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See detailCharacterization of the MgO2+ dication in the gas phase: electronic states, spectroscopy and atmospheric implications
Linguerri, Roberto; Hochlaf, Majdi; Baccus-Montabonel, Marie-Christine et al

in Physical Chemistry Chemical Physics [=PCCP] (2013), 15(3), 824-831

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See detailCharacterization of the Micrococcus lysodeikticus type of peptidoglycan in walls of other Micrococcaceae
Campbell, J. N.; Leyh-Bouille, Mélina; Ghuysen, Jean-Marie ULg

in Biochemistry (1969), 8(1), 193-200

Peptidoglycans in walls of Micrococcus lysodeikticus, Micrococcus flavus, Micrococcus citreus, and Sarcina lutea are, composed of Nα-[L-alanyl-γ-(α-D-glutamylglycine)]-L-lysyl-D-alanine subunits, cross ... [more ▼]

Peptidoglycans in walls of Micrococcus lysodeikticus, Micrococcus flavus, Micrococcus citreus, and Sarcina lutea are, composed of Nα-[L-alanyl-γ-(α-D-glutamylglycine)]-L-lysyl-D-alanine subunits, cross-linked through D-alanyl-L-alanine and Nє-(D-alanyl)-L-lysine linkages, and do not contain any additional intervening amino acids. The D-alanyl-L-alanine peptide cross-linkages largely predominate. Although the number of peptide subunits is generally, but not always, greater than the number of disaccharide units in the glycan moiety, not all of the N-acetylmuramic acid residues are peptide substituted. Such a structure is of taxonomic importance since it differentiates the four aforementioned species from other members of the family Micrococcaceae. In Micrococcus lysodeikticus, Micrococcus flavus, and Sarcina lutea, segments of the glycan, consisting of 8-18 disaccharide units, are linked through 1 muramic acid phosphate to a segment, consisting of about 10 glucose residues, of a second wall polymer. [less ▲]

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See detailCharacterization of the negative regulatory protein PHO80 involved in transcriptional regulation of PHO5 in Saccharomyces cerevisiae
Jacqmin, S.; Gilliquet, V.; Portetelle, Daniel ULg et al

in Archives Internationales de Physiologie, de Biochimie et de Biophysique (1993), 101

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See detailCharacterization of the neurotoxicity induced by the extract of Magnistipula butayei (Chrysobalanaceae) in rat: Effects of a new natural convulsive agent
Karangwa, Charles; Esters, Virginie ULg; Tits, Monique ULg et al

in Toxicon (2007), 49(8), 1109-1119

This study was designed to document convulsant and neurotoxic properties of extracts of a tropical tree, Magnistipula butayei subsp. Montana, and to investigate the involvement of the glutamatergic system ... [more ▼]

This study was designed to document convulsant and neurotoxic properties of extracts of a tropical tree, Magnistipula butayei subsp. Montana, and to investigate the involvement of the glutamatergic system in these effects. Continuous behavioral observations and electroencephalographic (EEG) records were obtained after per os administration of an aqueous extract of Magnistipula (MBMAE) in rats. MBMAE (800 mg/kg) induced behavioral changes resembling motor limbic seizures: staring and head tremor, automatisms, forelimb clonic movements and violent tonic-clonic seizures leading to death in all animals. Concomitantly, important seizure activity that gradually evolved to epileptiform activity was recorded on the EEG. Moreover, c-Fos immunohistochemistry has revealed an increased c-Fos expression in the dentate gyrus and in piriform, peri- and entorhinal cortices 2 and 4h after treatment. This expression pattern suggested that the mechanism of action for the MBMAE is similar to that observed in glutamate-induced models of epilepsy. The MBMAE increased cell death also in hippocampal cell cultures. Furthermore, the build-up of convulsive activity and epileptic discharges induced by MBMAE in rat were abolished by MK-801, an NMDA receptor antagonist. Our study suggests that MBMAE contains a potent toxin, with a powerful neurotoxic activity in rat, and corresponding to a new natural component(s) that act as an NMDA-mediated convulsant molecule. [less ▲]

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See detailCharacterization of the new AmpC beta-lactamase FOX-8 reveals a single mutation, Phe313Leu, located in the R2 loop that affects ceftazidime hydrolysis.
Perez-Llarena, Francisco Jose; Kerff, Frédéric ULg; Zamorano, Laura et al

in Antimicrobial agents and chemotherapy (2013), 57(10), 5158-61

A novel class C beta-lactamase (FOX-8) was isolated from a clinical strain of Escherichia coli. The FOX-8 enzyme possessed a unique substitution (Phe313Leu) compared to FOX-3. Isogenic E. coli strains ... [more ▼]

