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
Peer Reviewed
See detailCharacterization of the hot Neptune GJ 436 b with Spitzer and ground-based observations
Demory, B*-O; Gillon, Michaël ULg; Barman, T. et al

in Astronomy and Astrophysics (2007), 475

We present Spitzer Space Telescope infrared photometry of a secondary eclipse of the hot Neptune GJ 436 b. The observations were obtained using the 8-mum band of the InfraRed Array Camera (IRAC). The data ... [more ▼]

We present Spitzer Space Telescope infrared photometry of a secondary eclipse of the hot Neptune GJ 436 b. The observations were obtained using the 8-mum band of the InfraRed Array Camera (IRAC). The data spanning the predicted time of secondary eclipse show a clear flux decrement with the expected shape and duration. The observed eclipse depth of 0.58 mmag allows us to estimate a blackbody brightness temperature of T[SUB]p[/SUB] = 717 ± 35 K at 8 mum. We compare this infrared flux measurement to a model of the planetary thermal emission, and show that this model reproduces properly the observed flux decrement. The timing of the secondary eclipse confirms the non-zero orbital eccentricity of the planet, while also increasing its precision (e = 0.14 ± 0.01). Additional new spectroscopic and photometric observations allow us to estimate the rotational period of the star and to assess the potential presence of another planet. Our final secondary eclipse, photometric and Ca II H+K index time series are 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/475/1125 [less ▲]

Detailed reference viewed: 69 (0 ULg)
Full Text
Peer Reviewed
See detailCharacterization of the human Fc gamma RIIB gene promoter: human zinc-finger proteins (ZNF140 and ZNF91) that bind to different regions function as transcription repressors
Nishimura, Tadahiro; Narita, Tadashi; Miyazaki, Emi et al

in International Immunology (2001), 13(8), 1075-84

Expression of the human low-affinity Fc receptors for IgG (human Fc gamma RII) is differentially regulated. We report here the characterization of the promoter structure of the human Fc gamma RIIB gene ... [more ▼]

Expression of the human low-affinity Fc receptors for IgG (human Fc gamma RII) is differentially regulated. We report here the characterization of the promoter structure of the human Fc gamma RIIB gene and the isolation of the promoter region-binding proteins by a yeast one-hybrid assay. The minimal 154-bp region upstream from the transcription start site of the human Fc gamma RIIB gene was shown to possess promoter activity in a variety of cells. An electrophoretic mobility shift assay indicated that multiple nuclear factors in cell extracts bind to the two regions [F2-3 (-110 to -93) and F4-3 (-47 to -31)] of the human Fc gamma RIIB gene promoter. Mutation analysis indicated that GGGAGGAGC (-105 to -97) and AATTTGTTTGCC (-47 to -36) sequences are responsible for binding to nuclear factors respectively. By using GGGAGGAGC and AATTTGTTTGCC as bait sequences, we cloned two zinc-finger proteins (ZNF140 and ZNF91) that bind to the F2-3 and F4-3 regions within the promoter of the human Fc gamma RIIB gene respectively. When the ZNF140 and ZNF91 were transfected with reporter plasmid, both showed repressor activity with additive effects. Thus, these results indicate that these cloned ZNF140 and ZNF91 proteins function as repressors for the human Fc gamma RIIB transcription. [less ▲]

Detailed reference viewed: 45 (3 ULg)
Full Text
Peer Reviewed
See detailCharacterization of the IGF system and analysis of the possible molecular mechanisms leading to IGF-II overexpression in a mesothelioma.
Hodzic, D.; Delacroix, Laurence ULg; Willemsen, P. et al

in Hormone & Metabolic Research (1997), 29(11), 549-55

The expression of members of the IGF system in a mesothelioma from a patient suffering from hypoglycemia, in term placenta and HT29 colon adenocarcinoma cells were compared. Very high levels of IGF-II ... [more ▼]

The expression of members of the IGF system in a mesothelioma from a patient suffering from hypoglycemia, in term placenta and HT29 colon adenocarcinoma cells were compared. Very high levels of IGF-II mRNA and protein were detected in the mesothelioma. Moreover, half of the IGF-II protein took the high-molecular-weight form. We also analyzed the parental imprinting status and the promoter usage of the IGF-II gene. Our results showed loss of imprinting (LOI) in the mesothelioma while the imprinting was maintained in HT29 cells, expressing moderate levels of the transcript. Promoter P4 was active in the three tissues we analyzed, whereas IGF-II mRNA transcription from promoter P3 was only detected in the mesothelioma and the placenta, expressing comparably high levels of the transcript. IGF-II gene structure was identical in the analyzed tissues and cells. The type-I receptor mRNA expression was very low in the tumor. IGFBP-2, -4 and -5 mRNAs were detected in the mesothelioma, while IGFBP-2, -3 and -5 transcripts were detected in the placenta. IGFBP-1 and -6 transcripts were not detected. [less ▲]

Detailed reference viewed: 17 (0 ULg)
Full Text
See detailCharacterization of the impact of tillage and nitrogen fertilization on the root development of a winter wheat crop by use of NIR hyperspectral imaging combined to chemometrics
Fraipont, Guillaume ULg; Eylenbosch, Damien ULg; Fernández Pierna, Juan Antonio et al

Poster (2016, March 16)

The objective of this study is to characterize the impact of tillage management and nitrogen fertilization on the root system development of a winter wheat crop. To reach this objective, an innovative ... [more ▼]

The objective of this study is to characterize the impact of tillage management and nitrogen fertilization on the root system development of a winter wheat crop. To reach this objective, an innovative root quantification method that combines NIR hyperspectral imaging (NIR-HSI) and chemometric tools will be applied. [less ▲]

