Browsing
     by title


0-9 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

or enter first few letters:   
OK
Full Text
See detailCharacterization of the K2-19 Multiple-Transiting Planetary System via High-Dispersion Spectroscopy, AO Imaging, and Transit Timing Variations
Narita, Norio; Hirano, Teruyuki; Fukui, Akihiko et al

E-print/Working paper (2015)

K2-19 (EPIC201505350) is an interesting planetary system in which two transiting planets with radii ~ 7 $R_{Earth}$ (inner planet b) and ~ 4 $R_{Earth}$ (outer planet c) have orbits that are nearly in a 3 ... [more ▼]

K2-19 (EPIC201505350) is an interesting planetary system in which two transiting planets with radii ~ 7 $R_{Earth}$ (inner planet b) and ~ 4 $R_{Earth}$ (outer planet c) have orbits that are nearly in a 3:2 mean-motion resonance. Here, we present results of ground-based follow-up observations for the K2-19 planetary system. We have performed high-dispersion spectroscopy and high-contrast adaptive-optics imaging of the host star with the HDS and HiCIAO on the Subaru 8.2m telescope. We find that the host star is relatively old (>8 Gyr) late G-type star ($T_{eff}$ ~ 5350 K, $M_s$ ~ 0.9 $M_{Sun}$, and $R_{s}$ ~ 0.9 $R_{Sun}$). We do not find any contaminating faint objects near the host star which could be responsible for (or dilute) the transit signals. We have also conducted transit follow-up photometry for the inner planet with KeplerCam on the FLWO 1.2m telescope, TRAPPISTCAM on the TRAPPIST 0.6m telescope, and MuSCAT on the OAO 1.88m telescope. We confirm the presence of transit-timing variations, as previously reported by Armstrong and coworkers. We model the observed transit-timing variations of the inner planet using the synodic chopping formulae given by Deck & Agol (2015). We find two statistically indistinguishable solutions for which the period ratios ($P_{c}/P_{b}$) are located slightly above and below the exact 3:2 commensurability. Despite the degeneracy, we derive the orbital period of the inner planet $P_b$ ~ 7.921 days and the mass of the outer planet $M_c$ ~ 20 $M_{Earth}$. Additional transit photometry (especially for the outer planet) as well as precise radial-velocity measurements would be helpful to break the degeneracy and to determine the mass of the inner planet. [less ▲]

Detailed reference viewed: 23 (2 ULg)
Full Text
Peer Reviewed
See detailCharacterization Of The Lipid-Binding Properties And Lipoprotein Lipase Inhibition Of A Novel Apolipoprotein C-Iii Variant Ala23thr
Liu, Hq.; Labeur, C.; Xu, Cf. et al

in Journal of Lipid Research (2000), 41(11), 9201-12

The physicochemical properties of recombinant wild type and three site-directed mutants of apolipoprotein C-III (apoC-III), designed by molecular modeling to alter specific amino acid residues implicated ... [more ▼]

The physicochemical properties of recombinant wild type and three site-directed mutants of apolipoprotein C-III (apoC-III), designed by molecular modeling to alter specific amino acid residues implicated in lipid binding (L9T/T20L, F64A/W65A) or LPL inhibition (K21A), were compared. Relative lipid binding efficiencies to dimyristoylphosphatidylcholine (DMPC) were L9T/T20L > WT >K21A > F64A/W65A with an inverse correlation with size of the discoidal complexes formed. Physicochemical analysis (Trp fluorescence, circular dichroism, and GdnHCl denaturation) suggests that L9T/T20L forms tighter and more stable lipid complexes with phospholipids, while F64A/W65A associates less tightly. Lipid displacement properties were tested by gel-filtrating apoE:dipalmitoylphosphatidylcholine (DPPC) discoidal complexes mixed with the various apoC-III variants. All apoC-III proteins bound to the apoE:DPPC complexes; the amount of apoE displaced from the complex was dependent on the apoC-III lipid binding affinity. All apoC-III proteins inhibited LPL in the presence or absence of apoC-II, with F64A/W65A displaying the most inhibition, suggesting that apoC-III inhibition of LPL is independent of lipid binding and therefore of apoC-II displacement. Taken together. these data suggest that the hydrophobic residues F64 and W65 are crucial for the lipid binding properties of apoC-III and that redistribution of the N-terminal helix of apoC-III (L9T/T20L) enhances the stability of the lipid-bound protein, while LPL inhibition by apoC-III is likely to be due to protein:protein interactions. [less ▲]

Detailed reference viewed: 11 (1 ULg)
Full Text
See detailCharacterization of the low-mass companion around HD 142527 with VLT/SINFONI
Christiaens, Valentin ULg; Casassus, Simon; Absil, Olivier ULg et al

Conference (2016, May 19)

The circumstellar disk of the Herbig Fe star HD 142527 is host to several remarkable features in the context of planetary formation, including a warped inner disk, one of the largest annular gaps, a ... [more ▼]

