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See detailInfluence of noise correction on intra- and inter-subject variability of quantitative metrics in diffusion kurtosis imaging
André, Elodie ULg; Grinberg, Farida; Farrher, Ezequiel et al

in PLoS ONE (in press)

Diffusion kurtosis imaging (DKI) is a promising extension of diffusion tensor imaging, giving new insights into the white matter microstructure and providing new biomarkers. Given the rapidly increasing ... [more ▼]

Diffusion kurtosis imaging (DKI) is a promising extension of diffusion tensor imaging, giving new insights into the white matter microstructure and providing new biomarkers. Given the rapidly increasing number of studies, DKI has a potential to establish itself as a valuable tool in brain diagnostics. However, to become a routine procedure, DKI still needs to be improved in terms of robustness, reliability, and reproducibility. As it requires acquisitions at higher diffusion31 weightings, results are more affected by noise than in diffusion tensor imaging. The lack of standard procedures for post-processing, especially for noise correction, might become a significant obstacle for the use of DKI in clinical routine limiting its application. We considered two noise correction schemes accounting for the noise properties of multichannel phased-array coils, in order to improve the data quality at signal-to-noise ratio (SNR) typical for DKI. The SNR dependence of estimated DKI metrics such as mean kurtosis (MK), mean diffusivity (MD) and fractional anisotropy (FA) is investigated for these noise correction approaches in Monte Carlo simulations and in in vivo human studies. The intra-subject reproducibility is investigated in a single subject study by varying the SNR level and SNR spatial distribution. Then the impact of the noise correction on inter-subject variability is evaluated in a homogeneous sample of 25 healthy volunteers. Results show a strong impact of noise correction on the MK estimate, while the estimation of FA and MD was affected to a lesser extent. Both intra- and inter-subject SNR related variability of the MK estimate is considerably reduced after correction for the noise bias, providing more accurate and reproducible measures. In this work, we have proposed a straightforward method that improves accuracy of DKI metrics. This should contribute to standardization of DKI applications in clinical studies and making valuable inferences in group analysis and longitudinal studies. [less ▲]

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See detailInfluence of non-adiabatic temperature variations on line profile variations of slowly rotating beta Cep stars and SPBs. I. Non-adiabatic eigenfunctions in the atmosphere of a pulsating star
Dupret, Marc-Antoine ULg; De Ridder, J.; Neuforge, C. et al

in Astronomy and Astrophysics (2002), 385

In this study, we compute theoretical line profiles of a non-radially pulsating star, taking the non-adiabatic effects into account. These non-adiabatic effects are especially important in the atmosphere ... [more ▼]

In this study, we compute theoretical line profiles of a non-radially pulsating star, taking the non-adiabatic effects into account. These non-adiabatic effects are especially important in the atmosphere, where the spectral lines are formed, and must be accounted for. In this first paper of the series, we present a new treatment of the perturbed thermal and dynamical equations in the atmosphere of a pulsating star. We apply our formalism to the computation of non-adiabatic eigenfunctions in a typical beta Cephei star with low order p-modes and in a typical slowly pulsating B star with high-order g-modes. [less ▲]

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See detailInfluence of non-adiabatic temperature variations on line profile variations of slowly rotating beta Cephei stars and SPBs. II. Simulations of line profile time series
De Ridder, J.; Dupret, Marc-Antoine ULg; Neuforge, C. et al

in Astronomy and Astrophysics (2002), 385

We investigate to what extent non-adiabatic temperature variations at the surface of slowly rotating non-radially pulsating beta Cephei stars and slowly pulsating B stars affect silicon line profile ... [more ▼]

We investigate to what extent non-adiabatic temperature variations at the surface of slowly rotating non-radially pulsating beta Cephei stars and slowly pulsating B stars affect silicon line profile variations. We use the non-adiabatic amplitudes of the effective temperature and gravity variation presented in Dupret et al. (\cite{Dupret02}), together with a Kurucz intensity grid, to compute time series of line profile variations. Our simulations point out that the line shapes do not change significantly due to temperature variations. We find equivalent width variations of at most two percent of the mean equivalent width. We confront our results with observational equivalent width variations and with photometrically obtained effective temperature variations. Based on observations obtained with the Swiss photometric telescope and with the ESO/CAT telescope, at La Silla in Chile. [less ▲]

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See detailInfluence of nonlocal electrodynamics on the anisotropic vortex pinning in YNi2B2C
Silhanek, Alejandro ULg; Thompson, J. R.; Civale, L. et al

in Physical Review. B : Condensed Matter (2001), 64(1),

We have studied the pinning force density F-p of YNi2B2C superconductors for various field orientations. We observe anisotropies both between the c axis and the basal plane and within the plane that ... [more ▼]

We have studied the pinning force density F-p of YNi2B2C superconductors for various field orientations. We observe anisotropies both between the c axis and the basal plane and within the plane that cannot be explained by the usual mass anisotropy. For magnetic field H parallel toc, the reorientation structural transition in the vortex lattice due to nonlocality, which occurs at a field H(1)similar to1 kOe, manifests itself as a kink in F-p(H). When H perpendicular toc, F-p is much larger and has a quite different H dependence, indicating that other pinning mechanisms are present. In this case the signature of nonlocal effects is the presence of a fourfold periodicity of F-p within the basal plane. [less ▲]

