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See detailDistance and location processes in memory for time : An update
Bastin, Christine ULg; Friedman, William J.

Conference (2004)

Memory for times of past events depends on direct impressions of the temporal “distances” of the events in the past and the reconstruction of temporal “locations. Two studies shed light on the possible ... [more ▼]

Memory for times of past events depends on direct impressions of the temporal “distances” of the events in the past and the reconstruction of temporal “locations. Two studies shed light on the possible neurological basis of location-based processes. In an ERP study, adults performed tasks thought to bias subjects to use distance or location processes. Late frontal activity was specifically linked to location-based processes. In another study using the same tasks, aging was found to disrupt location-based processes more than distance-based processes. Age-related differences in the use of location-based processes were mediated by speed of processing and by working-memory capacities. [less ▲]

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See detailDistance and location processes in memory for time: An update
Bastin, Christine ULg; Friedman, William J.

in Proceedings of the 28th International Congress of Psychology (2005)

Memory for times of past events depends on direct impressions of the temporal “distances” of the events in the past and the reconstruction of temporal “locations. Two studies shed light on the possible ... [more ▼]

Memory for times of past events depends on direct impressions of the temporal “distances” of the events in the past and the reconstruction of temporal “locations. Two studies shed light on the possible neurological basis of location-based processes. In an ERP study, adults performed tasks thought to bias subjects to use distance or location processes. Late frontal activity was specifically linked to location-based processes. In another study using the same tasks, aging was found to disrupt location-based processes more than distance-based processes. Age-related differences in the use of location-based processes were mediated by speed of processing and by working-memory capacities. [less ▲]

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See detailDistance correlations and dynamics of liquid GeSe: An ab initio molecular dynamics study
Raty, Jean-Yves ULg; Godlevsky, V. V.; Gaspard, Jean-Pierre ULg et al

in Physical Review. B, Condensed Matter and Materials Physics (2001), 64

We analyze the structure and dynamics of semiconducting liquid GeSe using ab initio molecular-dynamics simulations. We show the local order of the liquid to be close to that of the low-temperature ... [more ▼]

We analyze the structure and dynamics of semiconducting liquid GeSe using ab initio molecular-dynamics simulations. We show the local order of the liquid to be close to that of the low-temperature crystalline phase. alpha -GeSe. In particular, we show that the Peierls distortion, which defines the a phase and vanishes in the high-temperature beta crystalline phase, reenters GeSe in the melt. Examining the distance histograms allows one to analyze the Ge environment as consisting of a Gese(3) unit and having one Ge-Ge defective bond. Evidence is presented that Peierls distortion is directly responsible for the semiconducting behavior of the melt. The calculated viscosity and electrical conductivity are in agreement with the experiment. An additional neutron-diffraction experiment indicates that this liquid structure is unmodified 200 K above the melting point. [less ▲]

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See detailDistance intertextuelle et classement des textes d'après leur structure : méthodes de découpage et analyses arborées
Longrée, Dominique ULg; Mellet, Sylvie; Luong, Xuan

in Viprey, Jean-Marie; Condé, Claude; Lelu, A. (Eds.) et al JADT 2006, 8èmes Journées internationales d’Analyse statistique des Données Textuelles (2006)

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See detailDistance learning and education for diabetes care
Leclercq, Dieudonné ULg; Lefèbvre, Pierre ULg

in Journal of the Diabetic Association of India (1997, July), 37(3), 71-76

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See detailDistant activity of comet C/2006 W3 (Christensen) as observed with Herschel
de Val-Borro, M.; Bockelée-Morvan, D.; Jehin, Emmanuel ULg et al

in Muinonen, Karri (Ed.) Asteroids, Comets, Meteors - Book of Abstracts (2014, July 01)

We aimed to measure the H_2O and dust production rates in C/2006 W3 (Christensen) with the Herschel Space Observatory at a heliocentric distance of ˜ 5 au and compare these data with previous post ... [more ▼]

