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See detailThe limnology and biology of the Dufek Massif, Transantarctic Mountains 82° South
Hodgson, Dominic A; Convey, Pete; Verleyen, Elie et al

in Polar Science (2010), 4

Very little is known about the higher latitude inland biology of continental Antarctica. In this paper we describe the limnology and biology of the Dufek Massif, using a range of observational ... [more ▼]

Very little is known about the higher latitude inland biology of continental Antarctica. In this paper we describe the limnology and biology of the Dufek Massif, using a range of observational, microscopic and molecular methods. Here two dry valleys are home to some of the southernmost biota on Earth. Cyanobacteria were the dominant life forms, being found in lakes and ponds, in hypersaline brines, summer melt water, relict pond beds and in exposed terrestrial habitats. Their species diversity was the lowest yet observed in Antarctic lakes. Green algae, cercozoa and bacteria were present, but diatoms were absent except for a single valve; likely windblown. Mosses were absent and only one lichen specimen was found. The Metazoa included three microbivorous tardigrades (Acutuncus antarcticus, Diphascon sanae and Echiniscus (cf) pseudowendti) and bdelloid rotifer species, but no arthropods or nematodes. These simple faunal and floral communities are missing most of the elements normally present at lower latitudes in the Antarctic which is probably a result of the very harsh environmental conditions in the area. [less ▲]

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See detailLiMSO(4)F (M = Fe, Co and Ni): promising new positive electrode materials through the DFT microscope
Frayret, Christine; Villesuzanne, Antoine; Spaldin, Nicola et al

in Physical Chemistry Chemical Physics [=PCCP] (2010), 12(47), 15512-15522

A theoretical study of the lithium intercalated LiMSO(4)F and deintercalated MSO(4)F systems, where M = Fe, Co and Ni has been performed within the framework of density functional theory. Beyond ... [more ▼]

A theoretical study of the lithium intercalated LiMSO(4)F and deintercalated MSO(4)F systems, where M = Fe, Co and Ni has been performed within the framework of density functional theory. Beyond predictions of structural evolution and average voltages versus a lithium electrode, we have applied partial density of states and Bader's topological analysis of the electron density to the study of lithium deintercalation. Upon lithium extraction, charge rearrangement occurs for nickel between different d-orbitals, but with little net positive charge gain, while cobalt and iron atoms end up with a clear oxidized state. The participation of oxygen ions in accepting the electron of the lithium is thus enhanced for LiNiSO(4)F. However, this effect does not affect the long-range electrostatic interactions a lot in the lithiated phase, since the valence of all transition metals is very close due to initial lower oxidized state for the Ni atom in the host. It is found that this is not essentially a long-range electrostatic interaction within the lithiated phase but within the host which explains, at least partly, the increase in voltage by passing from Fe to Ni. Our results also shed light upon the possibility of getting an approximate evaluation of the local strain associated with delithiation from the atomic volume evolutions, which are also likely to affect the electrochemical potential. [less ▲]

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See detailLinagliptin for the treatment of type 2 diabetes (pharmacokinetic evaluation).
SCHEEN, André ULg

in Expert Opinion on Drug Metabolism & Toxicology (2011), 7(12), 1561-76

Introduction: Dipeptidyl peptidase-4 (DPP-4) inhibitors offer new options for the management of type 2 diabetes (T2DM). The novel compound linagliptin has important different pharmacokinetic (PK ... [more ▼]

Introduction: Dipeptidyl peptidase-4 (DPP-4) inhibitors offer new options for the management of type 2 diabetes (T2DM). The novel compound linagliptin has important different pharmacokinetic (PK) properties, when compared with previously commercialized DPP-4 inhibitors, which may offer some advantages in clinical practice. Linagliptin has a unique PK/pharmacodynamic (PD) profile and is the first DPP-4 inhibitor with a nonrenal elimination route. Therefore, it can be administered in patients with renal impairment without dose adjustment or monitoring of renal function. The drug has a low potential for drug-drug interactions (DDIs) and no clinically relevant ones were reported so far. Areas covered: An extensive literature search was performed to analyse primarily PK and secondarily PD characteristics of linagliptin in both healthy volunteers and patients with T2DM (treated with linagliptin as monotherapy or combined therapy). Updated information about linagliptin PK either after single administration (large dose range) or after chronic administration (steady state) were also included. A special focus has been put on DDIs and on PK/PD of linagliptin in patients with renal impairment. Expert opinion: Head-to-head comparative studies and/or increased clinical experience with DPP-4 inhibitors will determine the clinical advantage, if any, of one agent over another. [less ▲]