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See detailInfluence of nuclear de-excitation on observables relevant for space exploration
Mancusi, Davide ULg; Boudard, Alain; Cugnon, Joseph ULg et al

in Advances in Space Research (2011), 47(7), 1194-1199

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See detailInfluence of nutraceuticals on cartilage health and integrity
Henrotin, Yves ULg; Mathy-Hartet, M; Reginster, Jean-Yves ULg

in Proceeding of the Large Breed Health Care Symposium (2001)

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See detailInfluence of nutrition on meat quality in double muscled bulls
Van Vooren, Tom; Van Hoof, Jan; Vereecke, D. et al

in 38th International Congress of Meat Science Technology (1992)

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See detailInfluence of obesity on plasma lipid and lipoprotein concentrations in dogs.
Jeusette, Isabelle C; Lhoest, Estelle T; Istasse, Louis ULg et al

in American Journal of Veterinary Research (2005), 66(1), 81-6

OBJECTIVE: To determine effects of obesity and diet in dogs on plasma lipid and lipoprotein concentrations by assaying plasma leptin and ghrelin concentrations and determining total plasma cholesterol and ... [more ▼]

OBJECTIVE: To determine effects of obesity and diet in dogs on plasma lipid and lipoprotein concentrations by assaying plasma leptin and ghrelin concentrations and determining total plasma cholesterol and triglyceride concentrations as well as the concentrations of cholesterol and triglycerides in various lipoprotein classes (ie, very-low-density, low-density, and high-density lipoproteins). ANIMALS: 24 Beagles; 12 lean (mean [+/- SEM] body weight, 12.7 +/- 0.7 kg) and 12 chronically obese (21.9 +/- 0.8 kg) dogs of both sexes, between 1 and 9 years old. PROCEDURES: Total plasma cholesterol and triglyceride concentrations; lipoprotein cholesterol and triglyceride concentrations; and plasma ghrelin, leptin, free fatty acids, insulin, and glucose concentrations were measured and compared between lean and obese dogs, both of which were fed a complete and balanced maintenance diet. Chronically obese dogs were subsequently fed a high-protein low-energy diet to evaluate effects of diet composition on plasma lipid and lipoprotein measurements. RESULTS: Chronic obesity resulted in a significant decrease in plasma ghrelin concentration and a significant increase in plasma leptin, cholesterol, and triglyceride concentrations in dogs. High total plasma cholesterol and triglyceride concentrations resulted from increased cholesterol and triglyceride concentrations in all lipoprotein fractions. In obese dogs, modification of diet composition resulted in beneficial effects on plasma lipid and leptin concentrations, even before weight loss was observed. CONCLUSIONS AND CLINICAL RELEVANCE: Correlations exist between obesity and plasma measurements (ie, lipoproteins, leptin, insulin, and ghrelin) commonly associated with obesity. Modification of diet composition to control energy intake improves plasma lipid and leptin concentrations in obese dogs. [less ▲]

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See detailThe influence of occupation modes on building heating loads: the case of a detached house located in a suburban area
de Meester, Tatiana; Marique, Anne-Françoise ULg; Reiter, Sigrid ULg

in Evrard Arnaud, Bodard Magali (Ed.) PLEA 2011 Architecture & Sustainable Development, Proceedings (2011, July)

Occupants’ behaviour is known to have a great influence on energetic demand, management and consumptions of a building. However, parameters related to inhabitants’ lifestyle are often neglected in ... [more ▼]

Occupants’ behaviour is known to have a great influence on energetic demand, management and consumptions of a building. However, parameters related to inhabitants’ lifestyle are often neglected in energetic studies and researches that often focus on insulation, ventilation or climate. In this context, the aim of the paper is to investigate the influence of three parameters related to human behaviour (the family size and the modes of occupations, the management of the heating system and the management of the heated area) on the housing heating loads of a standard dwelling. The case study chosen for this analysis is a detached house located in a suburban area. Five levels of insulation are tested (no insulation, an intermediate level corresponding to 3 cm of insulation, the current standard for new buildings in the Walloon region of Belgium, the low energy standard and the passive house standard) in order to highlight the impact and the interactions between occupation modes and insulation levels. The relevance of the adaptation of the living area of the house according to the evolution of the family size is finally discussed. [less ▲]

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See detailInfluence of one-line vegetation on the edge of the floodplain on velocity and boundary shear stress distributions in compound channel
Terrier, B.; Peltier, Yann ULg; Shiono, K. et al

in 34th IAHR Congr.: Balance and Uncertainty; Water in a Changing World (2011)

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See detailInfluence of opacities, partition functions and hydrogen diffusion on the 5 min solar oscillations
Gabriel, Maurice ULg; Noels-Grötsch, Arlette ULg; Scuflaire, Richard ULg

in Memorie della Società Astronomica Italiana : Journal of the Italian Astronomical Society (1984), 55(1-2), 169-174

