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
See detailHigh color ratio and high temperature in Jupiter's auroral atmosphere
Grodent, Denis ULg; Gustin, Jacques ULg; Gérard, Jean-Claude ULg et al

Poster (2001, October 27)

A high FUV color ratio usually implies that most of the energy of the impinging auroral particles is deposited below the methane homopause. In this region, the resulting auroral heating is efficiently ... [more ▼]

A high FUV color ratio usually implies that most of the energy of the impinging auroral particles is deposited below the methane homopause. In this region, the resulting auroral heating is efficiently balanced by the strong hydrocarbon cooling. Therefore, this auroral process cannot sustain the high temperature observed in the Jovian auroral atmosphere. This work is an attempt to remove the ambiguity between the high color ratios and high temperatures deduced from the HST data. In order to study this apparent contradiction, the two-stream energy deposition model described by Grodent et al. (2001) has been upgraded with a Joule heating module and an adiabatic cooling approximation. The most recent hydrocarbon auroral density profiles have been included. A new EUV-FUV spectral generator has been developed and allows one to consider new observational constrains, such as the very high H2 scale heights deduced from the Cassini-Jupiter flyby HST observations. [less ▲]

Detailed reference viewed: 13 (2 ULg)
Full Text
Peer Reviewed
See detailHigh concentrations of Myeloperoxidase in the equine uterus as an indicator of endometritis
Parrilla Hernandez, Sonia ULg; Ponthier, Jérôme ULg; Franck, Thierry ULg et al

in Theriogenology (in press)

Intra-luminal fluid and excessive abnormal hyper-edema are regularly used for the diagnosis of endometritis in the mare, which is routinely confirmed by the presence of neutrophils on endometrial smears ... [more ▼]

Intra-luminal fluid and excessive abnormal hyper-edema are regularly used for the diagnosis of endometritis in the mare, which is routinely confirmed by the presence of neutrophils on endometrial smears. Studies show a relation between neutrophils and myeloperoxidase (MPO), an enzyme contained in and released by neutrophils during degranulation or after cell lysis. This enzyme has been found in many fluids and tissues and associated with different inflammatory pathologies in the horse. The aims of this study were to assess the presence and concentration of MPO in the equine uterus, and to investigate its relation with neutrophils, and other clinical signs of endometritis. Mares (n=51) were evaluated for presence of intra-luminal fluid and excessive endometrial edema before breeding, and a small volume lavage and cytology samples were obtained. From 69 cycles, supernatant of the uterine flushes was analysed with a specific equine MPO ELISA assay to measure MPO concentration. Cytology samples were used for the diagnosis of endometritis. MPO was present in the uterus of all estrus mares in highly variable concentrations. MPO concentrations were significantly (p<0.05) higher in samples with positive cytologies and in presence of intra-luminal fluid. Occasionally, some samples with negative cytologies showed high MPO concentration, but the opposite was never observed. Cycles presenting hyper-edema weren’t associated to high concentration of MPO, intra-luminal fluid or positive cytology making it a poor diagnostic tool of endometritis. [less ▲]

Detailed reference viewed: 18 (3 ULg)
Full Text
Peer Reviewed
See detailThe high conductivity of iron and thermal evolution of the Earth's core
Gomi, Hitoshi; Ohta, Kenji; Hirose, Kei et al

in Physics of the Earth and Planetary Interiors (2013), 224

Detailed reference viewed: 15 (1 ULg)
See detailHigh contrast stellar observations within the diffraction limit at the Palomar Hale telescope
Mennesson, B.; Hanot, Charles ULg; Serabyn, E. et al

in McLean, I.; Ramsay, S.; Takami, H. (Eds.) Ground-based and Airborne Instrumentation for Astronomy III (2010, July 01)

We report on high-accuracy, high-resolution (< 20mas) stellar measurements obtained in the near infrared ( 2.2 microns) at the Palomar 200 inch telescope using two elliptical (3m x 1.5m) sub-apertures ... [more ▼]

