. The binding affinity of the protein for hGH was 1.2 x 10(9)M-1. 125I-rainbow trout GH (tGH) was also able to bind to the protein albeit with a lower affinity (6.6 x 10(7)M-1) than hGH. Crosslinking experiments using 125I-hGH revealed two specific bands of 150 and 130 kDa. The complex 125I-hGH-BP could be precipitated by a monoclonal anti-GH receptor antibody, suggesting a close relationship between the plasma GH-BP and the GH receptor. A fourfold increase in the hGH binding to the GH-BP was shown 48 h after transfer of the fishes from freshwater to seawater. The increase in binding was related to a high binding capacity without significant changes in binding affinity. These results suggest a potential role of this related GH-BP as an index of GH effects during seawater adaptation in salmonids. [less ▲]

Detailed reference viewed: 56 (3 ULg)
Full Text
Peer Reviewed
See detailIdentification and overexpression in Escherichia coli of a Mycobacterium leprae gene, pon1, encoding a high-molecular-mass class A penicillin-binding protein, PBP1
Basu, Joyoti; Mahapatra, Sebabrata; Kundu, Manikuntala et al

in Journal of Bacteriology (1996), 178(6), 1707-1711

Cosmid B577, a member of the collection of ordered clones corresponding to the genome of Mycobacterium leprae, contains a gene, provisionally called pon1, that encodes an 821-amino-acid-residue high ... [more ▼]

Cosmid B577, a member of the collection of ordered clones corresponding to the genome of Mycobacterium leprae, contains a gene, provisionally called pon1, that encodes an 821-amino-acid-residue high-molecular-mass class A penicillin-binding protein, provisionally called PBP1. With similar amino acid sequences and modular designs, M. leprae PBP1 is related to Escherichia coli PBP1a and PBP1b, bienzymatic proteins with transglycosylase and transpeptidase activities. When produced in E. coli, His tag-labelled derivatives of M. leprae PBP1 adopt the correct membrane topology, with the bulk of the polypeptide chain on the surface of the plasma membrane. They defy attempts at solubilization with all the detergents tested except cetyltrimethylammonium bromide. The solubilized PBP1 derivatives can be purified by affinity chromatography on Ni2+-nitrilotriacetic acid agarose. They have low affinities for the usual penicillins and cephalosporins. [less ▲]

Detailed reference viewed: 19 (4 ULg)
Full Text
Peer Reviewed
See detailIdentification and quantification of concentration-dependent biomarkers in MCF-7/BOS cells exposed to 17β-estradiol by 2-D DIGE and label-free proteomics
Collodoro, Mike ULg; Lemaire, Pascale ULg; Eppe, Gauthier ULg et al

in Journal of Proteomics (2012), in press

This paper reports the identification of biomarkers resulting from the exposure of MCF-7/BOS cells to 17β-estradiol (E2). The biomarkers were identified using 2 independent and complementary techniques, 2 ... [more ▼]

This paper reports the identification of biomarkers resulting from the exposure of MCF-7/BOS cells to 17β-estradiol (E2). The biomarkers were identified using 2 independent and complementary techniques, 2-D DIGE / MALDI-TOF peptide mass fingerprint, and 2-D UPLC-ESI MS/MS. These markers form a preliminary molecular signature that can be used when testing the estrogenic activity of xenobiotics, either pure or in mixtures. [less ▲]

Detailed reference viewed: 30 (15 ULg)
Full Text
Peer Reviewed
See detailIdentification and Quantification of Metabolites in a Human Plasma Standard Reference Material by Multiple Mass Spectrometry Methods
Dodder, Nathan; Barak, Ruth; Eppe, Gauthier ULg et al

in 57th ASMS Conference on Mass Spectrometry and Allied topics (2009)

Detailed reference viewed: 30 (0 ULg)
Full Text
Peer Reviewed
See detailIdentification and quantification of selected Metabolites in a Human Plasma by Two Dimensional Gas Chromatography Time of Flight Mass Spectrometry’
Eppe, Gauthier ULg; Mc Gaw, Elizabeth; Dodder, Nathan et al

in 5th International Conference of the Metabolimic Society (2009)

Detailed reference viewed: 20 (8 ULg)
Full Text
See detailIdentification and quantification of sources of major solutes in a sandy, phreatic aquifer in Central Belgium through ionic ratios and geochemical mass-balance modelling
Peeters, Luk; Batelaan, Okke; Dassargues, Alain ULg

in Groundwater and Ecosystems, Proc. of the XXXV IAH Congress (2007)