We aimed to measure the H_2O and dust production rates in C/2006 W3 (Christensen) with the Herschel Space Observatory at a heliocentric distance of ˜ 5 au and compare these data with previous post-perihelion Herschel and ground-based observations at ˜ 3.3 au from the Sun (Bockelée-Morvan et al. 2010b). We have searched for emission in the H_2O and NH_3 ground-state rotational transitions at 557 GHz and 572 GHz, simultaneously, toward comet C/2006 W3 (Christensen) with the Heterodyne Instrument for the Far Infrared (HIFI) onboard Herschel on UT 1.5 September 2010. Photometric observations of the dust coma in the 70 μ m to 160 μ m channels were acquired with the Photodetector Array Camera and Spectrometer (PACS) instrument on UT 26.5 August 2010. A tentative 4-σ H_2O line emission feature was found in the spectra obtained with the HIFI wide-band and high-resolution spectrometers, from which we derive a water production rate of 2.0(5)×10^{27} molec. s^{-1}. A 3-σ upper limit for the ammonia production rate of < 1.5×10^{27} molec. s^{-1} is obtained taking into account the contribution from all hyperfine components (Biver et al. 2012). The dust thermal emission was detected in the 70-μ m to 160-μ m filters, with a more extended emission in the blue channel. We fit the radial dependence of the surface brightness with radially symmetric profiles for the blue and red bands. The dust production rates, obtained for a dust size distribution index that explains the fluxes at the photocenters of the PACS images, lie in the range 70-110 kg s^{-1}. Scaling the CO production rate measured post-perihelion at 3.20-3.32 au, these values correspond to a dust-to-gas production rate ratio in the range 0.3-0.4. The blueshift of the water line detected by HIFI suggests preferential emission from the subsolar point. However, it is also possible that water sublimation occurs in small ice-bearing grains that are emitted from an active region on the nucleus surface at a speed of ˜ 0.2 km s^{-1}. The dust production rates derived in August 2010 are roughly one order of magnitude lower than in September 2009, suggesting that the dust-to-gas production rate ratio remained approximately constant during the period when the activity became increasingly dominated by CO outgassing. These data will complement available Herschel observations of the distant activity of other comets such as 29P/Schwassmann-Wachmann 1 (Bockelée-Morvan et al. 2010a) and main-belt comets 176P/LINEAR and P/2012 T1 (PANSTARRS) (de Val-Borro et al. 2012, O'Rourke et al. 2013). [less ▲]

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See detailDistant and new mutations in CTX-M-1 beta-lactamase affect cefotaxime hydrolysis.
Perez-Llarena, Francisco J; Kerff, Frédéric ULg; Abian, Olga et al

in Antimicrobial Agents and Chemotherapy (2011), 55(9), 4361-8

The CTX-M beta-lactamases are an increasingly prevalent group of extended-spectrum beta-lactamases (ESBL). Point mutations in CTX-M beta-lactamases are considered critical for enhanced hydrolysis of ... [more ▼]

The CTX-M beta-lactamases are an increasingly prevalent group of extended-spectrum beta-lactamases (ESBL). Point mutations in CTX-M beta-lactamases are considered critical for enhanced hydrolysis of cefotaxime. In order to clarify the structural determinants of the activity against cefotaxime in CTX-M beta-lactamases, screening for random mutations was carried out to search for decreased activity against cefotaxime, with the CTX-M-1 gene as a model. Thirteen single mutants with a considerable reduction in cefotaxime MICs were selected for biochemical and stability studies. The 13 mutated genes of the CTX-M-1 beta-lactamase were expressed, and the proteins were purified for kinetic studies against cephalothin and cefotaxime (as the main antibiotics). Some of the positions, such as Val103Asp, Asn104Asp, Asn106Lys, and Pro107Ser, are located in the (103)VNYN(106) loop, which had been described as important in cefotaxime hydrolysis, although this has not been experimentally confirmed. There are four mutations located close to catalytic residues-Thr71Ile, Met135Ile, Arg164His, and Asn244Asp-that may affect the positioning of these residues. We show here that some distant mutations, such as Ala219Val, are critical for cefotaxime hydrolysis and highlight the role of this loop at the top of the active site. Other distant substitutions, such as Val80Ala, Arg191, Ala247Ser, and Val260Leu, are in hydrophobic cores and may affect the dynamics and flexibility of the enzyme. We describe here, in conclusion, new residues involved in cefotaxime hydrolysis in CTX-M beta-lactamases, five of which are in positions distant from the catalytic center. [less ▲]

