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See detailTrophic position of Antarctic amphipods: enhanced analysis by a 2-dimensional biomarker assay
Nyssen, Fabienne ULg; Brey, Thomas; Dauby, Patrick et al

in Marine Ecology. Progress Series (2005), 300

The discrepancy between the ecological significance of amphipods in the Antarctic and our poor knowledge of their ecofunctional role calls for a more detailed investigation of their trophic status in this ... [more ▼]

The discrepancy between the ecological significance of amphipods in the Antarctic and our poor knowledge of their ecofunctional role calls for a more detailed investigation of their trophic status in this ecosystem. A total of 12 amphipod species from suspension feeder to scavenger have been considered in this study. Our objective was to investigate whether the combination of fatty-acid and stable-isotope signatures into a 2-dimensional trophic biomarker assay would increase accuracy in the identification of Antarctic benthic amphipod trophic position. Amphipod isotopic averages ranged from -29.3 parts per thousand (delta(13)C) and 4.1 parts per thousand (delta(15)N) for the suspension feeder Ampelisca richardsoni to -21.7 parts per thousand (delta(13)C) and 11.9 parts per thousand (delta(15)N) for the high predator Iphimediella sp. Cluster analysis of the fatty-acid composition separated the amphipod species into 4 trophic groups: suspension feeders, macroherbivores, omnivores and scavengers. The suspension feeder was isolated due to an important proportion of 18:4(n-3), a fatty-acid biomarker of phytoplankton. Macro-herbivores were found to rely heavily on macroalgal carbon, containing a high percentage of arachidonic acid (20:4(n-6)). Scavenger amphipods revealed a unique fatty-acid composition dominated by 1 single fatty acid, 18:1(n-9), probably the result of a very intensive de novo biosynthesis to cope with starvation periods. Our data emphasise the need to combine different types of information to be able to draw the right conclusions regarding trophic ecology. Indeed, in some cases, the exclusive use of 1 type of tracing method, fatty acids or stable isotopes, would have resulted in misleading/false conclusions in the trophic classification of amphipods. Therefore, a 2-dimensional biomarker assay is a useful tool to elucidate the trophic positions of benthic amphipods. [less ▲]

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See detailParamètres hydrologiques et physico-chimiques de sources du Crétacé du Pays de Herve et de la Hesbaye sèche
Mols, J.; Petit, François ULg

in Bulletin de la Société Géographique de Liège (2005)

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See detailDans l'atelier du sculpteur Thoutmose
Laboury, Dimitri ULg

in Cannuyer, Christian (Ed.) La langue dans tous ses états. Michel Malaise in honorem (2005)

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See detailContribution à l’étude de l’avifaune de l’île Santay, Equateur
Marechal, Corinne ULg; Hernandez, José Francisco

in Cahiers d'Ethologie (2005), 22(1), 31-42

The avifauna of the Santay island (Guayaquil, Ecuador) has been studied during a six-months period from September 2000 to February 2001. Nearly half covered by mangrove forest, the island (2 200 ha) has ... [more ▼]

The avifauna of the Santay island (Guayaquil, Ecuador) has been studied during a six-months period from September 2000 to February 2001. Nearly half covered by mangrove forest, the island (2 200 ha) has recently been put on the list of the Ramsar Convention. However, very few data exist about its natural resources. The present results are compared to a previous study carried out in 1994. On the whole 130 birds species have been listed in Santay (48 new for the island) among which 20 Emberizidae, 18 Tyrannidae, 16 diurnal raptors, 20 endemic species to Ecuador, Colombia or Peru, 12 migrating species and 10 species both resident and migrating. Some of these species present abundant populations. Several taxa are considered as threatened. These results confirm the high biological value of the island and involve an important potential for the development of ecotouristic activities. [less ▲]

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See detailA Quadrangular Shell Finite Element for Concrete and Steel Structures Subjected to Fire
Talamona, Didier; Franssen, Jean-Marc ULg

in Journal of Fire Protection Engineering (2005), 15

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See detailRelativiser les performances des établissements scolaires : quelle valeur ajoutée ?
Lafontaine, Dominique ULg

in Demeuse, Marc (Ed.) Vers une école juste et efficace : 26 contributions sur les systèmes d'enseignement et de formation : une approche internationale (2005)

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See detailSAFIR: A thermal/structural program for modeling structures under fire
Franssen, Jean-Marc ULg

in Engineering Journal-American Institute of Steel Construction Inc (2005), 42(3), 143-158

This paper describes the fundamental of the computer code SAFIR written for the simulation of structures subjected to fire