The circumstellar disk of the Herbig Fe star HD 142527 is host to several remarkable features in the context of planetary formation, including a warped inner disk, one of the largest annular gaps, a prominent dust trap and several spiral arms in its outer disk. A low-mass companion, HD 142527 B, was also found orbiting the primary star at only ~10 au, possibly shaping the inclined inner disk (inclined with respect to the outer disk). This study aims to provide a clarifying answer to the question of the true nature of this companion, which could help explaining its true impact on the peculiar geometry of the disk. We observed the source with VLT/SINFONI in H+K band in pupil-tracking mode. Data were then post-processed with several principal component analysis algorithms based on the principle of Angular Differential Imaging. HD 142527 B is re-detected in most of the H+K spectral channels at a signal-to-noise ratio > 3. This re-detection enables us to extract the first medium-resolution spectrum of a low-mass companion at less than 0.1'' from its central star. The best fit to our spectrum was obtained with a BT-SETTL model spectrum corresponding to a temperature of 3400+-50K and a surface gravity log(g)=2.5+-1.0. Using pre-main sequence tracks, this corresponds to an M3 star with a mass, radius and age of M_B ~0.3 M_Sun, R_B ~ 1.1 R_Sun and 3.6 Myr old, respectively. We also suggest that most of the expected circum-secondary material is at a temperature lower than 1000K, hence not emitting in H and K band, but able to explain the excess measured at L- and M-bands. Based on the new values of radius and mass of the companion, we provide a new estimate for the mass accretion rate on HD 142527 B of ~1% of the accretion rate on the primary, consistent with a non-significant detection in the Brackett-gamma line. This result confirms the efficiency of the pupil-tracking mode implemented on VLT/SINFONI for the spectral characterization of faint companions orbiting very close to their star. [less ▲]

Detailed reference viewed: 20 (1 ULg)
Full Text
See detailCharacterization of the magnetic flux propagation in a drilled YBCO single‐crystal during a pulsed‐field excitation
Lousberg, Grégory ULg

Poster (2009, September)

Article associé : Pulsed-field magnetization of drilled bulk high-temperature superconductors: flux front propagation in the volume and on the surface

Detailed reference viewed: 17 (7 ULg)
Full Text
See detailCharacterization of the magnetic properties of a continuously coated YBCO coated conductor cylinder in persistent current mode
Wera, Laurent ULg; Fagnard, Jean-François ULg; Hogan, Kevin ULg et al

Poster (2015, September 09)

YBCO coated conductors are good candidates for magnetic shielding applications because of (i) their high current density and (ii) their lower weight compared to magnetic shields made of bulk HTS materials ... [more ▼]

YBCO coated conductors are good candidates for magnetic shielding applications because of (i) their high current density and (ii) their lower weight compared to magnetic shields made of bulk HTS materials. In particular, an efficient superconducting magnetic shield can be built as an assembly of milled YBCO 2G coated conductor tape sections, or, as in this case, a continuously coated cylinder. The purpose of the present work is to characterize experimentally the DC magnetic properties of a continuous band of YBCO film (about 1 cm width) deposited around a hastelloy cylinder of 6.4 cm in diameter. In particular, we characterize the distribution and the time dependence of the trapped field inside the cylinder due to persistent current loops. We also investigate the magnetic shielding properties at several sweep rates when the applied magnetic field is parallel to the main axis of the cylinder. All measurements are carried out at 77 K. The measurement of the trapped field of the cylinder gives evidence that a persistent current of about 80 A can be induced in the YBCO band. Magnetic shielding measurements show that, thanks to the persistent current flowing in the band, the cylinder is able to attenuate by a factor of 2 the applied magnetic field. These results open interesting perspectives for a further development of magnetic shields made of coated conductor cylinders. We investigate how the shielding performances could be further improved by increasing the number of layers and by increasing the height of the cylinder. The results are compared to a multilayer coated conductor cylinder with joints and to persistent current loops obtained with milled coated conductor tape sections. [less ▲]

Detailed reference viewed: 53 (16 ULg)
Full Text
Peer Reviewed
See detailCharacterization of the Metabolism of Osteoarthritic Chondrocytes Cultured in Alginate Beads
Sanchez, Christelle ULg; Mathy, Marianne ULg; Deberg, Michelle ULg et al

in Osteoarthritis and Cartilage (2002), 10(SA), 34

Detailed reference viewed: 22 (11 ULg)
Full Text
Peer Reviewed
See detailCharacterization of the metabolism of osteoarthritic chondrocytes cultured in alginate beads
Henrotin, Yves ULg; Sanchez, Christelle ULg; Mathy-Hartert, Marianne et al

in Osteoporosis International (2002, November), 13(Suppl. 3), 52

Detailed reference viewed: 25 (6 ULg)
Full Text
Peer Reviewed
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

Detailed reference viewed: 16 (0 ULg)
Full Text
Peer Reviewed
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 ▲]

Detailed reference viewed: 24 (2 ULg)
Full Text
Peer Reviewed
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

Detailed reference viewed: 7 (0 ULg)
Full Text
Peer Reviewed
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 ▲]

Detailed reference viewed: 80 (22 ULg)
Full Text
Peer Reviewed
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 ▲]

Detailed reference viewed: 30 (0 ULg)
Full Text
Peer Reviewed
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),

Detailed reference viewed: 13 (2 ULg)
Full Text
Peer Reviewed
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 ▲]

Detailed reference viewed: 46 (8 ULg)
Full Text
See detailCharacterization of the physical state of spray-dried inulin.
Ronkart, Sébastien; Deroanne, Claude; Paquot, Michel ULg et al

Poster (2007, October 11)

Detailed reference viewed: 19 (4 ULg)
Full Text
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)

Detailed reference viewed: 18 (4 ULg)
Full Text
Peer Reviewed
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 ▲]

Detailed reference viewed: 24 (0 ULg)
Full Text
Peer Reviewed
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 ▲]

Detailed reference viewed: 109 (31 ULg)
Peer Reviewed
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 ▲]

Detailed reference viewed: 7 (0 ULg)