In this study the processes affecting groundwater chemistry in the Eocene Brussels sands aquifer in Central Belgium are identified based on evaluation of ionic ratios of major solutes. Based on these ... [more ▼]

In this study the processes affecting groundwater chemistry in the Eocene Brussels sands aquifer in Central Belgium are identified based on evaluation of ionic ratios of major solutes. Based on these results, in combination with mineralogical and hydrogeological information of the aquifer, a geochemical mass-balance model is created to quantify the contribution of each of the processes to the observed composition of groundwater. After a rigorous validation process, a dataset of 99 groundwater samples is obtained from observation and pumping wells in the Eocene Brussels sands aquifer, which is one of the main aquifers for drinking water production in Belgium. The aquifer consists of heterogeneous alteration of calcified and silicified coarse sands, with local presence of clay drapes and glauconite-rich zones (Laga et al. 2001). The entire aquifer is overlain by Quaternary eolian deposits, mainly consisting of loam with the exception of the north east, where the Quaternary deposits are sandy loam. The groundwater in this aquifer is of Ca-Mg-HCO3-type with locally elevated nitrate concentrations. Based on the evaluation of ionic ratios and the mineralogy of the aquifer, a conceptual geochemical model is developed for mass-balance modeling, including (1) concentration of precipitation by a factor 1 to 5 due to evaporation, (2) dissolution of a pure calcite phase and a calcite phase containing 25 % magnesium by both carbonic acid and sulfuric acid, (3) anthropogenic inputs for all major cations and anions except bicarbonate, (4) dissolution of glauconite, (5) cation exchange of sodium and potassium for calcium and magnesium. The two calcite phases can be thought of as end-members of a solid solution of magnesium in calcite. The mass-balance modeling consists of a mole-balance equation for each considered element according to: [Obs] = p[Prec] + p1[Phase 1] + ... + pi[Phase i] + a [Anthropogenic] +/- c[Cation Exchange] This set of linear equations is additionally constrained by (1) defining a range for concentration factors p based on measured and calculated evaporation rates, (2) charge balance for the anthropogenic sources and (3) pi being positive or negative according to whether the phase dissolves or precipitates. The set of linear equations with the given constraints is solved using a least squares optimization. Based on the possible processes and reactions several geochemical models are tested for each sample and a model is considered adequate if the root mean squared error (RMSE) between observed and calculated concentrations is less than 10-10 mol/L and the charge balance of the calculated composition is less than 5 %. If several models are able to explain the observed concentrations, the RMSE provides an objective measure to compare the quality of the models. The best model for each sample is selected and the spatial distribution of these models is compared to the spatial variations in lithology and land-use to asses the feasibility of the proposed models. [less ▲]

Detailed reference viewed: 56 (4 ULg)
Full Text
Peer Reviewed
See detailIdentification and Quantification of the Main Active Anticancer Alkaloids from the Root of Glaucium flavum
bournine, Lamine; Bensalem, Sihem; Wauters, Jean-Noël ULg et al

in International Journal of Molecular Sciences (2013), 14

Glaucium flavum is used in Algerian folk medicine to remove warts (benign tumors). Its local appellations are Cheqiq el-asfar and Qarn el-djedyane. We have recently reported the anti-tumoral activity of ... [more ▼]

Glaucium flavum is used in Algerian folk medicine to remove warts (benign tumors). Its local appellations are Cheqiq el-asfar and Qarn el-djedyane. We have recently reported the anti-tumoral activity of Glaucium flavum root alkaloid extract against human cancer cells, in vitro and in vivo. The principal identified alkaloid in the extract was protopine. This study aims to determine which component(s) of Glaucium flavum root extract might possess potent antitumor activity on human cancer cells. Quantitative estimation of Glaucium flavum alkaloids was realized by HPLC-DAD. Glaucium flavum effect on human normal and cancer cell viability was determined using WST-1 assay. Quantification of alkaloids in Glaucium flavum revealed that the dried root part contained 0.84% of protopine and 0.07% of bocconoline (w/w), while the dried aerial part contained only 0.08% of protopine, glaucine as the main alkaloid, and no bocconoline. In vitro evaluation of the growth inhibitory activity on breast cancer and normal cells demonstrated that purified protopine did not reproduce the full cytotoxic activity of the alkaloid root extract on cancer cell lines. On the other hand, bocconoline inhibited strongly the viability of cancer cells with an IC50 of 7.8 µM and only a low cytotoxic effect was observed against normal human cells. Our results showed for the first time that protopine is the major root alkaloid of Glaucium flavum. Finally, we are the first to demonstrate a specific anticancer effect of Glaucium flavum root extract against breast cancer cells, which can be attributed, at least in part, to bocconoline. [less ▲]

