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See detailEvidence of a reentrant Peierls distortion in liquid GeTe
Raty, Jean-Yves ULg; Godlevsky, V.; Ghosez, Philippe ULg et al

in Physical Review Letters (2000), 85(9), 1950-1953

The local atomic order of semiconducting liquid GeTe is studied using first-principles molecular-dynamics simulations. Our work points out a high degree of alternating chemical order in the liquid and ... [more ▼]

The local atomic order of semiconducting liquid GeTe is studied using first-principles molecular-dynamics simulations. Our work points out a high degree of alternating chemical order in the liquid and demonstrates the presence of a Peierls distortion close above the melting temperature. This distortion, absent in the high temperature crystalline structure of NaCl type, is a remnant of the atomic arrangement in the A7 low temperature crystalline phase. It disappears slowly with temperature, as the liquid evolves from a semiconducting to a metallic state. [less ▲]

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See detailEvidence of a type 1/type 2 dichotomy in the correlation between quasar optical polarization and host-galaxy/extended emission position angles
Borguet, Benoît ULg; Hutsemekers, Damien ULg; Letawe, Géraldine ULg et al

in Astronomy and Astrophysics (2008), 478

Aims.For Seyfert galaxies, the AGN unification model provides a simple and well-established explanation of the type 1/type 2 dichotomy through orientation-based effects. The generalization of this ... [more ▼]

Aims.For Seyfert galaxies, the AGN unification model provides a simple and well-established explanation of the type 1/type 2 dichotomy through orientation-based effects. The generalization of this unification model to the higher luminosity AGNs that quasars are remains a key question. The recent detection of type 2 radio-quiet quasars seems to support such an extension. We propose a further test of this scenario. Methods: On the basis of a compilation of quasar host-galaxy position angles consisting of previously published data and of new measurements performed using HST Archive images, we investigate the possible existence of a correlation between the linear polarization position angle and the host-galaxy/extended emission position angle of quasars. Results: We find that the orientation of the rest-frame UV/blue extended emission is correlated to the direction of the quasar polarization. For type 1 quasars, the polarization is aligned with the extended UV/blue emission, while these two quantities are perpendicular in type 2 objects. This result is independent of the quasar radio loudness. We interpret this (anti-)alignment effect in terms of scattering in a two-component polar+equatorial model that applies to both type 1 and type 2 objects. Moreover, the orientation of the polarization -and then of the UV/blue scattered light- does not appear correlated to the major axis of the stellar component of the host-galaxy measured from near-IR images. [less ▲]

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See detailEvidence of a verbal overshadowing effect in children
Vanootighem, Valentine ULg; Brédart, Serge ULg; Dehon, Hedwige ULg

Poster (2011, August 01)

The report of verbal descriptions of a culprit by adult witnesses may impair their later identification ability, a phenomenon known as the “verbal overshadowing effect (VO)” (Schooler & Englster-Schooler ... [more ▼]

The report of verbal descriptions of a culprit by adult witnesses may impair their later identification ability, a phenomenon known as the “verbal overshadowing effect (VO)” (Schooler & Englster-Schooler, 1990). In spite of a large body of literature on the suggestibility of children testimony, only one study has examined whether descriptions also impaired children’s identification abilities in a single group of children (8-9 years old) and no evidence of VO was found (Memon & Rose, 2002). However, some procedural details were not controlled in this experiment and the absence of a control adult group did not allow determining whether the procedure used was able to induce a VO effect. Hence, 2 experiments were conducted on several groups of children (7-8, 10-11, 13-14 years old) and adults to determine the influence of development on the VO effect. Overall, a VO effect on face identification was found in both experiments. The quality and influence of descriptors across the ages were also examined. [less ▲]

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See detailEvidence of an atypical scale development during the settlement phase of a coral reef fish
Frederich, Bruno ULg; Lecchini, David; Vandewalle, Pierre ULg

Poster (2009, April)

As the majority of coral reef fishes, the Convict Surgeonfish Acanthurus triostegus (Acanthuridae) has a complex life cycle that involves an ontogenetic change in morphology, physiology and behaviour as ... [more ▼]

