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See detailNew mutations in ADC-type beta-lactamases from Acinetobacter spp. affect cefoxitin and ceftazidime hydrolysis.
Perez, Astrid; Perez-Llarena, Francisco Jose; Garcia, Patricia et al

in The Journal of antimicrobial chemotherapy (2014)

OBJECTIVES: Two natural variants of ADC-type beta-lactamases of Acinetobacter spp., ADC-1 and ADC-5, differ by nine mutations in their protein sequence. ADC-5 hydrolyses cefoxitin better than ADC-1 and ... [more ▼]

OBJECTIVES: Two natural variants of ADC-type beta-lactamases of Acinetobacter spp., ADC-1 and ADC-5, differ by nine mutations in their protein sequence. ADC-5 hydrolyses cefoxitin better than ADC-1 and the opposite is true for ceftazidime. We produced single and combined mutations in ADC-5 and characterized the variants microbiologically and biochemically to determine which amino acid residues are involved in the hydrolysis of beta-lactam antibiotics in this family of beta-lactamases. METHODS: Site-directed mutagenesis, with blaADC-5 as a source of DNA, was used to generate nine single mutated and three combined mutated enzymes. The proteins (wild-type and derivatives) were then expressed in isogenic conditions in Escherichia coli. MICs of beta-lactams were determined using Etest strips. ADC-1, ADC-5, ADC-5-P167S and ADC-5-P167S/D242G/Q163K/G342R were also purified and the kinetic parameters determined for ceftazidime, cefoxitin, cefalotin and ampicillin. RESULTS: Single mutations did not significantly convert the hydrolysis spectrum of the ADC-5 enzyme into that of the ADC-1 enzyme, although among all studied mutants only the quadruple mutant (ADC-5-P167S/D242G/Q163K/G342R) displayed microbiological and biochemical properties consistent with those of ADC-1. CONCLUSIONS: Although some single mutations are known to affect cefepime hydrolysis in ADC-type beta-lactamases, little is known about ceftazidime and cefoxitin hydrolysis in this family of beta-lactamases. Hydrolysis of these antibiotics appears to be positively and negatively affected, respectively, by the Q163K, P167S, D242G and G342R amino acid replacements. [less ▲]

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See detailNew nanocomposite materials based on plasticized poly(L-lactide) and organo-modified montmorillonites: thermal and morphological study
Paul, Marie-Amélie; Degée, Philippe; Henrist, Catherine ULg et al

in Polymer (2003), 44(2), 443-450

Plasticized poly(L-lactide) (PLA) based nanocomposites were prepared by melt blending of the matrix with 20 wt% of poly(ethyleneglycol) 1000 (PEG 1000) and different amounts of montmorillonite, organo ... [more ▼]

Plasticized poly(L-lactide) (PLA) based nanocomposites were prepared by melt blending of the matrix with 20 wt% of poly(ethyleneglycol) 1000 (PEG 1000) and different amounts of montmorillonite, organo-modified or not. The intercalation of the polymer chains between the aluminosilicates layers and morphological structure of the filled PLAs were analysed by wide-angle X-ray scattering (WAXS). Thermogravimetric analyses (TGA) and differential scanning calorimetry (DSC) were performed to study the thermal behaviour of the prepared composites. At constant filler level, it appears that from all the clays studied, the montmorillonite organo-modified by bis-(2-hydroxyethyl)methyl (hydrogenated tallowalkyl) ammonium cations brings the greater effect in terms of thermal stability. Increasing the amount of clay allows to delay the onset of thermal degradation of the plasticized polymer matrix. It was also pointed out, by WAXS and DSC analyses, that it exists a real competition between PEG 1000 and PLA for the intercalation into the interlayer spacing of the clay. (C) 2002 Elsevier Science Ltd. All rights reserved. [less ▲]

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See detailNew nanostructured materials based on fullerene and biodegradable polyesters
Stoilova, Olya; Jérôme, Christine ULg; Detrembleur, Christophe ULg et al

in Chemistry of Materials (2006), 18(20), 4917-4923

Star-shaped poly(epsilon-caprolactone) (PCL) with a fullerene (C-60) core, C-60[N(CH2)(12)OPCLOH](x), was successfully synthesized by reaction of azide-terminated PCL with C-60. Both the experimental ... [more ▼]