We report on high-accuracy, high-resolution (< 20mas) stellar measurements obtained in the near infrared ( 2.2 microns) at the Palomar 200 inch telescope using two elliptical (3m x 1.5m) sub-apertures located 3.4m apart. Our interferometric coronagraph, known as the "Palomar Fiber Nuller" (PFN), is located downstream of the Palomar adaptive optics (AO) system and recombines the two separate beams into a common singlemode fiber. The AO system acts as a "fringe tracker", maintaining the optical path difference (OPD) between the beams around an adjustable value, which is set to the central dark interference fringe. AO correction ensures high efficiency and stable injection of the beams into the single-mode fiber. A chopper wheel and a fast photometer are used to record short (< 50ms per beam) interleaved sequences of background, individual beam and interferometric signals. In order to analyze these chopped null data sequences, we developed a new statistical method, baptized "Null Self-Calibration" (NSC), which provides astrophysical null measurements at the 0.001 level, with 1 σ uncertainties as low as 0.0003. Such accuracy translates into a dynamic range greater than 1000:1 within the diffraction limit, demonstrating that the approach effectively bridges the traditional gap between regular coronagraphs, limited in angular resolution, and long baseline visibility interferometers, whose dynamic range is restricted to 100:1. As our measurements are extremely sensitive to the brightness distribution very close to the optical axis, we were able to constrain the stellar diameters and amounts of circumstellar emission for a sample of very bright stars. With the improvement expected when the PALM-3000 extreme AO system comes on-line at Palomar, the same instrument now equipped with a state of the art low noise fast read-out near IR camera, will yield 10[SUP]-4[/SUP] to 10[SUP]-3[/SUP] contrast as close as 30 mas for stars with K magnitude brighter than 6. Such a system will provide a unique and ideal tool for the detection of young (<100 Myr) self-luminous planets and hot debris disks in the immediate vicinity (0.1 to a few AUs) of nearby (< 50pc) stars. [less ▲]

Detailed reference viewed: 11 (4 ULg)
Full Text
Peer Reviewed
See detailHigh correlation between the Roche COBAS(R) AmpliPrep/COBAS(R) TaqMan(R) HIV-1, v2.0 and the Abbott m2000 RealTime HIV-1 assays for quantification of viral load in HIV-1 B and non-B subtypes.
Karasi, Jean Claude ULg; Dziezuk, F; Quennery, L et al

in Journal of Clinical Virology (2011), 52(3), 181-6

BACKGROUND: HIV-1 viral load assays are critical tools to monitor antiretroviral therapy efficacy in HIV-infected patients. Two assays based on real-time PCR are available, the Abbott Real-Time HIV-1 ... [more ▼]

BACKGROUND: HIV-1 viral load assays are critical tools to monitor antiretroviral therapy efficacy in HIV-infected patients. Two assays based on real-time PCR are available, the Abbott Real-Time HIV-1 assay (Abbott assay) and the new Roche COBAS((R)) AmpliPrep/COBAS((R)) TaqMan((R)) HIV-1 test, v. 2.0 (TaqMan((R)) test v2.0). OBJECTIVES: We have compared the performance of the two assays in 546 clinical plasma specimens of group M strains from Luxembourg and Rwanda. STUDY DESIGN: Our analyses focused on subtype inclusivity and platforms accuracy for 328 low level viremia samples. RESULTS: Strong agreement and linear correlation were observed between the two assays (R(2) = 0.95) over a wide dynamic range. Bland-Altman analysis showed a mean difference of 0.04 log 10 indicating minimal overall viral load quantification differences between both platforms. One subtype C was severely underquantified by TaqMan((R)) test v2.0 for which sequence analysis revealed multiple mismatches between the viral sequence and the primer/probe regions. A non significant lower quantification of the Abbott assay was shown for subtype A1 with a mean log 10 difference of 0.24. For specimens under 200 cp/mL, the overall agreement was 90% at the cut-off of 50 cp/mL and 67% at assay's lower limit of detection of 20 and 40 cp/mL. 309 samples were retested by the COBAS((R)) AMPLICOR((R)) HIV-1 MONITOR Test, v. 1.5 and a lack of agreement between the three assays around their lower limit of quantification was revealed. CONCLUSIONS: Both real-time tests were closely comparable in the quantification of viral load specimens of ten HIV-1 subtypes and recombinant forms. [less ▲]