As the majority of coral reef fishes, the Convict Surgeonfish Acanthurus triostegus (Acanthuridae) has a complex life cycle that involves an ontogenetic change in morphology, physiology and behaviour as its pelagic larval stage colonizes the benthic habitat. Abrupt and spectacular changes in skeletal structures occurring when a fish takes on its juvenile form were highlighted in flatfish, bonefish, tarpon, eels, pearlfish and lampreys. However, few studies are devoted to the changes in skeleton during the settlement period of demersal coral reef fishes. In the present study conducted at Rangiroa Atoll (French Polynesia), we highlight an unexpected scales development in A. trisostegus during a fifteen days period just after the reef settlement. Fish was collected during the settlement and reared in aquaria. The osseous skeleton was displayed by a standard Alizarin red S staining technique. At settlement (t0) (SL = 22-25 mm), A. triostegus showed calcified and very long plates, lying in the dermis on the whole body. After three days, some small scales developed on the caudal peduncle. The plates seemed unchanged from the head to the pectoral girdle but were thinner on the trunk. The thin plates are pricked with whitish spots, which seem to indicate a poorer fixation of the alizarin corresponding to a decalcification process. Six days after the settlement, the squamation extended anteriorly to the pectoral girdle by the addition of new scales. Thin plates were always present on the head. Then the density of scales rapidly increased along the trunk during the following three days. The scales appeared on the head nine days after the settlement. Clearly, the plates do not transform into scales. The plates disappearance and the scales appearance appear as two parallel phenomena in the development. [less ▲]

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See detailEvidence of an equilibrium between selenides and osmium(VIII) reagents and selenoxides and osmium(VI) reagents
Krief, A.; Destree, A.; Durisotti, V. et al

in Chemical Communications (2002), (6), 558-559

Driving the equilibrium between selenides and osmium( VIII) reagents with selenoxides and osmium( VI) by a subsequent reaction (rearrangement of allyl selenoxides to allyl alcohols or addition of osmium ... [more ▼]

Driving the equilibrium between selenides and osmium( VIII) reagents with selenoxides and osmium( VI) by a subsequent reaction (rearrangement of allyl selenoxides to allyl alcohols or addition of osmium( VIII) species on C C double bonds) to one side, allows the transformation of methyl geranyl selenides to linalool and of methyl citronellyl selenoxide to 6,7-dihydroxy citronellyl selenide. [less ▲]

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See detailEvidence of an intramolecular interaction between the two domains of the BlaR1 penicillin receptor during the signal transduction
Hanique, Sophie; Colombo, Maria-Luigi; Goormaghtigh, Erik et al

in Journal of Biological Chemistry (2004), 279(14), 14264-14272

The BlaR1 protein is a penicillin-sensory transducer involved in the induction of the Bacillus licheniformis beta-lactamase. The amino-terminal domain of the protein exhibits four transmembrane segments ... [more ▼]

The BlaR1 protein is a penicillin-sensory transducer involved in the induction of the Bacillus licheniformis beta-lactamase. The amino-terminal domain of the protein exhibits four transmembrane segments (TM1-TM4) that form a four-alpha-helix bundle embedded in the plasma bilayer. The carboxyl-terminal domain of 250 amino acids (BlaR-CTD) fused at the carboxyl end of TM4 possesses the amino acid sequence signature of penicillin-binding proteins. This membrane topology suggests that BlaR-CTD and the BlaR-amino-terminal domain are responsible for signal reception and signal transduction, respectively. With the use of phage display experiments, we highlight herein an interaction between BlaR-CTD and the extracellular, 63-amino acid L2 loop connecting TM2 and TM3. This interaction does not occur in the presence of penicillin. This result suggests that binding of the antibiotic to BlaR1 might entail the release of the interaction between L2 and BlaR-CTD, causing a motion of the alpha-helix bundle and transfer of the information to the cytoplasm of the cell. In addition, fluorescence spectroscopy, CD, and Fourier transform IR spectroscopy experiments indicate that in contrast to the behavior of the corresponding Staphylococcus aureus protein, the beta-lactam antibiotic does not induce a drastic conformational change in B. licheniformis BlaR-CTD. [less ▲]

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See detailEvidence of an original scale development during the settlement phase of a coral reef fish (Acanthurus triostegus)
Frederich, Bruno ULg; Lecchini, David; Vandewalle, Pierre ULg

in Journal of Applied Ichthyology (2010), 26

As the majority of coral reef fishes, the Convict Surgeonfish Acanthurus triostegus (Acanthuridae) has a complex life cycle that involves an ontogenetic change in morphology, physiology and behaviour as ... [more ▼]

As the majority of coral reef fishes, the Convict Surgeonfish Acanthurus triostegus (Acanthuridae) has a complex life cycle that involves an ontogenetic change in morphology, physiology and behaviour as its pelagic larval stage colonizes the benthic habitat. Few studies are devoted to the changes in skeleton during the settlement phase of coral reef fishes. In the present study, we highlighted an unexpected scales development in A. trisostegus just after the reef settlement. At settlement (t0), A. triostegus showed calcified and very thin vertical plates, lying in the dermis on the whole body. During the first 9 days after settlement, thin vertical plates regressed and adult scales began to appear simultaneously. At 12 days post-settlement, the whole body was covered with small scales. Overall, such a rapid skeletal transformation is an example of morphological changes dealing with metamorphosis of coral reef fishes. [less ▲]