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See detailLinagliptin plus metformin: a pharmacokinetic and pharmacodynamic evaluation.
SCHEEN, André ULg

in Expert Opinion on Drug Metabolism & Toxicology (2013), 9(3), 363-77

INTRODUCTION: The first-choice drug therapy in the management of type 2 diabetes is metformin . However, most patients require a combined therapy to reach and/or maintain targets of glucose control ... [more ▼]

INTRODUCTION: The first-choice drug therapy in the management of type 2 diabetes is metformin . However, most patients require a combined therapy to reach and/or maintain targets of glucose control. Dipeptidyl peptidase-4 (DPP-4) inhibitors, commonly referred to as gliptins, offer new options for combined therapy with metformin. Linagliptin is the most recently launched gliptin, with a unique pharmacokinetic (PK) profile characterized by negligible renal excretion and is now also available as a fixed-dose combination (FDC) with metformin. AREAS COVERED: An extensive literature search was performed to analyze the potential PK and pharmacodynamic interactions between linagliptin and metformin. Linagliptin and metformin may be administered together, either separately or as FDC supported by bioequivalence studies. Linagliptin and metformin are not prone to PK drug-drug interactions. Their coadministration improves blood glucose control more potently than either compound separately, without hypoglycemia and without increasing metformin-related gastrointestinal side effects. EXPERT OPINION: The combination linaglitpin plus metformin, if not contraindicated (renal failure), may be used as first-line or second-line therapy in the management of type 2 diabetes. That being said, the durability of the glucose-lowering effect of this combination needs to be further explored in long-term controlled trials. [less ▲]

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See detailThe Lincombian-Ranisian-Jermanowician and the limit of the Aurignacian spreading on the northern European plain
Flas, Damien ULg

in Djindjian, François; Kozlowski, Janusz; Bicho, Nuno (Eds.) Le concept de territoires dans le Paléolithique supérieur européen (2009)

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See detailLindane et goudron dans les shampoings: quelle toxicité ?
Theunis, Laetitia ULg

Conference (2008, December)

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See detailLine Cluster Detection Using A Variant Of The Hough Transform For Culture Row Localisation
Leemans, Vincent ULg; Destain, Marie-France ULg

in Image and Vision Computing (2006), 24(5),

An adaptation of the Hough transform was proposed for the detection of line clusters of known geometry. This method was applied in agriculture for the detection of sowing furrows created by a driller and ... [more ▼]

An adaptation of the Hough transform was proposed for the detection of line clusters of known geometry. This method was applied in agriculture for the detection of sowing furrows created by a driller and of chicory plant rows during harvesting process. The sowing rows were revealed by a background correction, the background being obtained thanks to a median rank filter. The method was found efficient in eliminating the shadows. For the crop rows, a neural network was used to localise the plants. While the petiole and the leaves were easily separated from the soil, the chicory root and the soil having about the same colour and the lighting condition varying widely, it was more difficult to obtain a good contrast between those parts, which leaves place for some improvements. The adapted Hough transform consisted in computing one transform for each line in the cluster with, for reference, the position and direction of the theoretical position of the row. The different transforms were then added. It was found effective for both the sowing rows and the chicory rows. Results remained good even in very noisy conditions, when the rows were incomplete or when artefacts would lead its classical counter part to show several alignments other than the expected ones. The culture rows were localised with a precision of a few centimetres which was compatible with the proposed applications. [less ▲]

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See detailLine narrowing effect on the retrieval of HF and HCl vertical profiles from ground-based FTIR measurements
Barret, Brice; Hurtmans, Daniel; Carleer, Michel R. et al

in Journal of Quantitative Spectroscopy & Radiative Transfer (2005), 95(4), 499-519

Collision-induced line narrowing, which has been discovered in the 1950s and investigated thoroughly in the laboratory since then, has yet never been taken into account in the spectroscopic remote sensing ... [more ▼]

Collision-induced line narrowing, which has been discovered in the 1950s and investigated thoroughly in the laboratory since then, has yet never been taken into account in the spectroscopic remote sensing of the atmosphere. This work investigates the effect of collision-induced line narrowing onto the retrieval of HCl and HF vertical profiles from ground-based solar absorption FTIR measurements made at the NDSC station of the Jungfraujoch (46.5 degrees N, 8 degrees E and 3580 m above see level). The retrievals are performed with the Atmosphit software, recently developed at the Universite Libre de Bruxelles. It is presented in this paper for the first time and is validated against the widely used SFIT2 software. The impact of the line narrowing onto the retrieval of HCl and HF vertical profiles is examined relying on careful information content and error budget analyses. We report that the effect is relatively weak for HCl but significant for HF. Confirmation of the need to take the line narrowing into account for the retrieval of vertical profiles from ground-based FTIR spectra is given by comparison with data from the HALOE space borne instrument, rather insensitive to this spectroscopic effect. (c) 2005 Elsevier Ltd. All rights reserved. [less ▲]