A novel class C beta-lactamase (FOX-8) was isolated from a clinical strain of Escherichia coli. The FOX-8 enzyme possessed a unique substitution (Phe313Leu) compared to FOX-3. Isogenic E. coli strains carrying FOX-8 showed an 8-fold reduction in resistance to ceftazidime relative to FOX-3. In a kinetic analysis, FOX-8 displayed a 33-fold reduction in kcat/Km for ceftazidime compared to FOX-3. In the FOX family of beta-lactamases, the Phe313 residue located in the R2 loop affects ceftazidime hydrolysis and alters the phenotype of E. coli strains carrying this variant. [less ▲]

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See detailA characterization of the ordered weighted averaging functions based on the ordered bisymmetry property
Marichal, Jean-Luc; Mathonet, Pierre ULg

in IEEE Transactions on Fuzzy Systems (1999), 7(1),

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See detailCharacterization of the physical state of spray-dried inulin
Ronkart, S. N.; Deroanne, C.; Paquot, Michel ULg et al

in Food Biophysics (2007), 2

Modulated differential scanning calorimetry, wide angle x-ray scattering, and environmental scanning electron microscopy were used to investigate the physical and morphological properties of chicory root ... [more ▼]

Modulated differential scanning calorimetry, wide angle x-ray scattering, and environmental scanning electron microscopy were used to investigate the physical and morphological properties of chicory root inulin spray dried under different conditions. When the feed temperature increased up to 80 degrees C, the average degree of polymerization of the solubilized fraction increased, leading to a higher glass transition temperature (Tg). Above 80 degrees C, the samples were completely amorphous, and the Tg did not change. The starting material was semicrystalline, and the melting region was composed of a dual endotherm; the first peak subsided as the feed temperature increased up to a temperature of 70 degrees C, whereas above 80 degrees C, no melting peak was observed as the samples were completely amorphous. To a lesser extent, the inlet air temperature of 230 degrees C allowed a higher amorphous content of the samples than at 120-170 degrees C but induced a blow-out of the particles. [less ▲]

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See detailCharacterization of the physical state of spray-dried inulin.
Ronkart, Sébastien; Deroanne, Claude; Paquot, Michel ULg et al

Poster (2007, October 11)

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See detailCharacterization of the physiological work by measurement of plasma cortisol values in horses competing in 5 different sports disciplines
Linden, Annick ULg; Massart-Leen, M.; Art, Tatiana ULg et al

in Archives Internationales de Physiologie et de Biochimie (1990, February)

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See detailCharacterization of the placoderm (Gnathostomata) assemblage from the tetrapod-bearing locality of Strud (Belgium, Upper Famennian)
Olive, Sébastien ULg; Clément, Gaël; Daeschler, Edward et al

in Palaeontology (2015), 58(6), 981-1002

The placoderm fauna of the late Famennian tetrapod-bearing locality of Strud, Belgium, is studied on the basis of historical and newly collected material. It includes the previously described antiarch ... [more ▼]

The placoderm fauna of the late Famennian tetrapod-bearing locality of Strud, Belgium, is studied on the basis of historical and newly collected material. It includes the previously described antiarch Grossilepis rikiki, the groenlandaspidid Turrisaspis strudensis sp. nov. and the actinolepidoideid Phyllolepis undulata. P. undulata is thoroughly described and joins the list of the valid Phyllolepis species confidently diagnosed. A morphometrical analysis performed on the centronuchal and anterior ventrolateral plates of the Phyllolepis material demonstrates that there is only one species of Phyllolepis in Belgium (thus, Phyllolepis konincki becomes a junior synonym of P. undulata), that P. rossimontina (Pennsylvania) is a synonym of P. undulata and that the unity of the genus Phyllolepis is strongly supported, although the characterization of several species within this genus is blurred. The strong resemblance between the faunal compositions in Strud and Red Hill (Pennsylvania, USA) suggests important faunal exchanges between these regions of the Euramerica landmass. [less ▲]