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See detailEvidence of association between interferon regulatory factor 5 gene polymorphisms and asthma.
Wang, Chuan; Rose-Zerilli, Matthew J.; Koppelman, Gerard H. et al

in Gene (2012), 504(2), 220-5

Asthma is a heterogeneous disorder hallmarked by chronic inflammation in the respiratory system. Exacerbations of asthma are correlated with respiratory infections. Considering the implication of ... [more ▼]

Asthma is a heterogeneous disorder hallmarked by chronic inflammation in the respiratory system. Exacerbations of asthma are correlated with respiratory infections. Considering the implication of interferon regulatory factor 5 (IRF5) in innate and adaptive immunity, we investigated the preferential transmission patterns of ten IRF5 gene polymorphisms in two asthmatic family cohorts. A common IRF5 haplotype was found to be associated with asthma and the severity of asthmatic symptoms. Stratified analysis of subgroups of asthmatic individuals revealed that the associations were more pronounced in nonatopic asthmatic individuals. In addition, the risk alleles of IRF5 polymorphisms for asthma were almost completely opposite to those for autoimmune disorders. Our study provides the first evidence of association between IRF5 and asthma, and sheds light on the related but potentially distinct roles of IRF5 alleles in the pathogenesis of asthma and autoimmune disorders. [less ▲]

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See detailEvidence of cardiovascular dysfunction during Pasteurella haemolytica - induced acute pneumonia in calves
Amory, Hélène ULg; Linden, Annick ULg; Desmecht, Daniel ULg et al

in Journal of Veterinary Medicine. A, Physiology, Pathology, Clinical Medicine (1990)

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See detailEvidence of complex phylogeographic structure for the threatened rodent Leopoldamys neilli endemic to limestone karsts of Thailand
Latinne, Alice ULg; Waengsothorn, Surachit; Herbreteau, Vincent et al

Conference (2011, July 21)

Limestone karsts are highly threatened biodiversity hotspots supporting huge levels of endemic species. Karsts are patchy distributed within Southeast Asia and their isolation from one another give them ... [more ▼]

Limestone karsts are highly threatened biodiversity hotspots supporting huge levels of endemic species. Karsts are patchy distributed within Southeast Asia and their isolation from one another give them the features of “islands on the continent”. We have studied the phylogeography of Neill’s Rat Leopoldamys neilli, a threatened murine rodent species endemic to limestone karsts of Thailand, in order to assess the influence of its endemicity to karst habitat on its phylogeographic pattern. Two hundred twenty-two individuals of L. neilli were collected in 26 limestone karsts throughout the geographical range of this species and were used in this study. Phylogeographic structure and population genetics of L. neilli were investigated on the basis of two mitochondrial markers, the cytochrome b gene and the cytochrome c oxydase subunit I gene, two nuclear fragments, the β-fibrinogen intron 7 and the intron 1 of the X-linked gene G6pd, and 12 microsatellite loci. Our study gave evidence of a complex and strong geographic structure of the genetic diversity for L. neilli. Several highly differentiated genetic lineages were observed throughout Thailand. These results suggest a severe fragmentation of L. neilli’s populations, correlated to the fragmented distribution of its habitat and highlight its high endemicity to limestone karsts. In conclusion, this study revealed an unexpected high level of intraspecific diversity within L. neilli. These results consolidate the importance to strengthen the protection of limestone habitats and to preserve not only their huge interspecific but also intraspecific diversity. [less ▲]

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See detailEvidence of complex phylogeographic structure for the threatened rodent Leopoldamys neilli, in Southeast Asia
Latinne, Alice ULg; Waengsothorn, Surachit; Herbreteau, Vincent et al

in Conservation Genetics (2011), 12

Leopoldamys neilli is a threatened murine rodent species endemic to limestone karsts of Thailand. We have studied the phylogeography of L. neilli using two mitochondrial markers (cytb, COI) and one ... [more ▼]