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See detailDistantly related lipocalins share two conserved clusters of hydrophobic residues: use in homology modeling.
Adam, Benoit; Charloteaux, Benoît ULg; Beaufays, Jérôme ULg et al

in BMC structural biology (2008), 8(1-2), 1-18

BACKGROUND: Lipocalins are widely distributed in nature and are found in bacteria, plants, arthropoda and vertebra. In hematophagous arthropods, they are implicated in the successful accomplishment of the ... [more ▼]

BACKGROUND: Lipocalins are widely distributed in nature and are found in bacteria, plants, arthropoda and vertebra. In hematophagous arthropods, they are implicated in the successful accomplishment of the blood meal, interfering with platelet aggregation, blood coagulation and inflammation and in the transmission of disease parasites such as Trypanosoma cruzi and Borrelia burgdorferi. The pairwise sequence identity is low among this family, often below 30%, despite a well conserved tertiary structure. Under the 30% identity threshold, alignment methods do not correctly assign and align proteins. The only safe way to assign a sequence to that family is by experimental determination. However, these procedures are long and costly and cannot always be applied. A way to circumvent the experimental approach is sequence and structure analyze. To further help in that task, the residues implicated in the stabilisation of the lipocalin fold were determined. This was done by analyzing the conserved interactions for ten lipocalins having a maximum pairwise identity of 28% and various functions. RESULTS: It was determined that two hydrophobic clusters of residues are conserved by analysing the ten lipocalin structures and sequences. One cluster is internal to the barrel, involving all strands and the 310 helix. The other is external, involving four strands and the helix lying parallel to the barrel surface. These clusters are also present in RaHBP2, a unusual "outlier" lipocalin from tick Rhipicephalus appendiculatus. This information was used to assess assignment of LIR2 a protein from Ixodes ricinus and to build a 3D model that helps to predict function. FTIR data support the lipocalin fold for this protein. CONCLUSION: By sequence and structural analyzes, two conserved clusters of hydrophobic residues in interactions have been identified in lipocalins. Since the residues implicated are not conserved for function, they should provide the minimal subset necessary to confer the lipocalin fold. This information has been used to assign LIR2 to lipocalins and to investigate its structure/function relationship. This study could be applied to other protein families with low pairwise similarity, such as the structurally related fatty acid binding proteins or avidins. [less ▲]

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See detailDistemper in seals stranded on the Belgian coast during 1998 summer
Jauniaux, Thierry ULg; Desmecht, M.; Van Gompel, J. et al

in annual proceeding (1999)

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See detailThe distensibility of the central bronchial system in calves measured by means of the monofrequency oscillation technique
Reinhold, P.; Barnikol, W. K. R.; Lekeux, Pierre ULg

in Journal of Veterinary Medicine. A, Physiology, Pathology, Clinical Medicine (1993), 40

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See detailDistillation Simulated on Molecular Level
Pfennig, Andreas ULg

Conference (2003)

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See detailDistillation Simulated on Molecular Level
Pfennig, Andreas ULg

in Molecular Simulation (2004), 30(6), 361-366

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See detailDistinct behavior of mutant triosephosphate isomerase in hemolysate and in isolated form: molecular basis of enzyme deficiency
Orosz, F.; Olah, J.; Alvarez, M. et al

in Blood (2001), 98(10), 3106-12

In a Hungarian family with severe decrease in triosephosphate isomerase (TPI) activity, 2 germ line-identical but phenotypically differing compound heterozygote brothers inherited 2 independent (Phe240Leu ... [more ▼]