Star-shaped poly(epsilon-caprolactone) (PCL) with a fullerene (C-60) core, C-60[N(CH2)(12)OPCLOH](x), was successfully synthesized by reaction of azide-terminated PCL with C-60. Both the experimental conditions and the stoichiometry were optimized, such that an average of six PCL chains was grafted per fullerene core. The molecular weight of the polyester chains directly controlled the length of the arms of the star-shaped polymers. Singlet oxygen was generated on irradiation of the C-60[N(CH2)(12)OPCLOH] x nanohybrids. These C-60[N(CH2)(12)OPCLOH](x) nanohybrids were then processed in two kinds of nanomaterials. First, they were encapsulated within the core of micelles formed by biocompatible amphiphilic block copolymers. In water, the particle size distribution of these nanoparticles was narrow, and their diameter was in the range of 100 to 200 nm. Second, C-60-containing micro-/nanosized polymer fibers were prepared, for the first time, by electrospinning. The average diameter of the fibers was varied by tuning the PCL/C-60[N(CH2)(12)OPCLOH](x) weight ratio. Grafting of polyester chains onto C-60 is thus a suitable strategy for producing easily processable C-60 and attractive building blocks for incorporation of C-60 in nanomaterials. [less ▲]

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See detailNew national and regional bryophyte records, 12
Blockeel, T. L.; Chlebicko, A.; Hajkova, P. et al

in Journal of Bryology (2006), 28(1), 68-70

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See detailA new natural hGH variant--17.5 kd--produced by alternative splicing. An additional consensus sequence which might play a role in branchpoint selection
Lecomte, C. M.; Renard, A.; Martial, Joseph ULg

in Nucleic Acids Research (1987), 15(16), 6331-48

From a human pituitary cDNA library, we have cloned 3 distinct human growth hormone (hGH) cDNAs, coding respectively for the 22 K hGH, the 20 K variant, and a yet unknown 17.5 K variant. S1 mapping ... [more ▼]

From a human pituitary cDNA library, we have cloned 3 distinct human growth hormone (hGH) cDNAs, coding respectively for the 22 K hGH, the 20 K variant, and a yet unknown 17.5 K variant. S1 mapping analysis using human pituitary RNA confirms the existence of at least four distinct hGH mRNAs originating from alternative acceptor sites at the second intron of the primary transcript. We have analysed the hGH gene sequence to explain the high frequency of alternative splicings which occur only at this location. In this study we propose CTTGNNPyPyPy as an additional consensus sequence guiding the selection of the branched nucleotide. [less ▲]

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See detailNew Non-Overlapping Domain Decomposition Algorithm for the Helmholtz Equation
Boubendir, Y.; Antoine, X.; Geuzaine, Christophe ULg

in Proceedings of the 20th International Conference on Domain Decomposition Methods (DD20) (2011, February)

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See detailNew noncovalent inhibitors of penicillin-binding proteins from penicillin-resistant bacteria.
Turk, Samo; Verlaine, Olivier ULg; Gerards, Thomas ULg et al

in PloS one (2011), 6(5), 19418

BACKGROUND: Penicillin-binding proteins (PBPs) are well known and validated targets for antibacterial therapy. The most important clinically used inhibitors of PBPs beta-lactams inhibit transpeptidase ... [more ▼]

BACKGROUND: Penicillin-binding proteins (PBPs) are well known and validated targets for antibacterial therapy. The most important clinically used inhibitors of PBPs beta-lactams inhibit transpeptidase activity of PBPs by forming a covalent penicilloyl-enzyme complex that blocks the normal transpeptidation reaction; this finally results in bacterial death. In some resistant bacteria the resistance is acquired by active-site distortion of PBPs, which lowers their acylation efficiency for beta-lactams. To address this problem we focused our attention to discovery of novel noncovalent inhibitors of PBPs. METHODOLOGY/PRINCIPAL FINDINGS: Our in-house bank of compounds was screened for inhibition of three PBPs from resistant bacteria: PBP2a from Methicillin-resistant Staphylococcus aureus (MRSA), PBP2x from Streptococcus pneumoniae strain 5204, and PBP5fm from Enterococcus faecium strain D63r. Initial hit inhibitor obtained by screening was then used as a starting point for computational similarity searching for structurally related compounds and several new noncovalent inhibitors were discovered. Two compounds had promising inhibitory activities of both PBP2a and PBP2x 5204, and good in-vitro antibacterial activities against a panel of Gram-positive bacterial strains. CONCLUSIONS: We found new noncovalent inhibitors of PBPs which represent important starting points for development of more potent inhibitors of PBPs that can target penicillin-resistant bacteria. [less ▲]