Leopoldamys neilli is a threatened murine rodent species endemic to limestone karsts of Thailand. We have studied the phylogeography of L. neilli using two mitochondrial markers (cytb, COI) and one nuclear fragment (bfibr), in order to assess the influence of its endemicity to karst habitat. One hundred fifteen individuals of L. neilli were collected in 20 localities throughout the geographic range of this species in Thailand. Our study revealed strong geographic structure of the mtDNA genetic diversity: six highly differentiated, allopatric genetic lineages were observed in our dataset. They exhibit a very high degree of genetic divergence, low gene flow among lineages and low levels of haplotype and nucleotide diversities within lineages. Our results suggest that L. neilli’s populations are highly fragmented due to the scattered distribution of its karst habitat. The most divergent lineage includes the populations from western Thailand, which have been separated from the other genetic lineages since at least the Early Pleistocene. The other lineages are more closely related and have diverged since the Middle Pleistocene. This study revealed an unexpected high level of genetic differentiation within L. neilli and highlighted the high endemicity of this species to limestone karsts. Our results enhance the importance of protecting limestone habitats to preserve not only the species but also intraspecific diversity. [less ▲]

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See detailEvidence of cutinase activity released by Ascochyta pinodes and Ascochyta pisi.
Nasraoui, B.; Lepoivre, Philippe ULg; Barthelemy, Jean-Paul ULg et al

in Mededelingen van de Faculteit Landbouwwetenschappen (Rijksuniversiteit te Gent) (1990), 55(3a),

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See detailEvidence of food quality limitation in benthic river insects
Darchambeau, François ULg; Glémet, Hélène; Bélanger, Tommy et al

Conference (2007, July 12)

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See detailEvidence of food quality limitation in benthic river insects
Darchambeau, François ULg; Glémet, Hélène; Bélanger, Tommy et al

Conference (2007, August 16)

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See detailEvidence of health benefits of of polyphenols enriched foods : from In Vitro studies to clinical trials performed at university - CHU of Liège, Belgium
PINCEMAIL, Joël ULg; Kevers, Claire ULg; Tabart, Jessica ULg et al

in University of Ferrara (Ed.) Second Internaional conference on environmental stressors in biology and medicine (2011, October)

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See detailEvidence of HLA-mediated immune response driving the maintenance of CTL-escape variants in patients with undetectable viral load
Dilernia, D.; Lourtau, L.; Jones, L.R. et al

in AIDS Research and Human Retroviruses (2008, October 13), 4(1), 79

Evidence of HLA-mediated immune response driving the maintenance of CTL-escape variants in patients with undetectable viral load. Dario A Dilernia, L Lourtau, L Jones, S Rodriguez, C Bautista, M Gomez ... [more ▼]

Evidence of HLA-mediated immune response driving the maintenance of CTL-escape variants in patients with undetectable viral load. Dario A Dilernia, L Lourtau, L Jones, S Rodriguez, C Bautista, M Gomez-Carrillo, M Losso, and H Salomon. Immune response drives the selection of CTL-escape mutations during the course of HIV infection. After initiation of HAART, antiviral drugs exert a stronger selective force leading to a higher limitation of viral replication. Our objective was to evaluate the effectiveness of immune response as a selective force in a context of extremely reduced viral population size. Gag gene was sequenced and HLA-A and B genotyped over 108 samples from drug-naïve HIV-1 positive individuals. Associations between HLA alleles and viral polymorphisms were assessed by logistic regression. Multiple comparison corrections were addressed by the BH method (q-values). Phylogeny correction was performed by a Bayesian Markov-Chain Monte-Carlo method. Analysis of site-specific synonymous and non-synonymous substitution rate was assessed through the codon-based ML IFEL method. For four patients with viral load < 50 copies/ml (identified according to their HLA profile), RNA extraction was performed from 7 ml of plasma through an ultracentrifugation-based method and gag gene amplified through a Hi-Fi PCR. 20-40 clones were sequenced in samples obtained previously and during HAART. We found that HLA-B57 and A03 were the most efficient alleles in forcing CTL-escape, targeting mainly the previously characterized epitopes TSTLQEQIGW(p=0.0002) and RLRPGGKKK(p<10E-7), respectively. Sites under significant positive selection (p<0.05) during HAART were position 20 (within A03-restricted RLRPGGKK) for patient A02A3B35B39, position 385 (within A3-restricted RGNFRNQRK) for patient A3A31B7B45 and position 84 (within A2-restricted SLYNTVATL) for patient A2A3B39B57. Epitopes sequences of RLRPGGKKK and TSTLQEQIGWF were in the escape state for patients harboring the selective alleles. In spite of the low viral diversity achieved during HAART, we detected sites under positive selection. Our results show that during successful HAART, targeted CTL-epitopes are still forced to evolve adaptively, suggesting that CTL-mediated immune response would be able to keep driving the evolution of HIV variants even in viral population with a remarkable low replication rate. [less ▲]

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See detailEvidence of involvement of yeast proliferating cell nuclear antigen in DNA mismatch repair
Johnson, Robert; Kovvali, G.; Guzder, Sami et al

in Journal of Biological Chemistry (1996), 271(45), 27897-90

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