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See detailCompte rendu de "Raymond Trousson, La Légende de la Jeune Belgique, Bruxelles, A.R.L.L.F., 2000"
Dozo, Björn-Olav ULg

in Textyles : Revue des Lettres Belges de Langue Française (2005), 26-27

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See detailThe 8 learning Events Model and its principles (Release 2005-1)
Leclercq, Dieudonné ULg; Poumay, Marianne ULg

Learning material (2005)

we have developed a theoretical reference model that has three components: (1) A series of Learning Events (LE), seeking to describe and conceive the multiplicity of learning/teaching experiences and ... [more ▼]

we have developed a theoretical reference model that has three components: (1) A series of Learning Events (LE), seeking to describe and conceive the multiplicity of learning/teaching experiences and their underpinning psychological theories ; (2) a series of Principles helping in designing and evaluating learning environments, and their underpinning educational theories ; (3) a series of more specific descriptors, or metadata, that provide detailed information about the Learning Events, enabling to judge their intrinsic qualities, their underpinning theories (from media properties to group work rules) and their degree of appropriateness to specific learners and situations. The present document is a short description of the two first components: LE and Principles. [less ▲]

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See detailCompte rendu de "Jean Ray / John Flanders, Œuvres complètes. La Flandre libérale, Tome 2, Amicale Jean Ray, 2003"
Dozo, Björn-Olav ULg

in Textyles : Revue des Lettres Belges de Langue Française (2005), 26-27

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See detailStudy by Hall probe mapping of the trapped flux modification produced by local heating in YBCOHTS bulks for different surface/volume ratios
Laurent, Philippe ULg; Mathieu, Jean-Philippe; Mattivi, Brice et al

in Superconductor Science and Technology (2005), 18(8), 1047-1053

The aim of this report is to compare the trapped field distribution under a local heating created at the sample edge for different sample morphologies. Hall probe mappings of the magnetic induction ... [more ▼]

The aim of this report is to compare the trapped field distribution under a local heating created at the sample edge for different sample morphologies. Hall probe mappings of the magnetic induction trapped in YBCO bulk samples maintained out of thermal equilibrium were performed on YBCO bulk single domains, YBCO single domains with regularly spaced hole arrays, and YBCO superconducting foams. The capability of heat draining was quantified by two criteria: the average induction (B) decay and the size of the thermally affected zone caused by a local heating of the sample. Among the three investigated sample shapes, the drilled single domain displays a trapped induction which is weakly affected by the local heating while displaying a high trapped field. Finally, a simple numerical modelling of the heat flux spreading into a drilled sample is used to suggest some design rules about the hole configuration and their size. [less ▲]

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See detailRandom matrix models for chiral and diquark condensation
Vanderheyden, Benoît ULg; Jackson, A. D.; Lansberg, Jean-Philippe ULg et al

in AIP Conference Proceedings (2005), 775

We consider random matrix models for the thermodynamic competition between chiral symmetry breaking and diquark condensation in QCD at finite temperature and finite baryon density. The models produce mean ... [more ▼]

We consider random matrix models for the thermodynamic competition between chiral symmetry breaking and diquark condensation in QCD at finite temperature and finite baryon density. The models produce mean field phase diagrams whose topology depends solely on the global symmetries of the theory. We discuss the block structure of the interactions that is imposed by chiral, spin, and color degrees of freedom and comment on the treatment of density and temperature effects. Extension of the coupling parameters to a larger class of theories allows us to investigate the robustness of the phase topology with respect to variations in the dynamics of the interactions. We briefly study the phase structure as a function of coupling parameters and the number of colors. [less ▲]

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See detailExtended-spectrum-beta-lactamase-producing Enterobacteriaceae in Yaounde, Cameroon
Gangoue Pieboji, Joseph ULg; Bedenic, B.; Koulla-Shiro, S. et al

in Journal of Clinical Microbiology (2005), 43(7), 3273-7

Organisms producing extended-spectrum beta-lactamases (ESBLs) have been reported in many countries, but there is no information on the prevalence of ESBL-producing members of the family Enterobacteriaceae ... [more ▼]