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See detailNew norovirus classified as a recombinant GII.g/GII.1 causes an extended foodborne outbreak at a university hospital in Munich
Hoffman, Dieter; Mauroy, Axel ULg; Seebach, Judith et al

in Journal of Clinical Virology (2013), (58), 24-30

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See detailNew observational results on the colliding wind WR+O binary WR 30a
Gosset, Eric ULg; Royer, P.; Rauw, Grégor ULg et al

in Wolf-Rayet Phenomena in Massive Stars and Starburst Galaxies (1999)

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See detailNew observations and gravitational lens models of the Cloverleaf quasar H1413 + 117
Kayser, R.; Surdej, Jean ULg; Condon, J. J. et al

in Astrophysical Journal (1990), 364

New optical and radio observations of the quadruple quasar H1413 + 117, the Cloverleaf, are presented. VLA data show radio counterparts at the positions of the four optical images and an additional strong ... [more ▼]

New optical and radio observations of the quadruple quasar H1413 + 117, the Cloverleaf, are presented. VLA data show radio counterparts at the positions of the four optical images and an additional strong radio source between images B and D. Gravitational lens models of H1413 + 117 using (1) a single elliptical galaxy and (2) two spherical galaxies are presented, which fit the positions of the four images of the quasar remarkably well. The models suggest that the strong radio source is a feature of the quasar, e.g., an ejected blob, which lies right on the caustic of the lens and is thereby strongly amplified. The time delays predicted by these models are sufficiently short to allow for their determination within one observational season, making H1413 + 117 an exceptionally well suited object for gravitational lens research. [less ▲]

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See detailNew observations on some Upper Devonian brachiopods from the Namur-Dinant Basin (Belgium)
Mottequin, Bernard ULg

in Geodiversitas (2008), 30

Brachiopods (Productida [except Chonetidina], Orthida, Athyridida, Spiriferida [Adolfiidae, Reticulariidae, Ambocoeliidae, Thomasariidae], and Spiriferinida) recovered in the interval, in terms of the ... [more ▼]

Brachiopods (Productida [except Chonetidina], Orthida, Athyridida, Spiriferida [Adolfiidae, Reticulariidae, Ambocoeliidae, Thomasariidae], and Spiriferinida) recovered in the interval, in terms of the standard conodont zonation, between the Palmatolepis hassi and P. triangularis zones (Late Middle Frasnian to Early Famennian) in the Namur-Dinant Basin (Belgium) are described. The orders and suborders investigated include 32 species: 21 are described in open nomenclature, seven are previously known, four are new of which three are assigned to previously known genera: Aulacella aggeris n. sp., Dicamara plutonis n. sp., and Warrenella (Warrenella) aquaealbae n. sp. Th e fourth species belonging to a newly defined genus: Neptunathyris buxi n. gen., n. sp. A major brachiopod faunal change occurs at the top of the P. rhenana Zone in southern Belgium, with the disappearance of most existing species in parallel with the deterioration of the oxygenation conditions preceding the Upper Kelwasser Event. Only an impoverished fauna (Lingulida, Chonetidina, Rhynchonellida) has been collected in the P. linguiformis Zone. The recovery of the Famennian brachiopods after the end-Frasnian biotic crisis was rapid in the basal Famennian but, despite their great abundance, their diversity was relatively low. New cosmopolitan genera appeared at this time especially among the rhynchonellids, athyridids and spiriferids with new species of pre-existing orthid and orthotetid genera. [less ▲]

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See detailA new observed pre-copulatory behaviour of the lesser-spotted dogfish, scyliorhinus canicula, in captivity
Domi, Nadège; Poncin, Pascal ULg; Voss, Jacques

in Société française d'Ichtyologie (1999)