Detailed reference viewed: 16 (0 ULg)
Full Text
Peer Reviewed
See detailHigh density resolution synchrotron radiation based X-ray microtomography (SR mu CT) for quantitative 3D-morphometrics in zoological sciences
Nickel, Michael; Hammel, Jörg U; Herzen, Julia et al

in Proceedings of SPIE (2008), 7078

Zoological sciences widely rely on morphological data to reconstruct and understand body structures of animals. The best suitable methods like tomography allow for a direct representation of 3D-structures ... [more ▼]

Zoological sciences widely rely on morphological data to reconstruct and understand body structures of animals. The best suitable methods like tomography allow for a direct representation of 3D-structures. In recent years, synchrotron radiation based X-ray microtomography (SR mu CT) placed high resolutions to the disposal of morphologists. With the development of highly brilliant and collimated third generation synchrotron sources, phase contrast SR mu CT became widely available. A number of scientific contributions stressed the superiority of phase contrast over absorption contrast. However, here we demonstrate the power of high density resolution methods based on absorption-contrast SR mu CT for quantitative 3D-measurements of tissues and other delicate bio-structures in zoological sciences. We used beamline BW2 at DORIS III (DESY, Hamburg, Germany) to perform microtomography on tissue and mineral skeletons of marine sponges (Porifera) which were shock frozen and/or fixed in a glutamate osmium tetroxide solution, followed by critical point drying. High density resolution tomographic reconstructions allowed running quantitative 3D-image analyses in Matlab and ImageJ. By applying contrast and shape rule based algorithms we semi-automatically extracted and measured sponge body structures like mineral spicules, elements of the canal system or tissue structures. This lead to a better understanding of sponge biology: from skeleton functional morphology and internal water flow regimes to body contractility. Our high density resolution based quantitative approach can be applied to a wide variety of biological structures. However, two prerequisites apply: (1) maximum density resolution is necessary; (2) edge effects as seen for example in phase outline contrast SR mu CT must not be present. As a consequence, to allow biological sciences to fully exploit the power of SR mu CT further increase of density resolution in absorption contrast methods is desirable. [less ▲]

Detailed reference viewed: 46 (0 ULg)
Full Text
Peer Reviewed
See detailHigh Diversity in Cretaceous Ichthyosaurs from Europe Prior to Their Extinction
Fischer, Valentin ULg; Bardet, Nathalie; Guiomar, Myette et al

in PLoS ONE (2014), 9(1), 84709

Background: Ichthyosaurs are reptiles that inhabited the marine realm during most of the Mesozoic. Their Cretaceous representatives have traditionally been considered as the last survivors of a group ... [more ▼]

