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See detailThe impact of lateral carbon fluxes on the European carbon balance
Ciais, P.; Borges, Alberto ULg; Abril, Gwenaël et al

in Biogeosciences (2008), 5

To date, little is known about the impact of processes which cause lateral carbon fluxes over continents, and from continents to oceans on the CO2 – and carbon budgets at local, regional and continental ... [more ▼]

To date, little is known about the impact of processes which cause lateral carbon fluxes over continents, and from continents to oceans on the CO2 – and carbon budgets at local, regional and continental scales. Lateral carbon fluxes contribute to regional carbon budgets as follows: Ecosystem CO2 sink=Ecosystem carbon accumulation+Lateral carbon fluxes. We estimated the contribution of wood and food product trade, of emission and oxidation of reduced carbon species, and of river erosion and transport as lateral carbon fluxes to the carbon balance of Europe (EU-25). The analysis is completed by new estimates of the carbon fluxes of coastal seas. We estimated that lateral transport (all processes combined) is a flux of 165 Tg C yr−1 at the scale of EU-25. The magnitude of lateral transport is thus comparable to current estimates of carbon accumulation in European forests. The main process contributing to the total lateral flux out of Europe is the flux of reduced carbon compounds, corresponding to the sum of non-CO2 gaseous species (CH4, CO, hydrocarbons, . . . ) emitted by ecosystems and exported out of the European boundary layer by the large scale atmospheric circulation. [less ▲]

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See detailThe impact of lexical frequency on sentence comprehension in children with specific language impairment
Leclercq, Anne-Lise ULg; Majerus, Steve ULg; Jacob, Laura et al

in Research in Developmental Disabilities (2014), 35

Children with SLI generally exhibit poor sentence comprehension skills. We examined the specific impact of grammatical complexity and lexical frequency on comprehension performance, yielding contrasting ... [more ▼]

Children with SLI generally exhibit poor sentence comprehension skills. We examined the specific impact of grammatical complexity and lexical frequency on comprehension performance, yielding contrasting results. The present study sheds new light on sentence comprehension in children with SLI by investigating a linguistic factor which has attracted little research interest: the impact of the lexical frequency of known words on sentence comprehension. We also examined the impact of grammatical complexity and sentence length by independently varying these two factors. Fifteen children with SLI, 15 age- and IQ-matched controls, and 15 controls matched on lexical and grammatical skills, performed sentence comprehension tasks in which three linguistic factors were manipulated: lexical frequency (sentences containing words of either low or high lexical frequency), grammatical complexity (sentence containing either a subject relative clause or an object relative clause) and sentence length (either short or long sentences). Results indicated that children with SLI performed more poorly overall compared to age- and IQmatched children and to lexical and morphosyntactic age-matched children. However, their performance was not more affected by either sentence length or clause type than that of control children. Only lexical frequency affected sentence comprehension to a greater extent in children with SLI relative to the control groups, revealing that SLI children’s sentence comprehension abilities are particularly affected by the presence of lowfrequency but familiar words. [less ▲]

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See detailImpact of light and melanopsin on human cognitive brain function
Vandewalle, Gilles ULg

Conference (2015)

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See detailImpact of liming operating conditions on the convective drying kinetics of urban residual sludges
Royer, Sandrine; Blandin, Gaëtan; Salmon, Thierry ULg et al

Conference (2010, September)

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See detailImpact of liquid droplets on granular media
Delon, Giles ULg; Terwagne, Denis ULg; Dorbolo, Stéphane ULg et al

in Physical Review. E : Statistical, Nonlinear, and Soft Matter Physics (2011)

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See detailImpact of liquidity constraint on the management of animal genetic resources by pastoralist herders.
Antoine-Moussiaux, Nicolas ULg

Conference (2011, April 27)

The improvement of pastoral livelihoods in the context of a highly uncertain economic and climatic future implies a double need for conserving livestock biodiversity and reaching productivity gains. In ... [more ▼]

The improvement of pastoral livelihoods in the context of a highly uncertain economic and climatic future implies a double need for conserving livestock biodiversity and reaching productivity gains. In situ conservation through participative genetic improvement programs is a tool of choice for these sustainable development pursuits. In this regard, selection criteria chosen by pastoralist breeders can be classified in two broad categories : productivity-seeking or risk-alleviating. The latter aim was an important motive for the constitution of the present indigenous breeds while the former is often a rationale for their neglect. Understanding the balance can help finding the way to sustainable biodiversity management. As the basis of pastoral livelihood systems, livestock shoulders many roles, among which that of savings may be considered central. Credit facilities lacking in these remote areas, breeders would thus sell part of their productive capital to invest in its improvement. The present model consists in a theoretical inquiry for the possible consequence of this polyvalence of livestock, productive capital and mobilizable saving, on the choice between the two above-mentioned breeding aims under liquidity constraint. A major outcome of the proposed model is the existence of a threshold herd size effect on investment in risk-control. This effect does not bear on investment in productivity and is no longer observed if credit constraint is relaxed. This threshold is thus proposed to entail the presence of an “erosion trap” for biodiversity and further recalls the difficulty to design a breeding program for a group of breeders with very diverse endowments. As a result, appropriate credit programs should be considered as an important key to adoption of breeding schemes for in situ conservation, and thus both their efficiency and viability. [less ▲]