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See detailA new oil-based formulation of Trichoderma asperellum for the biological control of cacao black pod disease caused by Phytophthora megakarya
Mbarga, J.B.; Begoude, B.A.D.; Ambang, Z. et al

in Biological Control (2014), 77

In African cacao-producing countries, control of cacao black pod disease caused by hytophthora megakarya is a priority. Introducing biological control agents as part of a P. megakarya control strategy is ... [more ▼]

In African cacao-producing countries, control of cacao black pod disease caused by hytophthora megakarya is a priority. Introducing biological control agents as part of a P. megakarya control strategy is highly desirable, especially in a perspective of pesticide reduction. Trichoderma species are among the most used biological control agents. In Cameroon, Trichoderma asperellum formulated in wettable powder has produced positive effects against this disease. However, with this type of formulation, shelf-life and persistence of conidia on pods are limited. Our study therefore sought to develop a new T. asperellum formulation that would be more effective and better suited to the conditions of field application by small-scale producers in Cameroon. We selected a soybean oil-based oil dispersion, in which the half-life of the conidia reached 22.5 weeks, versus 5 weeks in aqueous suspension. Tested on detached pods, the formulation completely inhibited the development of the disease. When sprayed in the field on cacao clones highly sensitive to P. megakarya, the formulation resulted in 90% protection of treated pods after 1 week, and 50% after 3.2 weeks. The formulations exercised a measurable effect for up to 7 weeks, versus 2 weeks in the case of an aqueous conidial suspension and 5 weeks for that of a conventional fungicide (Kocide). Trichoderma asperellum formulated in oil dispersion has therefore great potential for the control of cacao black pod disease with less recourse to synthetic fungicides. [less ▲]

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See detailNew Ophthalmosaurid Ichthyosaurs from the European Lower Cretaceous Demonstrate Extensive Ichthyosaur Survival across the Jurassic–Cretaceous Boundary
Fischer, Valentin ULg; Maisch, Michael; Naish, Darren et al

in PLoS ONE (2012), 7(1), 29234

Background Ichthyosauria is a diverse clade of marine amniotes that spanned most of the Mesozoic. Until recently, most authors interpreted the fossil record as showing that three major extinction events ... [more ▼]

Background Ichthyosauria is a diverse clade of marine amniotes that spanned most of the Mesozoic. Until recently, most authors interpreted the fossil record as showing that three major extinction events affected this group during its history: one during the latest Triassic, one at the Jurassic–Cretaceous boundary (JCB), and one (resulting in total extinction) at the Cenomanian-Turonian boundary. The JCB was believed to eradicate most of the peculiar morphotypes found in the Late Jurassic, in favor of apparently less specialized forms in the Cretaceous. However, the record of ichthyosaurs from the Berriasian–Barremian interval is extremely limited, and the effects of the end-Jurassic extinction event on ichthyosaurs remains poorly understood. Methodology/Principal Findings Based on new material from the Hauterivian of England and Germany and on abundant material from the Cambridge Greensand Formation, we name a new ophthalmosaurid, Acamptonectes densus gen. et sp. nov. This taxon shares numerous features with Ophthalmosaurus, a genus now restricted to the Callovian–Berriasian interval. Our phylogenetic analysis indicates that Ophthalmosauridae diverged early in its history into two markedly distinct clades, Ophthalmosaurinae and Platypterygiinae, both of which cross the JCB and persist to the late Albian at least. To evaluate the effect of the JCB extinction event on ichthyosaurs, we calculated cladogenesis, extinction, and survival rates for each stage of the Oxfordian–Barremian interval, under different scenarios. The extinction rate during the JCB never surpasses the background extinction rate for the Oxfordian–Barremian interval and the JCB records one of the highest survival rates of the interval. Conclusions/Significance There is currently no evidence that ichthyosaurs were affected by the JCB extinction event, in contrast to many other marine groups. Ophthalmosaurid ichthyosaurs remained diverse from their rapid radiation in the Middle Jurassic to their total extinction at the beginning of the Late Cretaceous. [less ▲]

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See detailNew ophthalmosaurids from Europe and Russia broaden the biodiversity of Early Cretaceous ichthyosaurs
Fischer, Valentin ULg