Background: Ichthyosaurs are reptiles that inhabited the marine realm during most of the Mesozoic. Their Cretaceous representatives have traditionally been considered as the last survivors of a group declining since the Jurassic. Recently, however, an unexpected diversity has been described in Upper Jurassic–Lower Cretaceous deposits, but is widely spread across time and space, giving small clues on the adaptive potential and ecosystem control of the last ichthyosaurs. The famous but little studied English Gault Formation and ‘greensands’ deposits (the Upper Greensand Formation and the Cambridge Greensand Member of the Lower Chalk Formation) offer an unprecedented opportunity to investigate this topic, containing thousands of ichthyosaur remains spanning the Early–Late Cretaceous boundary. Methodology/Principal findings: To assess the diversity of the ichthyosaur assemblage from these sedimentary bodies, we recognized morphotypes within each type of bones. We grouped these morphotypes together, when possible, by using articulated specimens from the same formations and from new localities in the Vocontian Basin (France); a revised taxonomic scheme is proposed. We recognize the following taxa in the ‘greensands’: the platypterygiines ‘Platypterygius’ sp. and Sisteronia seeleyi gen. et sp. nov., indeterminate ophthalmosaurines and the rare incertae sedis Cetarthrosaurus walkeri. The taxonomic diversity of late Albian ichthyosaurs now matches that of older, well-known intervals such as the Toarcian or the Tithonian. Contrasting tooth shapes and wear patterns suggest that these ichthyosaurs colonized three distinct feeding guilds, despite the presence of numerous plesiosaur taxa. Conclusion/Significance: Western Europe was a diversity hot-spot for ichthyosaurs a few million years prior to their final extinction. By contrast, the low diversity in Australia and U.S.A. suggests strong geographical disparities in the diversity pattern of Albian–early Cenomanian ichthyosaurs. This provides a whole new context to investigate the extinction of these successful marine reptiles, at the end of the Cenomanian. [less ▲]

Detailed reference viewed: 26 (2 ULg)
Peer Reviewed
See detailHigh diversity in late Early Cretaceous ichthyosaurs
Fischer, Valentin ULg; Guiomar, Myette; Godefroit, Pascal

Poster (2009, October)

Considered as the last survivors of a dying group, all Cretaceous ichthyosaurs have traditionally been incorporated within a single genus, Platypterygius. This waste-basket genus includes large ... [more ▼]

Considered as the last survivors of a dying group, all Cretaceous ichthyosaurs have traditionally been incorporated within a single genus, Platypterygius. This waste-basket genus includes large ichthyosaurs with numerous, large and conical tooth crowns and bulbous polygonal root well anchored in dental grooves. With such a dentition, Platypterygius can be included within the “Smash guild”. However, the study of new specimens from the Aptian-Albian marls of the Vocontian basin (SE France) reveals an unexpected diversity of late Early Cretaceous ichthyosaurs. Beside “classical” Platypterygius specimens, another type of ichthyosaur with very tiny and pointed teeth has been found in the mid-Albian marls of Sisteron, in High-Provence Alps. This new taxon is based on a partial crushed skull, two basioccipitals, 8 teeth, and 15 centra. The teeth range from 20mm to 2cm and are highly compressed labio-lingualy, with a thickness/wideness ratio of the root sometimes as low as 1/4. Crowns are slightly curved and sharply pointed, indicating a diet of small and soft preys. Interestingly, although the rostral bones are slender and delicate – thus radically different from conventional Late Early Cretaceous ichthyosaurs – the basioccipital of this taxon shares many characters with Platypterygius and is of the same overall size. Together with the recently named genus Maiaspondylus from the Albian of western Canada, these specimens suggest a higher diversity of late Early Cretaceous ichthyosaurs, in contradiction with the current view of ichthyosaur extinction, said to be gradually decreasing in diversity since the Middle Jurassic. In fact, the number of ecological niches occupied by ichthyosaurs apparently even increased from the Late Jurassic until the late Early Cretaceous. Therefore, the ecological impact of the Cenomanian-Turonian boundary on marine reptile faunas was probably more severe than previously thought. [less ▲]

Detailed reference viewed: 252 (5 ULg)
Peer Reviewed
See detailHigh diversity in late Early Cretaceous ichthyosaurs part II: The Cambridge Greensand material
Fischer, Valentin ULg

Conference (2011, September)

Recent and on-going work on Canadian and French Cretaceous ichthyosaurs has unveiled a high diversity of Albian ophthalmosaurids, suggesting the extinction of ichthyosaurs which occurs during the ... [more ▼]

