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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 ULiege; 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 ▲]

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See detailHigh dendritic expression of Ih in the proximity of the axon origin controls the integrative properties of nigral dopamine neurons.
Engel, Dominique ULiege; Seutin, Vincent ULiege

in Journal of Physiology (2015), 593(22), 4905-4922

Dendrites of most neurons express voltage-gated ion channels in their membrane. In combination with passive properties, active currents confer to dendrites a high computational potential. The ... [more ▼]

Dendrites of most neurons express voltage-gated ion channels in their membrane. In combination with passive properties, active currents confer to dendrites a high computational potential. The hyperpolarization-activated cation current Ih present in the dendrites of some pyramidal neurons affects their membrane and integration properties, synaptic plasticity and higher functions such as memory. A gradient of increasing h-channel density towards distal dendrites has been found to be responsible for the location independence of excitatory postsynaptic potential (EPSP) waveform and temporal summation in cortical and hippocampal pyramidal cells. However, reports on other cell types revealed that smoother gradients or even linear distributions of Ih can achieve homogeneous temporal summation. Although the existence of a robust, slowly activating Ih current has been repeatedly demonstrated in nigral dopamine neurons, its subcellular distribution and precise role in synaptic integration are unknown. Using cell-attached patch-clamp recordings, we find a higher Ih current density in the axon-bearing dendrite than in the soma or in dendrites without axon in nigral dopamine neurons. Ih is mainly concentrated in the dendritic membrane area surrounding the axon origin and decreases with increasing distances from this site. Single EPSPs and temporal summation are similarly affected by blockade of Ih in axon- and non-axon-bearing dendrites. The presence of Ih close to the axon is pivotal to control the integrative functions and the output signal of dopamine neurons and may consequently influence the downstream coding of movement. [less ▲]

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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 ▲]

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See detailHigh dimensional endophenotype ranking in the search for major depression risk genes.
Glahn, David C.; Curran, Joanne E.; Winkler, Anderson ULiege et al

in Biological Psychiatry (2012), 71(1), 6-14

BACKGROUND: Despite overwhelming evidence that major depression is highly heritable, recent studies have localized only a single depression-related locus reaching genome-wide significance and have yet to ... [more ▼]

BACKGROUND: Despite overwhelming evidence that major depression is highly heritable, recent studies have localized only a single depression-related locus reaching genome-wide significance and have yet to identify a causal gene. Focusing on family-based studies of quantitative intermediate phenotypes or endophenotypes, in tandem with studies of unrelated individuals using categorical diagnoses, should improve the likelihood of identifying major depression genes. However, there is currently no empirically derived statistically rigorous method for selecting optimal endophentypes for mental illnesses. Here, we describe the endophenotype ranking value, a new objective index of the genetic utility of endophenotypes for any heritable illness. METHODS: Applying endophenotype ranking value analysis to a high-dimensional set of over 11,000 traits drawn from behavioral/neurocognitive, neuroanatomic, and transcriptomic phenotypic domains, we identified a set of objective endophenotypes for recurrent major depression in a sample of Mexican American individuals (n = 1122) from large randomly selected extended pedigrees. RESULTS: Top-ranked endophenotypes included the Beck Depression Inventory, bilateral ventral diencephalon volume, and expression levels of the RNF123 transcript. To illustrate the utility of endophentypes in this context, each of these traits were utlized along with disease status in bivariate linkage analysis. A genome-wide significant quantitative trait locus was localized on chromsome 4p15 (logarithm of odds = 3.5) exhibiting pleiotropic effects on both the endophenotype (lymphocyte-derived expression levels of the RNF123 gene) and disease risk. CONCLUSIONS: The wider use of quantitative endophenotypes, combined with unbiased methods for selecting among these measures, should spur new insights into the biological mechanisms that influence mental illnesses like major depression. [less ▲]

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See detailHigh Diversity in Cretaceous Ichthyosaurs from Europe Prior to Their Extinction
Fischer, Valentin ULiege; 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 ▲]

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See detailHigh diversity in late Early Cretaceous ichthyosaurs
Fischer, Valentin ULiege; 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 ▲]

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See detailHigh diversity in late Early Cretaceous ichthyosaurs part II: The Cambridge Greensand material
Fischer, Valentin ULiege

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 ▲]

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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 ULiege; 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 ▲]

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See detailHigh Dynamic Range Imaging with the FIRST instrument
Perrin, G.; Lacour, S.; Huby, Elsa ULiege et al

Conference (2010, October 01)

A concept to achieve high dynamic range images from the ground is presented. The main idea is to calibrate turbulent fluctuations of wavefronts in a telescope pupil with a fibered fully redundant aperture ... [more ▼]

A concept to achieve high dynamic range images from the ground is presented. The main idea is to calibrate turbulent fluctuations of wavefronts in a telescope pupil with a fibered fully redundant aperture mask. This is the principle of the FIRST instrument whose first prototype version is to see stellar photons in July 2010 at Lick Observatory. Lab results and hopefully first sky results will be presented. [less ▲]

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See detailHigh dynamic range interferometric observations of exozodiacal discs: performance comparison between ground, space, and Antarctica
Absil, Olivier ULiege; Defrere, Denis ULiege; 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 ▲]

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See detailHigh dynamic range thermal infrared imager for the VLTI
Defrere, Denis ULiege; Absil, Olivier ULiege; Ertel, Steve et al

in Pott, Jörg-Uwe; Surdej, Jean (Eds.) Future of otpical-infrared interferometry in Europe (2017)

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See detailHigh Efficiency Volume Bragg Gratings for Spectrometry and space applications: Space qualification report
Loicq, Jerôme ULiege; Georges, Marc ULiege

Report (2012)

This document presents the results of the assembly, integration and validation of the VBG test benches

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See detailHigh Efficiency Volume Bragg Gratings for Spectrometry and space applications: Technology survey & Trade-off analysis
Loicq, Jerôme ULiege; Barbier, Christian ULiege; Georges, Marc ULiege

Report (2012)

This document presents the results of the technology trade-off on gratings technologies. The first part of this document presents a technology survey which describes following technologies: - Surface ... [more ▼]

This document presents the results of the technology trade-off on gratings technologies. The first part of this document presents a technology survey which describes following technologies: - Surface relief grating - Volume Bragg grating - Grisms or immersed grating In the case of VBG’s two specific material are considered: - Dichromated gelatine (DCG) - Photothermal refractive grating (PTR). These cases are considered in two configurations transmission and reflection mode. The second part of the document presents the results of trade-off analysis focused on VBG’s technologies. A whole set of parameters about PTR and DCG are presented. These parameters were obtained by Kogelnik theory and RCW analysis. Manufacturing and physical parameters have been chosen to be compliant with ESA specifications. Results of this analysis will drive the choices of adequate spectral bands and related VBG technologies to test in the next steps of the project. [less ▲]

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See detailHigh Efficiency Volume Bragg Gratings for Spectrometry and space applications:VBG experimental characterization program
Loicq, Jerôme ULiege; Georges, Marc ULiege

Report (2012)

This document presents a validation program plan on Volume Bragg grating. The objectives are to define and describe the test to be performed on VBG’s for space component. qualification.

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