Detailed reference viewed: 18 (2 ULg)
Full Text
Peer Reviewed
See detailIdentification and Ranking of risk factors for somatic cell count economic penalty in 349 southern Belgium dairy farms
Theron, Léonard ULg; Humblet, Marie-France ULg; Delfosse, C. et al

in Maillard, R.; Navetat, H. (Eds.) European buiatrics forum 2009 (2009, December 02)

In Belgium, the main economic penalty accounted for bovine milk quality is the bulk milk somatic cell count geometric mean over 3 months reaching more than 400,000 cells/ml. Yet, it is still difficult to ... [more ▼]

In Belgium, the main economic penalty accounted for bovine milk quality is the bulk milk somatic cell count geometric mean over 3 months reaching more than 400,000 cells/ml. Yet, it is still difficult to make progress on udder health and milk quality because regional risks related to endemic farming practices are not broadly known. Hence, a first step in understanding specific udder health risks associated with herd management has to be a broad ecopathological survey. A random stratified sample of 349 dairy farms, representing 25% of producers registered for performance recording, was selected with a total of 16,000 cows. Thorough audits recording 400 farming practices were made in each farm by 2 different surveyors during milking. The practices were recorded across four categories: Herd structure, Housing, Milking practices and Herd Management (including Nutrition). Our chosen variable was the geometric mean of the herd composite somatic cell count from the last three months compared to the 400,000 cells/ml European threshold. The sample had a mean somatic cell count of 287,000 cells/ml following a normal distribution between 73,000 and 807,000 cells/ml. From 19 risk indicators identified through univariate logistic analysis (p<0.15), half were related to milking practices and 5 were underlined by significant odds-ratios (OR) found through multivariate logistic analysis (p<0.05). Therefore, it was found that cubicle housing had the least risk (OR= 0.59 compared with tightened stalls, OR= 0.42 compared with straw stalls); Presence of a calving pen (OR= 0.40), use of post-dipping (OR= 0.50) had a positive impact; whereas pre-dip had a negative impact in our study (OR= 3) though it was not clear if this routine was performed correctly. Stripping also had a bad impact on milk quality whether it was systematic (OR = 1.90) or occasional (OR = 2.43). It was also found that farms with poor milking liner hygiene had more trouble (OR = 2.34). The results were comparable to other ecopathological studies such as northern and southern American and European studies. This study is a prerequisite in operational veterinary advice in southern Belgium dairy farms, because it provides a cross-sectional study of dairy practices and states on major epidemiological risk factors in dairy management for this region. [less ▲]

Detailed reference viewed: 85 (25 ULg)
Full Text
Peer Reviewed
See detailIdentification and redshift determination of quasi-stellar objects with medium-band photometry: application to Gaia
Claeskens, Jean-François ULg; Smette, Alain; Vandenbulcke, Luc ULg et al

in Monthly Notices of the Royal Astronomical Society (2006), 367(3), 879-904

All-sky, multicolour, medium deep (V similar or equal to 20) surveys have the potentiality of detecting several hundred thousands of quasi-stellar objects (QSOs). Spectroscopic confirmation is not ... [more ▼]

All-sky, multicolour, medium deep (V similar or equal to 20) surveys have the potentiality of detecting several hundred thousands of quasi-stellar objects (QSOs). Spectroscopic confirmation is not possible for such a large number of objects, so that secure photometric identification and precise photometric determination of redshifts (and other spectral features) become mandatory. This is especially the case for the Gaia mission, in which QSOs play the crucial role of fixing the celestial referential frame, and in which more than 900 gravitationally lensed QSOs should be identified. We first built two independent libraries of synthetic QSO spectra reflecting the most important variations in the spectra of these objects. These libraries are publicly available for simulations with any instrument and photometric system. Traditional template fitting and artificial neural networks (ANNs) are compared to identify QSOs among the population of stars using broad- and medium-band photometry (BBP and MBP, respectively). Besides those two methods, a new one, based on the spectral principal components (SPCs), is also introduced to estimate the photometric redshifts. Generic trends as well as results specifically related to Gaia observations are given. We found that (i) ANNs can provide clean, uncontaminated QSO samples suitable for the determination of the reference frame, but with a level of completeness decreasing from similar or equal to 50 per cent at the Galactic pole at V= 18 to similar or equal to 16 per cent at V= 20; (ii) the chi(2) approach identifies about 90 per cent (60 per cent) of the observed QSOs at V= 18 (V= 20), at the expense of a higher stellar contamination rate, reaching similar or equal to 95 per cent in the galactic plane at V= 20. Extinction is a source of confusion and makes difficult the identification of QSOs in the galactic plane and (iii) the chi(2) method is better than ANNs to estimate the photometric redshifts. Due to colour degeneracies, the largest median absolute error (vertical bar Delta z vertical bar(Median)similar or equal to 0.2) is predicted in the range 0.5 < z(spec) < 2. The method based on the SPCs is promisingly good at recovering the redshift, in particular for V < 19 and z < 2.5 QSOs. For bright (V less than or similar to 18) QSOs, SPCs are also able to recover the spectral shape from the BBP and MBP data. [less ▲]