Several accuracy tests of the frequencies computation have been performed. They show that for a given model, the frequencies have errors lower than 2 micro-Hz. Several tests have also been made on the ... [more ▼]

Several accuracy tests of the frequencies computation have been performed. They show that for a given model, the frequencies have errors lower than 2 micro-Hz. Several tests have also been made on the Henyey code. They show that the use of the same opacity formula as Bahcall et al. (1983) allows to reproduce their model with a good accuracy. The model has however frequencies systematically 12 micro-Hz larger than found by Ulrich and Rhodes. A model with diffusion of H and He has also been studied. Its frequencies are nearly the same as those of the standard model. [less ▲]

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See detailInfluence of OPD control on a ground-based nulling interferometer
Absil, Olivier ULg

Scientific conference (2002, August 25)

Atmospheric turbulence is a major source of noise in any fiber-linked interferometer through the piston effect which induces an erratic movement of the fringes. Because the stellar light has to be ... [more ▼]

Atmospheric turbulence is a major source of noise in any fiber-linked interferometer through the piston effect which induces an erratic movement of the fringes. Because the stellar light has to be constantly cancelled by the central dark fringe, a ground-based nulling interferometer is not possible without stringent OPD control. In this paper, we investigate the influence of the residual OPD error of a fringe tracking unit on the performances of a nulling interferometer. This influence strongly depends on the aperture configuration of the interferometer. Even with the most robust configurations, the detection of exo-zodiacal clouds similar to ours around nearby main sequence stars is not possible if the residual OPD error exceeds 15 nanometers rms. This specification can only be reached if the fringe tracker is optimized for bright sources. [less ▲]

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See detailInfluence of operating conditions on the gaseous emissions related to urban residual sludge convective drying
Fraikin, Laurent ULg; Herbreteau, Benjamin; Chaucherie, Xavier et al

Poster (2010)

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See detailInfluence of operating parameters on nitrite
Kouakou, Edouard; Salmon, Thierry ULg; Marchot, Pierre ULg et al

in Proceeding of the International Symposium on Environmental Biotechnology (2006)

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See detailInfluence of optical path delay control on a ground-based nulling interferometer
Absil, Olivier ULg; Coude du Foresto, Vincent

in Traub, Wesley (Ed.) Interferometry for Optical Astronomy II (2003, February 01)

Atmospheric turbulence is a major source of noise in any fiber-linked interferometer through the piston effect between the two arms of the interferometer which induces an erratic movement of the fringes ... [more ▼]

Atmospheric turbulence is a major source of noise in any fiber-linked interferometer through the piston effect between the two arms of the interferometer which induces an erratic movement of the fringes. Because the stellar light has to be permanently cancelled by the central dark fringe, a ground-based nulling interferometer is not possible without stringent optical path delay (OPD) control. In this paper, we investigate the influence of the residual OPD error of a fringe tracking unit on the performances of a nulling interferometer. The accuracy required for this control system strongly depends on the observation wavelength. If we want to detect exozodiacal clouds ten times as dense as our zodiacal dust cloud in the near-infrared (L' band), the performances of the fringe tracker are crucial: the residual OPD should be about 20 nanometers RMS. This specification can only be reached if the fringe sensor is optimized for bright sources. In the mid-infrared (N band), the requirements are strongly relaxed: OPD control with an accuracy of 400 nm RMS is sufficient to be background-limited, but a lower residual OPD (about 50 nm RMS) is strongly recommended to reduce the stellar leakage. [less ▲]

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See detailInfluence of oral contraceptives and pregnancy on constituents of the kallikrein-kininogen system in plasma.
Adam, Albert; Albert, Adelin ULg; BOULANGER, Josianne ULg et al

in Clinical Chemistry (1985), 31(9), 1533-6

We measured kininogens of low and high molecular mass along with prokallikrein activity in plasma of women with a normal menstrual cycle. We observed no difference between results for the follicular and ... [more ▼]

We measured kininogens of low and high molecular mass along with prokallikrein activity in plasma of women with a normal menstrual cycle. We observed no difference between results for the follicular and luteal phases. We assayed the same constituents in women who were taking oral contraceptives (combined estroprogestative) and found that activity of prokallikrein and concentrations of low- and high-molecular-mass kininogens were significantly increased. Lastly, we studied the components of the kallikrein-kininogen system during pregnancy. We also observed a marked increase in their concentrations in plasma, despite a decrease in total proteins. Specifically, prokallikrein and kininogens increase continuously with gestational age, reaching their maxima around the eighth month of pregnancy. At that time, more than 50% of observed results fall outside the normal reference interval. Our observations are even more striking when prokallikrein and kininogens are expressed in units per gram of total proteins, to account for the hemodilution. After delivery, the concentrations of prokallikrein and low- and high-molecular-mass kininogens decline promptly, returning to normal within three days. [less ▲]

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See detailInfluence of organic matter on bio-availability of carbosulfan and its toxicity on a carabidae
Hautier, L.; Jansen, J. P.; Mabon, N. et al

in Abstracts - 59the International Symposium on Crop Protection (2007, May 22)

Detailed reference viewed: 29 (8 ULg)