Organisms producing extended-spectrum beta-lactamases (ESBLs) have been reported in many countries, but there is no information on the prevalence of ESBL-producing members of the family Enterobacteriaceae in Cameroon. A total of 259 Enterobacteriaceae strains were isolated between 1995 and 1998 from patients at the Yaounde Central Hospital in Cameroon. Enterobacterial isolates resistant to extended-spectrum cephalosporin and monobactam were screened for ESBL production by the double-disk (DD) synergy test. Thirty-one (12%) of these Enterobacteriaceae strains were shown to be positive by the DD synergy test, suggesting the presence of ESBLs. Resistance to oxyimino-cephalosporins and monobactams of 12 (38.7%) of the 31 strains-i.e., 6 Klebsiella pneumoniae, 4 Escherichia coli, 1 Citrobacter freundii, and 1 Enterobacter cloacae strain-was transferred to E. coli HK-225 by conjugation. Resistance to gentamicin, gentamicin plus trimethoprim-sulfamethoxazole, or trimethoprim-sulfamethoxazole was cotransferred into 6, 2, and 1 of these transconjugants, respectively. All 12 transconjugants were resistant to amoxicillin, piperacillin, all of the cephalosporins, and aztreonam but remained susceptible to cefoxitin and imipenem. Crude extracts of beta-lactamase-producing transconjugants were able to reduce the diameters of inhibition zones around disks containing penicillins, narrow- to expanded-spectrum cephalosporins or monobactams when tested against a fully susceptible E. coli strain but had no effect on such zones around cefoxitin, imipenem, and amoxicillin-clavulanate disks. The beta-lactamases produced by the 12 tranconjugants turned out to be SHV-12 by DNA sequencing. Therefore, the ESBL SHV-12 is described for the first time in Cameroon. [less ▲]

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See detailEmergence of CTX-M-15-producing enterobacteria in Cameroon and characterization of a blaCTX-M-15-carrying element
Gangoue Pieboji, Joseph ULg; Miriagou, V.; Vourli, S. et al

in Antimicrobial Agents and Chemotherapy (2005), 49(1), 441-3

CTX-M-15-producing Klebsiella pneumoniae and Escherichia coli emerged recently in Cameroon. CTX-M-15 was encoded by two different multiresistance plasmids, of which one carried an ISEcp1-bla(CTX-M-15 ... [more ▼]

CTX-M-15-producing Klebsiella pneumoniae and Escherichia coli emerged recently in Cameroon. CTX-M-15 was encoded by two different multiresistance plasmids, of which one carried an ISEcp1-bla(CTX-M-15) element flanked by a 5-bp target site duplication and inserted within a Tn2-derived sequence. A truncated form of this element in the second plasmid was identified. [less ▲]

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See detailThe Pseudomonas aeruginosa pirA gene encodes a second receptor for ferrienterobactin and synthetic catecholate analogues.
Ghysels, Bart ULg; Ochsner, Urs; Mollman, Ute et al

in FEMS microbiology letters (2005), 246(2), 167-74

Actively secreted iron chelating agents termed siderophores play an important role in the virulence and rhizosphere competence of fluorescent pseudomonads, including Pseudomonas aeruginosa which secretes ... [more ▼]

Actively secreted iron chelating agents termed siderophores play an important role in the virulence and rhizosphere competence of fluorescent pseudomonads, including Pseudomonas aeruginosa which secretes a high affinity siderophore, pyoverdine, and the low affinity siderophore, pyochelin. Uptake of the iron-siderophore complexes is an active process that requires specific outer membrane located receptors, which are dependent of the inner membrane-associated protein TonB and two other inner membrane proteins, ExbB and ExbC. P. aeruginosa is also capable of using a remarkable variety of heterologous siderophores as sources of iron, apparently by expressing their cognate receptors. Illustrative of this feature are the 32 (of which 28 putative) siderophore receptor genes observed in the P. aeruginosa PAO1 genome. However, except for a few (pyoverdine, pyochelin, enterobactin), the vast majority of P. aeruginosa siderophore receptor genes still remain to be characterized. Ten synthetic iron chelators of catecholate type stimulated growth of a pyoverdine/pyochelin deficient P. aeruginosa PAO1 mutant under condition of severe iron limitation. Null mutants of the 32 putative TonB-dependent siderophore receptor encoding genes engineered in the same genetic background were screened for obvious deficiencies in uptake of the synthetic siderophores, but none showed decreased growth stimulation in the presence of the different siderophores. However, a double knock-out mutant of ferrienterobactin receptor encoding gene pfeA (PA 2688) and pirA (PA0931) failed to be stimulated by 4 of the tested synthetic catecholate siderophores whose chemical structures resemble enterobactin. Ferric-enterobactin also failed to stimulate growth of the double pfeA-pirA mutant although, like its synthetic analogues, it stimulated growth of the corresponding single mutants. Hence, we confirmed that pirA represents a second P. aeruginosa ferric-enterobactin receptor. The example of these two enterobactin receptors probably illustrates a more general phenomenon of siderophore receptor redundancy in P. aeruginosa. [less ▲]

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See detailAdherence to first-line antiretroviral regimens in Rwanda.
Demeester, Remy; Omes, Christine; Karasi, Jean Claude ULg et al

in Journal of Acquired Immune Deficiency Syndromes [=JAIDS] (2005), 40(1), 113-4

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