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See detailCharacterization of the porous structure of biodegradable scaffolds obtained with supercritical CO2 as foaming agent
Léonard, Angélique ULg; Calberg, Cédric ULg; Kerckhofs, Greet ULg et al

in Journal of Porous Materials (2008), 15(4), 397-403

Poly(ε-caprolactone) foams were prepared, via a batch process, by using supercritical CO2 as foaming agent. Their porous structure was characterized through mercury porosimetry, helium and mercury ... [more ▼]

Poly(ε-caprolactone) foams were prepared, via a batch process, by using supercritical CO2 as foaming agent. Their porous structure was characterized through mercury porosimetry, helium and mercury pycnometry, scanning electron microscopy (SEM) and X-ray microtomography observations coupled with image analysis. The pore size distributions obtained by these two latter techniques show that the pore structure is more homogeneous when the foaming process is performed under a high CO2 saturation pressure (higher than 250 bars). [less ▲]

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See detailCharacterization of the potato mitochondrial transcription unit containing 'native' trnS (GCU), trnF (GAA) and trnP (UGG)
Remacle, Claire ULg; MarechalDrouard, L.

in Plant Molecular Biology (1996), 30(3), 553-563

In order to identify the sequences promoting the expression of plant mitochondrial tRNA genes, we have characterized the trnS (GCU), trnF (GAA) and trnP (UGG) transcription unit of the potato ... [more ▼]

In order to identify the sequences promoting the expression of plant mitochondrial tRNA genes, we have characterized the trnS (GCU), trnF (GAA) and trnP (UGG) transcription unit of the potato mitochondrial genome. These three tRNA genes were shown to be co-transcribed as a 1800 nt long primary transcript. The transcription initiation site located 305 to 312 nt upstream of trnS is surrounded by a purine-rich region but does not contain the consensus motif proposed as a promoter element in dicotyledonous plants. Differential labelling of potato mitochondrial RNA with either guanylyltransferase or T4 polynucleotide kinase suggests that this site corresponds to the unique functional region responsible for the transcription of these three tRNA genes. The initiation site recently found upstream of Oenothera mitochondrial rr trnF does not seem to be used in potato mitochondria, although a very similar sequence is present 317 nt upstream of the corresponding potato gene. Major processing sites were identified at the 3' end of each tRNA gene. Another processing site, surrounded by a double hairpin structure, is located 498 nt downstream of trnP in stretch of 10 A residues. As judged from northern experiments, this region is close to the determination site of this transcription unit. [less ▲]

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See detailCharacterization of the primary sonic muscles in Carapus acus (Carapidae): a multidisciplinary approach
Parmentier, Eric ULg; Gennotte, Vincent ULg; Focant, Bruno et al

in Proceedings of the Royal Society B : Biological Sciences (2003), 270(1530), 2301-2308

Sound production in carapid fishes results from the action of extrinsic muscles that insert into the swim bladder. Biochemical, histochemical and morphological techniques were used to examine the sonic ... [more ▼]

Sound production in carapid fishes results from the action of extrinsic muscles that insert into the swim bladder. Biochemical, histochemical and morphological techniques were used to examine the sonic muscles and compare them with epaxial muscles in Carapus acus. Sonic fibres are thicker than red and thinner than white epaxial fibres, and sonic fibres and myofibrils exhibit an unusual helicoidal organization: the myofibrils of the centre are in a straight line whereas they are more and more twisted towards the periphery. Sonic muscles have both features of red (numerous mitochondria, high glycogen content) and white (alkali-stable ATPase) fibres. They differ also in the isoforms of the light chain (LC3) and heavy chain (HC), in having T tubules at both the Z-line and the A–I junction and in a unique parvalbumin isoform (PAI) that may aid relaxation. All these features lead to the expression of two assumptions about sound generation: the sonic muscle should be able to perform fast and powerful contractions that provoke the forward movement of the forepart of the swim bladder and the stretching and ‘flapping’ of the swim bladder fenestra; the helicoidal organization allows progressive drawing of the swim bladder fenestra which emits a sound when rapidly released in a spring-like manner. [less ▲]

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See detailCharacterization of the proneural gene regulatory network during mouse telencephalon development.
Gohlke, Julia M; Armant, Olivier; Parham, Frederick M et al

in BMC Biology (2008), 6

BACKGROUND: The proneural proteins Mash1 and Ngn2 are key cell autonomous regulators of neurogenesis in the mammalian central nervous system, yet little is known about the molecular pathways regulated by ... [more ▼]