In a Hungarian family with severe decrease in triosephosphate isomerase (TPI) activity, 2 germ line-identical but phenotypically differing compound heterozygote brothers inherited 2 independent (Phe240Leu and Glu145stop codon) mutations. The kinetic, thermodynamic, and associative properties of the recombinant human wild-type and Phe240Leu mutant enzymes were compared with those of TPIs in normal and deficient erythrocyte hemolysates. The specific activity of the recombinant mutant enzyme relative to the wild type was much higher (30%) than expected from the activity (3%) measured in hemolysates. Enhanced attachment of mutant TPI to erythrocyte inside-out vesicles and to microtubules of brain cells was found when the binding was measured with TPIs in hemolysate. In contrast, there was no difference between the binding of the recombinant wild-type and Phe240Leu mutant enzymes. These findings suggest that the missense mutation by itself is not enough to explain the low catalytic activity and "stickiness" of mutant TPI observed in hemolysate. The activity of the mutant TPI is further reduced by its attachment to inside-out vesicles or microtubules. Comparative studies of the hemolysate from a British patient with Glu104Asp homozygosity and with the platelet lysates from the Hungarian family suggest that the microcompartmentation of TPI is not unique for the hemolysates from the Hungarian TPI-deficient brothers. The possible role of cellular components, other than the mutant enzymes, in the distinct behavior of TPI in isolated form versus in hemolysates from the compound heterozygotes and the simple heterozygote family members is discussed. [less ▲]

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See detailDistinct carbohydrate recognition domains of an invertebrate defense molecule recognize Gram-negative and Gram-positive bacteria.
Bilej, M.; De Baetselier, P.; Van Dijck, E. et al

in Journal of Biological Chemistry (2001), 276(49), 45840-7

Coelomic fluid of Eisenia foetida earthworms (Oligochaeta, Annelida) contains a 42-kDa defense molecule named CCF for coelomic cytolytic factor. By binding microbial antigens, namely the O-antigen of ... [more ▼]

Coelomic fluid of Eisenia foetida earthworms (Oligochaeta, Annelida) contains a 42-kDa defense molecule named CCF for coelomic cytolytic factor. By binding microbial antigens, namely the O-antigen of lipopolysaccharide (LPS), beta-1,3-glucans, or N,N'-diacetylchitobiose present, respectively, on Gram-negative bacteria or yeast cell walls, CCF triggers the prophenoloxidase activating pathway. We report that CCF recognizes lysozyme-predigested Gram-positive bacteria or the peptidoglycan constituent muramyl dipeptide as well as muramic acid. To identify the pattern recognition domains of CCF, deletion mutants were tested for their ability to reconstitute the prophenoloxidase cascade in E. foetida coelomic fluid depleted of endogenous CCF in the presence of LPS, beta-1,3-glucans, N,N'-diacetylchitobiose, and muramic acid. In addition, affinity chromatography of CCF peptides was performed on immobilized beta-1,3-glucans or N,N'-diacetylchitobiose. We found that the broad specificity of CCF for pathogen-associated molecular patterns results from the presence of two distinct pattern recognition domains. One domain, which shows homology with the polysaccharide and glucanase motifs of beta-1,3-glucanases and invertebrate defense molecules located in the central part of the CCF polypeptide chain, interacts with LPS and beta-1,3-glucans. The C-terminal tryptophan-rich domain mediates interactions of CCF with N,N'-diacetylchitobiose and muramic acid. These data provide evidence for the presence of spatially distinct carbohydrate recognition domains within this invertebrate defense molecule. [less ▲]

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See detailDistinct expression patterns of alpha1 (IV) and alpha5 (IV) collagen chains in cylindroma and malignant cylindroma.
Quatresooz, Pascale ULg; Pierard, Gérald ULg

in International Journal of Molecular Medicine (2005), 15(1), 27-31

Cutaneous cylindromas are considered to derive from cells of the sweat gland apparatus. The composition of the thick hyaline eosinophilic basement membrane (BM)-like zone surrounding epithelial aggregates ... [more ▼]