Detailed reference viewed: 24 (12 ULg)
Full Text
Peer Reviewed
See detailIdentification and Relative-quantification of Glycans by Matrix-assisted Laser Desorption/Ionization In-Source Decay with Hydrogen Abstraction
Akasawa, Daiki; Smargiasso, Nicolas ULg; De Pauw, Edwin ULg

in Analytical Chemistry (2012)

The use of specific matrices allows enhancing the scope of in-source decay (ISD) applications in matrix-assisted laser desorption ionization (MALDI) thanks to the specificity of analyte-matrix chemistry ... [more ▼]

The use of specific matrices allows enhancing the scope of in-source decay (ISD) applications in matrix-assisted laser desorption ionization (MALDI) thanks to the specificity of analyte-matrix chemistry. The use of an oxidizing matrix, 5-nitrosalicylic acid (5-NSA) for MALDI-ISD of glycans is shown to promote fragmentation pathways involving radical precursors. Both glycosidic and cross-ring cleavages are promoted by hydrogen abstraction from hydroxyl group of glycans by 5-NSA molecules. Cross-ring cleavage ions are potentially useful in linkage analysis, one of the most critical steps of glycan characterization. Moreover, we show here that isobaric glycans could be distinguished by structure specific ISD ions, and that the molar ratio of glycan isomers in the mixture can be estimated from their fragment ions abundance. The use of 5-NSA also opens the possibility to perform pseudo-MS3 analysis of glycans. Therefore, MALDI-ISD with 5-NSA is a useful method for identification of glycans and semi-quantitative analysis of mixture of glycan isomers. [less ▲]

Detailed reference viewed: 30 (7 ULg)
Full Text
Peer Reviewed
See detailIdentification and structure elucidation of four cannabimimetic compounds in seized products
Denooz, Raphaël ULg; VAN HEUGEN, Jean-Claude ULg; Frederich, Michel ULg et al

in Journal of Analytical Toxicology (2013), 37(2), 56-63

Since 2008, herbal mixtures with synthetic cannabinoid compounds have been sold as incense throughout the world. Although these new drugs are labeled as not for human consumption, these products are ... [more ▼]

Since 2008, herbal mixtures with synthetic cannabinoid compounds have been sold as incense throughout the world. Although these new drugs are labeled as not for human consumption, these products are smoked for their cannabis-like effects. This study reports the structural and spectral elucidation of four cannabimimetic compounds seized in Belgium: (4-methoxyphenyl)-1-(pentyl-1H-indol-3-yl)methanone (RCS-4), 1-(5-fluoropentyl)-3-(1-naphtoyl)indole (AM-2201), 2-(2-chlorophenyl)-1-(1-pentylindol-3-yl)ethanone (JWH-203) and 4-ethylnaphthalen-1-yl-(1-pentylindol-3-yl)methanone (JWH-210). Laboratory investigations were conducted by liquid chromatography (LC)–ultraviolet spectroscopy, high-resolution accurate mass detection and nuclear magnetic resonance (NMR) analysis. This combined analytical approach allowed the detection of illicit compounds for which reference materials were not available. To facilitate identification and to complete existing databases, ultraviolet spectra and NMR data of all seized products are presented. Additionally, LC–quadrupole time-of-flight data were recorded to provide absolute identification. [less ▲]