BACKGROUND: The proneural proteins Mash1 and Ngn2 are key cell autonomous regulators of neurogenesis in the mammalian central nervous system, yet little is known about the molecular pathways regulated by these transcription factors. RESULTS: Here we identify the downstream effectors of proneural genes in the telencephalon using a genomic approach to analyze the transcriptome of mice that are either lacking or overexpressing proneural genes. Novel targets of Ngn2 and/or Mash1 were identified, such as members of the Notch and Wnt pathways, and proteins involved in adhesion and signal transduction. Next, we searched the non-coding sequence surrounding the predicted proneural downstream effector genes for evolutionarily conserved transcription factor binding sites associated with newly defined consensus binding sites for Ngn2 and Mash1. This allowed us to identify potential novel co-factors and co-regulators for proneural proteins, including Creb, Tcf/Lef, Pou-domain containing transcription factors, Sox9, and Mef2a. Finally, a gene regulatory network was delineated using a novel Bayesian-based algorithm that can incorporate information from diverse datasets. CONCLUSION: Together, these data shed light on the molecular pathways regulated by proneural genes and demonstrate that the integration of experimentation with bioinformatics can guide both hypothesis testing and hypothesis generation. [less ▲]

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See detailCharacterization of the proteins encoded by the Bacillus subtilis yoxA-dacC operon.
Duez, Colette ULg; Zervosen, Astrid ULg; Teller, Nathalie et al

in FEMS Microbiology Letters (2009), 300

Abstract In Bacillus subtilis, the yoxA and dacC genes were proposed to form an operon. The yoxA gene was overexpressed in Escherichia coli and its product fused to a polyhistidine tag was purified. An ... [more ▼]

Abstract In Bacillus subtilis, the yoxA and dacC genes were proposed to form an operon. The yoxA gene was overexpressed in Escherichia coli and its product fused to a polyhistidine tag was purified. An aldose-1-epimerase or mutarotase activity was measured with the YoxA protein that we propose to rename as GalM by analogy with its counterpart in E. coli. The peptide d-Glu-delta-m-A(2)pm-d-Ala-m-A(2)pm-d-Ala mimicking the B. subtilis and E. coli interpeptide bridge was synthesized and incubated with the purified dacC product, the PBP4a. A clear dd-endopeptidase activity was obtained with this penicillin-binding protein, or PBP. The possible role of this class of PBP, present in almost all bacteria, is discussed. [less ▲]

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See detailCharacterization of the regulatory functions of varicella-zoster virus open reading frame-4 gene-product
Defechereux, Patricia; Melen-Lamalle, Laurence ULg; Baudoux, Laurence et al

in Journal of Virology (1993), 67(7), 4379-4385

Varicella-zoster virus (VZV) open reading frame 4 (ORF4) encodes a protein with a predicted molecular weight of 51,540 presenting amino acid sequence homology with the immediate-early regulatory protein ... [more ▼]

Varicella-zoster virus (VZV) open reading frame 4 (ORF4) encodes a protein with a predicted molecular weight of 51,540 presenting amino acid sequence homology with the immediate-early regulatory protein ICP27 of herpes simplex virus type 1. To investigate the regulatory properties of the ORF4 gene product, we performed a series of transient expression assays in Vero cells, using a plasmid expressing ORF4 as effector and several VZV genes and heterologous genes as targets. The VZV target plasmids contained promoter/regulatory regions from genes belonging to the three putative VZV kinetic classes fused to the chloramphenicol acetyltransferase (CAT) gene. The heterologous target plasmids consisted of promoter/regulatory regions of human cytomegalovirus, Rous sarcoma virus, and human immunodeficiency virus type 1 fused to the reporter gene. These experiments demonstrated that the ORF4 gene product activated expression of ORF62 in a dose-dependent fashion but had no effect on the expression of the three other putative immediate-early genes (ORF4, ORF61, and ORF63). When various amounts of ORF4 were transfected in the presence of early gene promoters, dose-dependent transactivation was evidenced with the thymidine kinase gene (ORF36) and the major DNA-binding protein gene (ORF29) promoters; interestingly, little activity was detected with the promoter of the DNA polymerase gene (ORF28). No activation of late gene expression, represented by the glycoprotein I and glycoprotein II genes, was seen even over a wide range of concentrations of input ORF4 plasmid. Expression of pCMVCAT, pRSVCAT, and pHIVCAT was also stimulated by the ORF4 gene product. CAT mRNA analysis showed that activation of VZV target promoters occurs at the transcriptional and/or posttranscriptional level. [less ▲]