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See detailImpact of low frequency transcranial magnetic stimulation on event-related brain potentials.
Hansenne, Michel ULg; Laloyaux, Olivier ULg; Mardaga, Solange et al

in Biological Psychology (2004), 67(3), 331-41

Contradictory findings exist concerning the inhibitory function of low frequency repetitive transcranial magnetic stimulation (rTMS). Therefore, the study examines the impact of different duration of low ... [more ▼]

Contradictory findings exist concerning the inhibitory function of low frequency repetitive transcranial magnetic stimulation (rTMS). Therefore, the study examines the impact of different duration of low frequency rTMS on ERPs. In 17 subjects, auditory ERPs were measured before and after 1 Hz rTMS delivered over the left prefrontal cortex during 10 min (600 pulses) and 15 min (900 pulses). Results showed that 15 min of 1 Hz rTMS induced a significant increase of P300 latency. There was no effect for early ERP components (N100, P200 and N200). This study confirms and extends that 1 Hz rTMS produces a real inhibitory effect only when the duration of the stimulation is about 15 min. The data suggest that rTMS modifies the speed of cognitive processing rather than the energetical aspect of information processing, and that cortical inhibition induced by the magnetic stimulation affects principally the controlled cognitive processes and not the automatic ones. [less ▲]

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See detailImpact of low-frequency transcranial magnetic stimulation on brain automatic information processing - A mismatch negativity study
Laloyaux, Olivier ULg; Ansseau, Marc ULg; Hansenne, Michel ULg

in Journal of Psychophysiology (2006), 20(4), 267-275

Repetitive transcranial magnetic stimulation (rTMS) is considered a powerful method for the study of the relationships between cortical activity and-cognitive processes. Previous ERPs studies' that ... [more ▼]

Repetitive transcranial magnetic stimulation (rTMS) is considered a powerful method for the study of the relationships between cortical activity and-cognitive processes. Previous ERPs studies' that focused on P300 response have shown that inhibitory/excitatory effects on prefrontal cortex (PFC), induced by low- and high-frequency rTMS, were able to modulate controlled but not automatic information processing. The present study assessed the impact of inhibition over left and right PFC induced by rTMS on mismatch negativity (MMN), which is known to represent automatic cerebral processes for detecting change. Auditory MMN was recorded in 20 subjects before and after application of left and right PFC 1-Hz rTMS for 15 min. MMN was also recorded before and after a sham-occipital 1-Hz rTMS as control condition. Results showed that 1-Hz rTMS induced no modification to either MMN latency or amplitude. In addition, N100 and P200 components to the frequent tones were not affected by rTMS. These results are consistent with previous findings showing that rTMS; over both PFC is unable to disrupt automatic information processing. However, since two sites were stimulated in the present-study, no definite conclusions about the inability of rTMS to disrupt automatic processing can be made. [less ▲]

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See detailImpact of M. fijiensis metabolites on banana antioxidant systems
Busogoro, J. P.; Lepoivre, Philippe ULg; Etame, J. J. et al

Conference (2004)

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See detailImpact of medical specialist' locus of control on communication skills in oncological interviews
Libert, Y.; Janne, P.; Razavi, D. et al

in British Journal of Cancer (2003), 88

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See detailImpact of medical therapies on inflammatory bowel disease complication rate.
REENAERS, Catherine ULg; Belaiche, Jacques ULg; Louis, Edouard ULg

in World Journal of Gastroenterology (2012), 18(29), 3823-7

Crohn's disease and ulcerative colitis are progressive diseases associated with a high risk of complications over time including strictures, fistulae, perianal complications, surgery, and colorectal ... [more ▼]

Crohn's disease and ulcerative colitis are progressive diseases associated with a high risk of complications over time including strictures, fistulae, perianal complications, surgery, and colorectal cancer. Changing the natural history and avoiding evolution to a disabling disease should be the main goal of treatment. In recent studies, mucosal healing has been associated with longer-term remission and fewer complications. Conventional therapies with immunosuppressive drugs are able to induce mucosal healing in a minority of cases but their impact on disease progression appears modest. Higher rates of mucosal healing can be achieved with anti-tumor necrosis factor therapies that reduce the risk of relapse, surgery and hospitalization, and are associated with perianal fistulae closure. These drugs might be able to change the natural history of the disease mainly when introduced early in the course of the disease. Treatment strategy in inflammatory bowel diseases should thus be tailored according to the risk that each patient could develop disabling disease. [less ▲]