Detailed reference viewed: 68 (34 ULg)
Full Text
Peer Reviewed
See detailIdentification and subcellular distribution of endogenous Ins(1,4,5)P3 3-kinase B in mouse tissues
Hascakova-Bartova, Romana; Pouillon, Valérie; Dewaste, Valérie et al

in Biochemical and Biophysical Research Communications (2004), 323(3), 920-925

Inositol 1,4,5-trisphosphate 3-kinase (IP3-3K) catalyses the phosphorylation of inositol 1,4,5-trisphosphate to inositol 1,3,4,5-tetrakisphosphate. cDNAs encoding three mammalian isoforms have been ... [more ▼]

Inositol 1,4,5-trisphosphate 3-kinase (IP3-3K) catalyses the phosphorylation of inositol 1,4,5-trisphosphate to inositol 1,3,4,5-tetrakisphosphate. cDNAs encoding three mammalian isoforms have been reported and referred to as IP3-3KA, IP3-3KB, and IP3-3KC. IP3-3KB is particularly sensitive to proteolysis at the N-terminus, a mechanism known to generate active fragments of lower molecular mass. Endogenous IP3-3KB has therefore not been formally identified in tissues. We have probed a series of murine tissues with an antibody directed against the C-terminus of IP3-3KB and used IP3-3KB deficient mouse tissues as negative controls. IP3-3KB was shown to be particularly well expressed in brain, lung, and thymus with molecular masses of 110–120 kDa. The identification of the native IP3-3KB by Western blotting for the first time will facilitate further studies of regulation of its activity by specific proteases and/or phosphorylation [less ▲]

Detailed reference viewed: 29 (9 ULg)
Full Text
Peer Reviewed
See detailIdentification and typing of Salmonella serotypes isolated from guinea fowl (Numida meleagris) farms in Benin during four laying seasons (2007-2010)
Boko, C; Kpodekon, T; Duprez, Jean-Noël ULg et al

in Avian Pathology : Journal of the W.V.P.A (2013), 42

Detailed reference viewed: 25 (5 ULg)
Full Text
Peer Reviewed
See detailIdentification and Validation of the Methylated TWIST1 and NID2 Genes through Real-Time Methylation-Specific Polymerase Chain Reaction Assays for the Noninvasive Detection of Primary Bladder Cancer in Urine Samples.
Renard, Isabelle; Joniau, Steven; van Cleynenbreugel, Ben et al

in European urology (2010)

BACKGROUND: Accumulating evidence suggests that DNA methylation markers could serve as sensitive and specific cancer biomarkers. OBJECTIVE: To determine whether a panel of methylated genes would have the ... [more ▼]

BACKGROUND: Accumulating evidence suggests that DNA methylation markers could serve as sensitive and specific cancer biomarkers. OBJECTIVE: To determine whether a panel of methylated genes would have the potential to identify primary bladder cancer (BCa) in voided urine samples. DESIGN, SETTING, AND PARTICIPANTS: A pharmacologic unmasking reexpression analysis in BCa cell lines was initially undertaken to unveil candidate methylated genes, which were then evaluated in methylation-specific polymerase chain reaction (MSP) assays performed on DNA extracted from noncancerous and cancerous bladder tissues. The most frequently methylated genes in cancerous tissues, with 100% specificity, were retained for subsequent MSP analysis in DNA extracted from urine samples to build and validate a panel of potential methylated gene markers. Urine samples were prospectively collected at three urologic centres from patients with histologically proven BCa and processed for use in real-time MSP and cytologic analysis. Patients with nonmalignant urologic disorders were included as controls. MEASUREMENTS: A urine sample was classified as valid when >/=10 copies of the gene encoding ss-actin were measured in the urine sediment genomic DNA. Sensitivity, specificity, and predictive values of the MSP and cytology tests were assessed and compared. RESULTS AND LIMITATIONS: MSP assays performed on 466 of the 496 (94%) valid urine samples identified two genes, TWIST1 and NID2, that were frequently methylated in urine samples collected from BCa patients, including those with early-stage and low-grade disease. The sensitivity of this two-gene panel (90%) was significantly better than that of cytology (48%), with comparable specificity (93% and 96%, respectively). The positive predictive value and negative predictive value of the two-gene panel was 86% and 95%, respectively. CONCLUSIONS: Detection of the methylated TWIST1 and NID2 genes in urine sediments using MSP provides a highly (>/=90%) sensitive and specific, noninvasive approach for detecting primary BCa. TRIAL REGISTRATION: BlCa-001 study - EudraCt 2006-003303-40. [less ▲]

Detailed reference viewed: 83 (6 ULg)