Poster (2011, November)

Ophthalmosauridae is a successful clade of ichthyosaurs that rapidly diversified during the Middle Jurassic. By Late Jurassic, Ophthalmosauridae were diverse, widespread, and formed an important component ... [more ▼]

Ophthalmosauridae is a successful clade of ichthyosaurs that rapidly diversified during the Middle Jurassic. By Late Jurassic, Ophthalmosauridae were diverse, widespread, and formed an important component of the marine trophic webs. By contrast, the record of Berriasian- Aptian ichthyosaurs is extremely poor, and all ichthyosaurs from that interval have been referred to a single genus, Platypterygius, until recently. This apparent diversity drop led numerous authors to recognize a severe ichthyosaur extinction at the end of the Jurassic that left ichthyosaurs as a small group on the decline. New specimens from poorly sampled time periods (late Valanginian, late Hauterivian and late Barremian) in Europe and Russia contradict this latest Jurassic extinction hypothesis and show that new and highly derived as well as typically ‘Late Jurassic’ ichthyosaurs roamed the Eurasian archipelago during the Early Cretaceous. Moreover, these new forms occupied ecological niches markedly different from that of Platypterygius, significantly broadening the disparity and ecological diversity of Cretaceous ichthyosaurs [less ▲]

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See detailNew optical polarization measurements of quasi-stellar objects. The data
Sluse, D.; Hutsemekers, Damien ULg; Lamy, H. et al

in Astronomy and Astrophysics (2005), 433

New linear polarization measurements (mainly in the V band) are presented for 203 quasi-stellar objects (QSOs). The sample is made up of 94 QSOs located in the North Galactic Pole (NGP) region and of 109 ... [more ▼]

New linear polarization measurements (mainly in the V band) are presented for 203 quasi-stellar objects (QSOs). The sample is made up of 94 QSOs located in the North Galactic Pole (NGP) region and of 109 QSOs in the South Galactic Pole (SGP) region. First time measurements have been obtained for 184 QSOs. Among them, 109 known radio-emitters, 42 known Broad Absorption Line (BAL) QSOs, and 1 gravitationally lensed quasi-stellar object. We found high polarization levels (p > 3%) for 12 QSOs, including the BAL QSO <ASTROBJ>SDSS J1409+0048</ASTROBJ>. For 10 objects, measurements obtained at different epochs do exist. Two of them show evidence for variability: the highly polarized BL Lac candidate <ASTROBJ>PKS 1216-010</ASTROBJ> and the radio source <ASTROBJ>PKS 1222+037</ASTROBJ>. Based on observations collected at the European Southern Observatory (ESO, La Silla and Paranal). Table 4 is only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/433/757 [less ▲]

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See detailA new orbital solution for the massive binary system HD 93403
Rauw, Grégor ULg; Sana, H.; Gosset, Eric ULg et al

in Astronomy and Astrophysics (2000), 360

We present a spectroscopic analysis of the early-type massive binary system HD 93403. Using high resolution optical spectra, we clearly separate the primary and secondary components. For the first time ... [more ▼]

We present a spectroscopic analysis of the early-type massive binary system HD 93403. Using high resolution optical spectra, we clearly separate the primary and secondary components. For the first time, we are able to provide an orbital solution for both stars. Our new orbital parameters show discrepancies with the previous solution published by Thackeray & Emerson (?). We further discuss several spectral features of HD 93403. We finally derive qualitative constraints on the inclination of the system and we discuss its evolutionary status and the position of both components in the Hertzsprung-Russell diagram. Based on observations collected at the European Southern Observatory (La Silla, Chile) and the Cerro Tololo Inter-American Observatory (CTIO). [less ▲]

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See detailA new orbital solution for the WNL binary system WR12
Rauw, Grégor ULg; Vreux, Jean-Marie ULg; Gosset, Eric ULg et al

in Liege International Astrophysical Colloquia (1996)

Not Available

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See detailNew Orleans Jazz & Heritage Festival 2014
Sacré, Robert ULg

E-print/Working paper (2014)

Compte rendu du NOLA Jazz & Heritage Festival avril-mai 2014 , avec photos

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