Cutaneous cylindromas are considered to derive from cells of the sweat gland apparatus. The composition of the thick hyaline eosinophilic basement membrane (BM)-like zone surrounding epithelial aggregates in cylindromas is similar to that of the dermo-epidermal junction. The presence of type IV collagen has been documented, but the distribution of the different constitutive a chains of collagen IV has not been studied so far. Alterations in the expression of these alpha chains have been described in some other conditions including basal cell carcinomas, testes with spermatogenic dysfunction and colorectal carcinomas. The aim was to study the distribution of the alpha1 (IV) and alpha5 (IV) collagen chains in cylindromas and malignant cylindroma, and to compare it with the BM of sweat glands. Seven cylindromas and one malignant cylindroma were studied. They were formalin-fixed and paraffin-embedded before processing for immunohistochemistry. Immunostaining was assessed using the avidin-biotin-peroxidase technique with antibodies directed to the alpha1 (IV) and alpha5 (IV) collagen chains. In all cylindromas, a thin continuous and sharply limited immunolabelling for the alpha1 (IV) collagen chain was abutted to the tumoral cell aggregates. A speckled immunoreactivity was found in the rest of the hyaline sheath. Globular structures encased in the cell aggregates also exhibited a thin peripheral rim positive for the alpha1 (IV) collagen chain. The immunoreactivity was faint and granular in the center of the globules. With the antibody directed against the alpha5 (IV) collagen chain, 3 cylindromas did not show any staining, 2 cases presented discrete focal positivity in the mid-part of the BM-like zone, and 2 cases exhibited a positive staining pattern similar to that observed for the alpha1 (IV) collagen chain, but with a focal and more discrete intensity. The malignant cylindroma showed a linear immunoreactivity for the alpha1 (IV) collagen chain undistinguishable from the pattern seen in the benign cylindromas. No immunoreactivity was present for the alpha5 (IV) collagen chain in the malignant neoplasm. As reported for other BM components, the expressions of the alpha1 (IV) and alpha5 (IV) collagen chains are altered in the BM-like zone surrounding the epithelial clumps in cylindromas. The molecular alteration is probably related to the ultrastructural particularities of this structure. The distinctive patterns of expression of the alpha1 (IV) and alpha5 (IV) collagen chains may be related to the histogenic sudoral origin of cylindromas without any relationship with the benign or malignant nature of the neoplasm. [less ▲]

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See detailDistinct Neuroendocrine mechanisms control neural activity underlying sex differences in sexual motivation and performance
Balthazart, Jacques ULg; Corbisier de Méaultsart, Céline; Ball, Gregory et al

in European Journal of Neuroscience (2013), 37(5), 735-42

Sexual behavior can be usefully parsed into an appetitive and a consummatory component. Both appetitive and consummatory male-typical sexual behaviors (respectively, ASB and CSB) are activated in male ... [more ▼]

Sexual behavior can be usefully parsed into an appetitive and a consummatory component. Both appetitive and consummatory male-typical sexual behaviors (respectively, ASB and CSB) are activated in male Japanese quail by testosterone (T) acting in the medial preoptic nucleus (POM), but never observed in females. This sex difference is based on a demasculinization (= organizational effect) by estradiol during embryonic life for CSB, but a differential activation by T in adulthood for ASB. Males expressing rhythmic cloacal sphincter movements (RCSMs; a form of ASB) or allowed to copulate display increased Fos expression in POM. We investigated Fos brain responses in females exposed to behavioral tests after various endocrine treat- ments. T-treated females displayed RCSM, but never copulated when exposed to another female. Accordingly they showed an increased Fos expression in POM after ASB but not CSB tests. Females treated with the aromatase inhibitor Vorozole in ovo and T in adulthood displayed both male-typical ASB and CSB, and Fos expression in POM was increased after both types of tests. Thus, the neural circuit mediating ASB is present or can develop in both sexes, but is inactive in females unless they are exposed to exogenous T. In contrast, the neural mechanism mediating CSB is not normally present in females, but can be pre- served by blocking the embryonic production of estrogens. Overall these data confirm the difference in endocrine controls and probably neural mechanisms supporting ASB and CSB in quail, and highlight the complexity of mechanisms underlying sexual differentiation of behavior. [less ▲]

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See detailDistinct pathological signatures after lethal avian H5N1 and swine H1N1 influenza infections suggest variable pathogenesis.
Garigliany, Mutien-Marie ULg; Habyarimana, Adélite; Van de Paar, Els et al

in International Journal of Infectious Diseases (2010)

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