Recent and on-going work on Canadian and French Cretaceous ichthyosaurs has unveiled a high diversity of Albian ophthalmosaurids, suggesting the extinction of ichthyosaurs which occurs during the Cenomanian was a much more severe event than previously supposed. Yet the ichthyosaur assemblages from other areas such as the USA and Australia are monospecific, suggesting that the diversity of ichthyosaurs was not universally high. The Cambridge Greensand ichthyosaur material, which has not been the subject of any thorough study since 1869, consists of about 900 specimens, the vast majority of which are isolated bones. Nevertheless, this abundant material offers a good opportunity to assess the diversity of the ichthyosaurs that roamed the western England Sea during the late Albian–Early Cenomanian interval. In order to assess this diversity, diagnostic bones such as basioccipitals, stapes, humeri and femora were compared to that of other ophthalmosaurids. Several morphotypes, some represented by 10+ specimens are recognized. Articulated specimens were used to unite cranial and appendicular bone morphotypes to a taxon. An extremely diverse assemblage of at least 5 distinct taxa is recognized in the Cambridge Greensand Formation: Platypterygius sp., two new genera that have representatives in southeastern France and Germany, a Brachypterygius/Aegirosaurus morphotype, and the long-forgotten but diagnostic Cetarthrosaurus walkeri, for which we found a second and better preserved specimen. The diversity of the ‘mid’ Cretaceous ichthyosaurs from Europe now matches that of the Early Jurassic, a period sometimes seen as the ‘Golden Age’ of post-Triassic ichthyosaurs. [less ▲]

Detailed reference viewed: 77 (3 ULg)
Full Text
Peer Reviewed
See detailHigh doses of transplanted CD34(+) cells are associated with rapid T-cell engraftment and lessened risk of graft rejection, but not more graft-versus-host disease after nonmyeloablative conditioning and unrelated hematopoietic cell transplantation
Baron, Frédéric ULg; Maris, M. B.; Storer, B. E. et al

in Leukemia (2005), 19(5), 822-828

This report examines the impact of graft composition on outcomes in 130 patients with hematological malignancies given unrelated donor granulocyte-colony-stimulating-factor-mobilized peripheral blood ... [more ▼]

This report examines the impact of graft composition on outcomes in 130 patients with hematological malignancies given unrelated donor granulocyte-colony-stimulating-factor-mobilized peripheral blood mononuclear cells (G-PBMC) ( n = 116) or marrow ( n = 14) transplantation after nonmyeloablative conditioning with 90 mg/m(2) fludarabine and 2Gy TBI. The median number of CD34(+) cells transplanted was 6.5 x 10(6)/ kg. Higher numbers of grafted CD14(+) ( P = 0.0008), CD3(+) ( P = 0.0007), CD4(+) ( P = 0.001), CD8(+) ( P = 0.004), CD3 - CD56(+) ( P = 0.003), and CD34(+) ( P = 0.0001) cells were associated with higher levels of day 28 donor T-cell chimerism. Higher numbers of CD14(+) ( P = 0.01) and CD34(+) ( P = 0.0003) cells were associated with rapid achievement of complete donor T-cell chimerism, while high numbers of CD8(+) ( P = 0.005) and CD34(+) ( P = 0.01) cells were associated with low probabilities of graft rejection. When analyses were restricted to G-PBMC recipients, higher numbers of grafted CD34(+) cells were associated with higher levels of day 28 donor T-cell chimerism ( P = 0.01), rapid achievement of complete donor T-cell chimerism ( P = 0.02), and a trend for lower risk for graft rejection ( P = 0.14). There were no associations between any cell subsets and acute or chronic GVHD nor relapse/progression. These data suggest more rapid engraftment of donor T cells and reduced rejection rates could be achieved by increasing the doses of CD34(+) cells in unrelated grafts administered after nonmyeloablative conditioning. [less ▲]