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See detailLine profile variability in the massive binary HD 152219
Sana, H.; Gosset, Eric ULg

in Communication in Asteroseismology (2009, July 01), 158

HD 152219 is a massive binary system with O9.5 III and B1-2 III/V components and a short orbital period of 4.2 d. In a previous work, we showed that the primary star (M_{prim}˜21 M_&sun;) was presenting ... [more ▼]

HD 152219 is a massive binary system with O9.5 III and B1-2 III/V components and a short orbital period of 4.2 d. In a previous work, we showed that the primary star (M_{prim}˜21 M_&sun;) was presenting clear line profile variabilities (LPVs) that might be caused by nonradial pulsations (NRPs). In the present work, we report on an intensive spectroscopic monitoring, that aimed at unveiling the nature of the detected LPVs. Based on this new data set, we discard the NRPs and point out the Rossiter-McLaughlin effect as % being the cause of the observed LPVs. The upper limit derived on the amplitude of undetected NRPs, if any, is set at a couple of part per thousands of the continuum level. [less ▲]

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See detailLine profile variability in the spectra of Oef stars - II. HD192281, HD14442 and HD14434
De Becker, Michaël ULg; Rauw, Grégor ULg

in Astronomy and Astrophysics (2004), 427(3), 995-1008

We present the very first analysis of the spectroscopic variability of the three rapidly rotating Oef stars HD 192281 (O5(ef)), HD14442 (O5.5ef) and HD 14434 (O6.5( ef)). Radial velocities of the He II ... [more ▼]

We present the very first analysis of the spectroscopic variability of the three rapidly rotating Oef stars HD 192281 (O5(ef)), HD14442 (O5.5ef) and HD 14434 (O6.5( ef)). Radial velocities of the He II lambda 4541 line reveal no evidence of binarity on time scales of a few days, or from one year to the next, for any of the targets. The He II lambda 4686 double-peaked emission and, to some extent, the H absorption line display significant profile variability in the spectra of all three stars. Data gathered during different observing runs spread over six years reveal a rather stable time scale for HD 192281 and HD14442, whereas the variability pattern changes significantly from one year to the other. The case of HD 14434 is less clear as no obvious time scale emerges from our analysis. In a tentative way to interpret this variability, stellar rotation remains a possible clock for HD 192281 and HD14442. However, currently available models addressing stellar rotation fail to explain some crucial aspects of the observed variability behaviour, which appear to be even more complex in the case of HD 14434. [less ▲]

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See detailLine profile variability in the spectra of Oef stars. I. BD + 60deg 2522
Rauw, Grégor ULg; De Becker, Michaël ULg; Vreux, Jean-Marie ULg

in Astronomy and Astrophysics (2003), 399

We report the analysis of a long term observing campaign designed to monitor the spectroscopic variability of the Oef star BD +60deg 2522. We find that the double-peaked He {II} lambda 4686 emission line ... [more ▼]

We report the analysis of a long term observing campaign designed to monitor the spectroscopic variability of the Oef star BD +60deg 2522. We find that the double-peaked He {II} lambda 4686 emission line undergoes strong profile variability on time scales of 2-3 day. However, the time scale as well as the pattern of these variations turn out to be epoch dependent and the phenomenon is thus most likely not ruled by a single stable clock. On the other hand, the absorption lines in the spectrum of BD +60deg 2522 display line profile variability on time scales of a few hours that might be related to non-radial pulsations. We tentatively propose that the beating of several non-radial pulsation modes triggers transient large-scale density perturbations in a confined stellar wind that produce the 2-3 day time scale variability. [less ▲]

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See detailLine profile variability in the spectrum of the O(f) supergiant HD 192639
Rauw, Grégor ULg; Vreux, Jean-Marie ULg

in Astronomy and Astrophysics (1998), 335

We report the results of a medium-resolution spectroscopic investigation of the O(f) supergiant HD 192639. Particular attention is paid to the He {ii}\ lambda 4686 line. This line displays strong profile ... [more ▼]