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See detailImpact of medication non-compliance and non-persistence on pharmacoeconomic evaluations in osteoporosis
Hiligsmann, Mickaël ULg; Rabenda, Véronique ULg; Gathon, Henry-Jean ULg et al

in Osteoporosis International (2008, December), 19(S2), 282

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See detailImpact of metallurgical size effects on plasticity of thin metallic materials
Hug, Eric; keller, clement; Habraken, Anne ULg

in Materials Science Forum (2014), 783-786

Three examples involving size effects are presented witj implications concerning the formability: small Ni-20wt.%Cr resistive bridges, magnetic micro-sensors performed with (Ni,Co,Fe)based alloys and ... [more ▼]

Three examples involving size effects are presented witj implications concerning the formability: small Ni-20wt.%Cr resistive bridges, magnetic micro-sensors performed with (Ni,Co,Fe)based alloys and copper clad aluminum thin wires. The mechanical properties are directly linked to the ratio thickness over grain size (t/d ratio) of the parts.These metallurgical considerations must be taken into account when we are concerned by numerical simulation of the process of such components. It is shown that the simulations can correctly reproduce the softening effect linked to a decrease in thickness and in number of grains across the thickness. Finally the effect of a moderate increase in temperature on these results will be briefly reported. [less ▲]

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See detailImpact of micro-physics and macro-physics on the seismic properties of main-sequence B-type stars
Salmon, Sébastien ULg

Doctoral thesis (2014)

L’étude des pulsations stellaires, tout comme les ondes sismiques sur Terre, nous donne une méthode puissante afin de découvrir l’intérieur des étoiles. Cette discipline scientifique est aussi connue sous ... [more ▼]

L’étude des pulsations stellaires, tout comme les ondes sismiques sur Terre, nous donne une méthode puissante afin de découvrir l’intérieur des étoiles. Cette discipline scientifique est aussi connue sous le nom d’astérosismologie. Grâce aux missions spatiales CoRoT et Kepler, l’astérosismologie est entrée depuis dans une période faste. Par ailleurs, une frac- tion significative des étoiles présente des pulsations, ce qui nous permet de sonder leur intérieur pour la plupart de leurs stades d’évolution. Cette thèse se concentre sur les étoiles de type B de la séquence principale. Via l’inter- action de leurs vents stellaires avec leur milieu environnant et la production de nouveaux éléments chimiques en leurs intérieurs, elles contribuent aux processus dynamiques et d’enrichissement chimique du milieu interstellaire. Heureusement, deux types de pulsa- tion stellaire affectent ces étoiles: d’une part les pulsations dites de type β Cephei et d’autre part celles de type SPB. La nature de ces pulsations est sensible aux processus physiques internes de ces étoiles. Ainsi, l’observation de ces pulsations nous offre de sonder ces différents processus. Dans cette thèse, nous étudions tout particulièrement la sensibilité de ces étoiles aux opacités ra- diatives, et nous appuyant sur ces résultats, contraignons l’opacité radiative des éléments du groupe du fer à l’aide des étoiles pulsantes repérées dans les Nuages de Magellan. Dans une seconde étape, nous évaluons la possibilité de contraindre la nature du mélan- ge (diffusif ou overshooting instantané) à l’aide de la modélisation des β Cephei par l’ap- proche directe. Nous testons également les facteurs influençant la détermination de l’exten- sion de la zone mélangée. Enfin, nous proposons un scénario explicatif de la récente découverte d’une nouvelle classe d’étoiles variables dans un amas stellaire connu pour comporter de nombreuses étoiles en rotation rapide. [less ▲]

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See detailImpact of microbial activities on the mineralogy and performance of column-scale permeable reactive iron barriers operated under two different redox conditions
Van Nooten, Thomas; Lieben, François; Dries, Jan et al

in Environmental Science & Technology (2007), 41(16), 5724-5730

The present study focuses on the impact of microbial activities on the performance of various long-term operated laboratory-scale permeable reactive barriers. The barriers contained both aquifer and Fe-0 ... [more ▼]

The present study focuses on the impact of microbial activities on the performance of various long-term operated laboratory-scale permeable reactive barriers. The barriers contained both aquifer and Fe-0 compartments and had received either sulfate or iron(Ill)-EDTAto promote sulfatereducing and iron(Ill)-reducing bacteria, respectively. After dismantlement of the compartments after almost 3 years of operation, DNA-based PCR-DGGE analysis revealed the presence of methanogenic, sulfate-reducing, metalreducing, and denitrifying bacteria within as well as up- and downgradient of the Fe-0 matrix. Under all imposed conditions, the main secondary phases were vivianite, siderite, ferrous hydroxy carbonate, and carbonate green rust as found by scanning electron microscopy (SEM) combined with energy dispersive X-ray analysis (EDX), and X-ray diffraction (XRD). Under sulfate-reduction promoting conditions, iron sulfides were formed in addition, resulting in 7 and 10 times higher degradation rates for PCE and TICE, respectively, compared to unreacted iron. These results indicate that the presence of sulfate-reducing bacteria in or around iron barriers and the subsequent formation of iron sulfides might increase the barrier reactivity. [less ▲]