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See detailCharacterization of the resistance of SJL/J mice to pneumonia virus of mice, a model for infantile bronchiolitis due to a respiratory syncytial virus
Glineur, Stéphanie ULg; bui tran anh, dao; Sarlet, Michaël ULg et al

in PLoS ONE (2012), 7(10), 44581

Respiratory syncytial virus (RSV), a prominent cause of airway morbidity in children, maintains an excessive hospitalization rate despite decades of research. Host factors are assumed to influence the ... [more ▼]

Respiratory syncytial virus (RSV), a prominent cause of airway morbidity in children, maintains an excessive hospitalization rate despite decades of research. Host factors are assumed to influence the disease severity. As a first step toward identifying the underlying resistance mechanisms, we recently showed that inbred mouse strains differ dramatically as regards their susceptibility to pneumonia virus of mice (PVM), the murine counterpart of RSV. PVM infection in mice has been shown to faithfully mimic the severe RSV disease in human infants. This study aimed at dissecting the remarkable PVM-resistance shown by the SJL/J strain. To characterize its genetic component, we assessed clinical, physiopathological, and virological resistance/susceptibility traits in large first (F1) and second (F2) generations obtained by crossing the SJL/J (resistant) and 129/Sv (susceptible) strains. Then, to acquire conclusive in vivo evidence in support of the hypothesis that certain radiosensitive hematopoietic cells might play a significant role in PVM-resistance, we monitored the same resistance/susceptibility traits in mock- and γ-irradiated SJL/J mice. Segregation analysis showed that (i) PVM-resistance is polygenic, (ii) the resistance alleles are recessive, and (iii) all resistance-encoding alleles are concentrated in SJL/J. Furthermore, there was no alteration of SJL/J PVM resistance after immunosuppression by γ-irradiation, which suggests that adaptive immunity is not involved. We conclude that host resistance to pneumoviruses should be amenable to genetic dissection in this mouse model and that radioresistant lung epithelial cells and/or alveolar macrophages may control the clinical severity of pneumovirus-associated lung disease. [less ▲]

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See detailCharacterization of the response of GFP microbial biosensors sensitive to substrate limitation in scale-down bioreactors
Delvigne, Frank ULg; Brognaux, Alison ULg; Gorret, Nathalie et al

in Biochemical Engineering Journal (2011), 55(2), 131-139

The dynamics of microbial stress response in intensive cultivation conditions remains not completely understood. In this work, two green fluorescent protein (GFP) transcriptional reporters have been used ... [more ▼]

The dynamics of microbial stress response in intensive cultivation conditions remains not completely understood. In this work, two green fluorescent protein (GFP) transcriptional reporters have been used as biosensors of the heterogeneities generated in a two-compartment scale-down reactor. The stress promoters have been chosen for their responsiveness to carbon limitation corresponding to the global substrate profiles encountered in intensive fed-batch cultures. From our results, it can be concluded that the exposure of microbial cells to substrates heterogeneities tends to decrease the GFP expression level in fed-batch mode. Fluorescence intensities have been monitored at the single cell level by using flow cytometry. During the course of the fed-batch culture, a drop at the level of the intracellular GFP content has been observed for the two scale-down operating conditions and for the two promoters sensitive to substrate limitation (rpoS and csiE). The fluorescence drop can be attributed to the repression of these promoters but also to the release of GFP to the extracellular medium according to the increase of the fluorescence level of the supernatant. This leakage has been observed for all the operating conditions, i.e. the scale-down reactors and the culture operating in the normal mode, i.e. in a well-mixed bioreactor. Interestingly, GFP leakage is more pronounced in the case of the cultures operated in the normal mode. Indeed, staining by propidium iodide tends to be more elevated for the microbial cells cultured under the normal mode by comparison with those cultured in scale-down conditions, indicating a higher permeability of the membrane. These results suggest that GFP microbial biosensors could be used to detect simultaneously mixing imperfections and their impact on the viability of microorganisms. [less ▲]

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See detailCharacterization of the skin using capacitance imaging.
Xhauflaire, Emmanuelle ULg; Paquet, Philippe ULg; Quatresooz, Pascale ULg et al

in Expert Review of Dermatology (2010), 5

Detailed reference viewed: 18 (2 ULg)