We report the results of a medium-resolution spectroscopic investigation of the O(f) supergiant HD 192639. Particular attention is paid to the He {ii}\ lambda 4686 line. This line displays strong profile variability on time scales of a few days, changing from a P-Cygni profile with a double-peaked emission component to a pure blue-shifted emission line. It appears that the variability of most of the absorption lines present in our spectra is correlated to the deformation of the He {ii}\ lambda 4686 line and arises probably from a large scale structure in the low-velocity part of the stellar wind rather than from a photospheric phenomenon. We find that the time scale of the variability could be consistent with the estimated rotational period of HD 192639. Based on observations collected at the Observatoire de Haute Provence, France. [less ▲]

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See detailLine profiles in expanding envelopes
Surdej, Jean ULg

in Astronomy and Astrophysics (1979), 73

An attempt is made to show how the physical and geometrical parameters prevailing in an expanding stellar envelope can be inferred from an analysis of one or more observed line profiles. Attention is ... [more ▼]

An attempt is made to show how the physical and geometrical parameters prevailing in an expanding stellar envelope can be inferred from an analysis of one or more observed line profiles. Attention is given to the Sobolev approximation, line formation in outwardly accelerating envelopes, effects of a stellar core, and radiative transfer in outwardly decelerating envelopes. General equations are derived for both types of envelope, and some typical solutions are presented. Application of the method to P Cygni lines is discussed. [less ▲]

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See detailThe line spectrum of the solar Corona
Swings, Polydore ULg

in Publications of the Astronomical Society of the Pacific [=PASP] (1945), 57

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See detailLine-by-line calculations of thermal infrared radiation representative for global condition: CFC-12 as an example
Myhre, Gunnar; Stordal, Frode; Gausemel, Ingvil et al

in Journal of Quantitative Spectroscopy & Radiative Transfer (2006), 97(3), 317-331

We estimate a current direct radiative forcing due to CFC-12 of 0.18 Wm(-2), which is likely to be the peak radiative forcing for CFC-12. Global measurements of CFC-12 show at present an almost negligible ... [more ▼]

We estimate a current direct radiative forcing due to CFC-12 of 0.18 Wm(-2), which is likely to be the peak radiative forcing for CFC-12. Global measurements of CFC-12 show at present an almost negligible trend for CFC-12 and measurement in an industrialized region show evidence that the peak concentration is reached. It is expected that concentration of CFC-12 in industrialized regions begins to decline 1-3 years before the global concentration. Our radiative forcing calculations are based on a line-by-line model appropriate for simulation of global mean radiative forcing, including clouds and stratospheric temperature adjustment. The radiative forcing of 0.33 Wm(-2)/ppbv is close to earlier published results for this compound. New spectroscopic measurements for CFC-12 are performed and compared to previously published results. (C) 2005 Elsevier Ltd. All rights reserved. [less ▲]

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See detailA line-profile analysis of the large-amplitude beta Cephei star xi1 Canis Majoris
Saesen, S.; Briquet, Maryline ULg; Aerts, C.

in Communications in Asteroseismology (2006), 147

We present a detailed line-profile study of the beta Cephei star xi1 Canis Majoris, for which we have assembled numerous high-resolution spectra over a period of 4.5 years. It is the first time that the ... [more ▼]

We present a detailed line-profile study of the beta Cephei star xi1 Canis Majoris, for which we have assembled numerous high-resolution spectra over a period of 4.5 years. It is the first time that the line-profile variations of this star have been analysed. We focused on the Si III line profiles centered on 4560 A. We searched for oscillation frequencies in different line diagnostics and find the star to be monoperiodic with frequency f=4.77153 c/d. By means of the moment method and from amplitude and phase variations across the line profiles we identified the oscillation mode of the star as radial. xi1 CMa is among the very few beta Cephei stars with a radial-velocity amplitude larger than the local speed of sound and profile variations that clearly deviate from those predicted by linear oscillation theory. [less ▲]

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See detailLine-profile variability and mass-transfer in the early type binary BD+40° 4220
Vreux, Jean-Marie ULg; Rauw, Grégor ULg; Bohannan, B. et al

in Liege International Astrophysical Colloquia (1996)

Not Available

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See detailLine-Profile Variability in the Massive Binary System HD 149404
Nazé, Yaël ULg; Carrier, Fabien; Rauw, Grégor ULg

in Interacting Winds from Massive Stars (2002)

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See detailLine-profile variablity in the spectrum of WR22 around periastron: binary interaction or intrinsic variability ?
Rauw, Grégor ULg; Vreux, Jean-Marie ULg; Gosset, Eric ULg

in Liege International Astrophysical Colloquia (1996)

Not Available

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See detailA linear accelerator for levitated micro-objects
Sari, Ibrahim; Kraft, Michael ULg

in Sensors and Actuators. A, Physical (2015)

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