Detailed reference viewed: 27 (0 ULg)
Full Text
See detailHigh dynamic range interferometric observations of exozodiacal discs: performance comparison between ground, space, and Antarctica
Absil, Olivier ULg; Defrere, Denis; Coudé du Foresto, Vincent et al

in Schöller, Markus; Danchi, William; Delplancke, Françoise (Eds.) Optical and Infrared Interferometry (2008, July 01)

The possible presence of large amounts of exozodiacal dust around nearby main sequence stars represents a threat to the detection and characterisation of Earth-like extrasolar planets with future infrared ... [more ▼]

The possible presence of large amounts of exozodiacal dust around nearby main sequence stars represents a threat to the detection and characterisation of Earth-like extrasolar planets with future infrared space interferometers such as DARWIN or TPF. In this paper, we first review the current detection capabilities of ground-based infrared interferometers such as CHARA/FLUOR and the detections of hot dust that have been obtained so far around a few main sequence stars. With the help of realistic instrumental simulations, we then discuss the relative merits of various ground-based sites (temperate and Antarctic) versus space-based observatories for the detection of exozodiacal discs down to a few zodi by interferometric nulling as a preparation to future life-finding missions. In particular, we discuss the performance of four proposed nulling interferometers: GENIE, ALADDIN, PEGASE and FKSI. An optimised strategy for the characterisation of candidate DARWIN/TPF targets is finally proposed. [less ▲]

Detailed reference viewed: 10 (0 ULg)
Full Text
Peer Reviewed
See detailHigh energy and short pulses generation by Nd:yttrium aluminum garnet laser mode-locked using frequency-doubling nonlinear mirror
Mani, A. A.; Lis, D.; Grawet, L. et al

in Optics Communications (2007), 276

The generation of laser pulses with energies of >40 mJ at 25 Hz and durations variable from 15 ps to 45 ps using an Nd:yttrium aluminum garnet laser mode-locked with a Stankov nonlinear mirror is ... [more ▼]

The generation of laser pulses with energies of >40 mJ at 25 Hz and durations variable from 15 ps to 45 ps using an Nd:yttrium aluminum garnet laser mode-locked with a Stankov nonlinear mirror is demonstrated. This laser is used to pump an optical parametric generator-amplifier, which is tunable in the visible spectral range. [less ▲]

Detailed reference viewed: 14 (1 ULg)
See detailHigh energy environment offshore deposits in the western Gulf of Corinth, Greece
Beckers, Arnaud ULg; Mortier, Clément; Beck, Christian et al

Conference (2013, April)

Detailed reference viewed: 46 (13 ULg)
Full Text
Peer Reviewed
See detailHigh energy, high resolution x-ray tomography applied to catalytic distillation packings
Toye, Dominique ULg; Le Trong, Emmanuel; Marchot, Pierre ULg et al

Conference (2005)

Detailed reference viewed: 10 (2 ULg)
Full Text
Peer Reviewed
See detailHigh field behavior of artificially engineered boundaries in melt-processed YBa2Cu3O7-delta
Doyle, R. A.; Bradley, A. D.; Lo, W. et al

in Applied Physics Letters (1998), 73(1), 117-119

Artificial bulk "zero-angle" boundaries parallel to the c axis have been engineered between large melt-processed YBa2CU3O7-delta (YBCO) grains and observed to carry a transport supercurrent at fields up ... [more ▼]

Artificial bulk "zero-angle" boundaries parallel to the c axis have been engineered between large melt-processed YBa2CU3O7-delta (YBCO) grains and observed to carry a transport supercurrent at fields up to at least 5 T at 77 K. The temperature and angular dependencies of the boundary resistance have exactly the same form as those of the grains, which is evidence that the grains are intimately coupled. The limiting mechanism for current transfer across these boundaries is, therefore, not a simple weak link or Josephson effect. This joining technique is extremely promising for production of macroscopic engineering artifacts. (C) 1998 American Institute of Physics. [less ▲]

Detailed reference viewed: 80 (1 ULg)