Detailed reference viewed: 50 (16 ULg)
Full Text
See detailCharacterization of the impact of tillage on the root development and distribution of crop residues of a winter wheat crop by the use of NIR hyperspectral imaging
Fraipont, Guillaume ULg; Eylenbosch, Damien ULg; Fernández Pierna, Juan Antonio et al

Poster (2016, May 20)

The objectives of the study were to show the impact of tillage and crop residues management on the distribution of crop residues and root system of a winter wheat crop in the 0-30 cm soil profile.This ... [more ▼]

The objectives of the study were to show the impact of tillage and crop residues management on the distribution of crop residues and root system of a winter wheat crop in the 0-30 cm soil profile.This poster shows the results obtained during one crop year (2011-2012). This study is allowed by a rapid and innovative method of root system quantification based on the near infrared hyperspectral Imaging. [less ▲]

Detailed reference viewed: 38 (13 ULg)
Peer Reviewed
See detailCharacterization of the insulin-like growth (IGF) axis in the human thymus
Kecha, Ouafae; Achour, Imane; Martens, Henri ULg et al

in The Endocrine Society (Ed.) Proceedings of the 77th Annual Meeting of the Endocrine Society (1997)

Detailed reference viewed: 6 (0 ULg)
Full Text
Peer Reviewed
See detailCharacterization of the Insulin-Like Growth Factor Axis in the Human Thymus
Kecha, Ouafae; Martens, Henri ULg; Franchimont, Nathalie et al

in Journal of Neuroendocrinology (1999), 11(6), 435-40

The components of the insulin-like growth factor (IGF) axis have been investigated in the normal human thymus. Using ribonuclease protection assays (RPA), IGF-II transcripts were detected in the normal ... [more ▼]

The components of the insulin-like growth factor (IGF) axis have been investigated in the normal human thymus. Using ribonuclease protection assays (RPA), IGF-II transcripts were detected in the normal human thymus. By reverse transcriptase polymerase chain reaction (RT-PCR) analyses, promoters P3 and P4 were found to be active in the transcription of IGF2 gene within human thymic epithelial cells (TEC). No IGF-II mRNA could be detected in human lymphoid Jurkat T cells with 30 cycles of RT-PCR. By Northern blot analyses, IGFBP-2 to -6 (but not IGFBP-1) were found to be expressed in TEC with a predominance of IGFBP-4. Interestingly, Jurkat T cells only express IGFBP-2 but at high levels. The type 1 IGF receptor was detected in Jurkat T cells but not in human TEC. The identification of the components of the IGF axis within separate compartments of the human thymus adds further evidence for a role of this axis in the control of T-cell development. The precise influence of thymic IGF axis upon T-cell differentiation and immunological self-tolerance however needs to be further investigated. [less ▲]

Detailed reference viewed: 33 (0 ULg)
Full Text
Peer Reviewed
See detailCharacterization of the interaction between nanoformulated drugs and model lipid membranes towards improved drug delivery systems
De Battice, Laura; Frost, Rickard; Sevrin, Chantal ULg et al

Poster (2011, October)

Detailed reference viewed: 6 (0 ULg)
Full Text
See detailCharacterization of the interaction between nanoformulated drugs and model lipid membranes towards improved drug delivery systems
De Battice, Laura; Frost, Rickard; Sevrin, Chantal ULg et al

Poster (2011, October 25)

Detailed reference viewed: 4 (0 ULg)
Peer Reviewed
See detailCharacterization of the interaction of xylose-based bolaamphiphiles with biomimetic membrane systems
Nasir, Mehmet Nail ULg; Legrand, Vincent; Gatard, Sylvain et al

Conference (2012, July)

Detailed reference viewed: 24 (4 ULg)
Full Text
Peer Reviewed
See detailCharacterization of the interactions between fluoroquinolone antibiotics and lipids: a multitechnique approach.
Bensikaddour, Hayet; Fa, Nathalie; Burton, Ingrid et al

in Biophysical Journal (2008), 94(8), 3035-46

Probing drug/lipid interactions at the molecular level represents an important challenge in pharmaceutical research and membrane biophysics. Previous studies showed differences in accumulation and ... [more ▼]

Probing drug/lipid interactions at the molecular level represents an important challenge in pharmaceutical research and membrane biophysics. Previous studies showed differences in accumulation and intracellular activity between two fluoroquinolones, ciprofloxacin and moxifloxacin, that may actually result from their differential susceptibility to efflux by the ciprofloxacin transporter. In view of the critical role of lipids for the drug cellular uptake and differences observed for the two closely related fluoroquinolones, we investigated the interactions of these two antibiotics with lipids, using an array of complementary techniques. Moxifloxacin induced, to a greater extent than ciprofloxacin, an erosion of the DPPC domains in the DOPC fluid phase (atomic force microscopy) and a shift of the surface pressure-area isotherms of DOPC/DPPC/fluoroquinolone monolayer toward lower area per molecule (Langmuir studies). These effects are related to a lower propensity of moxifloxacin to be released from lipid to aqueous phase (determined by phase transfer studies and conformational analysis) and a marked decrease of all-trans conformation of acyl-lipid chains of DPPC (determined by ATR-FTIR) without increase of lipid disorder and change in the tilt between the normal and the germanium surface (also determined by ATR-FTIR). All together, differences of ciprofloxacin as compared to moxifloxacin in their interactions with lipids could explain differences in their cellular accumulation and susceptibility to efflux transporters. [less ▲]

Detailed reference viewed: 54 (2 ULg)
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: 24 (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: 13 (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: 22 (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: 18 (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: 54 (16 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)