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See detailImpact of microbiological processes on the cycling of Fe in Antarctic sea-ice during Spring
Schoemann, Véronique; Lannuzel, Delphine; Becquevort, Sylvie et al

Poster (2006, February)

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See detailImpact of Missing Data on Phylogenies Inferred from Empirical Phylogenomic Data Sets
Roure, Béatrice; Baurain, Denis ULg; Philippe, Hervé

in Molecular Biology and Evolution (2013), 30(1), 197-214

Progress in sequencing technology allows researchers to assemble ever-larger supermatrices for phylogenomic inference. However, current phylogenomic studies often rest on patchy data sets, with some ... [more ▼]

Progress in sequencing technology allows researchers to assemble ever-larger supermatrices for phylogenomic inference. However, current phylogenomic studies often rest on patchy data sets, with some having 80% missing (or ambiguous) data or more. Though early simulations had suggested that missing data per se do not harm phylogenetic inference when using sufficiently large data sets, Lemmon et al. (Lemmon AR, Brown JM, Stanger-Hall K, Lemmon EM. 2009. The effect of ambiguous data on phylogenetic estimates obtained by maximum likelihood and Bayesian inference. Syst Biol. 58:130-145.) have recently cast doubt on this consensus in a study based on the introduction of parsimony-uninformative incomplete characters. In this work, we empirically reassess the issue of missing data in phylogenomics while exploring possible interactions with the model of sequence evolution. First, we note that parsimony-uninformative incomplete characters are actually informative in a probabilistic framework. A reanalysis of Lemmon's data set with this in mind gives a very different interpretation of their results and shows that some of their conclusions may be unfounded. Second, we investigate the effect of the progressive introduction of missing data in a complete supermatrix (126 genes × 39 species) capable of resolving animal relationships. These analyses demonstrate that missing data perturb phylogenetic inference slightly beyond the expected decrease in resolving power. In particular, they exacerbate systematic errors by reducing the number of species effectively available for the detection of multiple substitutions. Consequently, large sparse supermatrices are more sensitive to phylogenetic artifacts than smaller but less incomplete data sets, which argue for experimental designs aimed at collecting a modest number (∼50) of highly covered genes. Our results further confirm that including incomplete yet short-branch taxa (i.e., slowly evolving species or close outgroups) can help to eschew artifacts, as predicted by simulations. Finally, it appears that selecting an adequate model of sequence evolution (e.g., the site-heterogeneous CAT model instead of the site-homogeneous WAG model) is more beneficial to phylogenetic accuracy than reducing the level of missing data. [less ▲]

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See detailImpact of mitral regurgitation and myocardial viability on left ventricular reverse remodeling after cardiac resynchronization therapy in patients with ischemic cardiomyopathy.
Senechal, Mario; Lancellotti, Patrizio ULg; Magne, Julien ULg et al

in American Journal of Cardiology (2010), 106(1), 31-7

This study investigated the impact of ischemic mitral regurgitation (MR) severity and viability on left ventricular (LV) reverse remodeling after cardiac resynchronization therapy (CRT) in patients with ... [more ▼]

This study investigated the impact of ischemic mitral regurgitation (MR) severity and viability on left ventricular (LV) reverse remodeling after cardiac resynchronization therapy (CRT) in patients with ischemic cardiomyopathy. Severe MR and ischemic cardiomyopathy have been associated with lack of LV reverse remodeling after CRT. Fifty-seven consecutive patients with ischemic MR, LV ejection fraction < or =35%, QRS duration > or =120 ms, and intraventricular dyssynchrony > or =50 ms were prospectively included. Stress echocardiography was performed before CRT implantation. Viability in the region of the LV pacing lead was defined as the presence of viability in 2 contiguous segments. Response to CRT at 6 months was defined by evidence of > or =15% LV decrease in end-systolic volume. Severe MR was defined by an effective regurgitant orifice (ERO) area > or =20 mm(2). Thirty-three patients (58%) were responders at follow-up. Baseline ERO area and prevalence of severe MR were not different between responders and nonresponders (19 +/- 11 vs 21 +/- 13 mm(2), p = 0.67; 52% vs 53%, p = 0.84). In responders, MR was decreased by 58% (ERO 19 +/- 12 to 8 +/- 6 mm(2)). In the presence of viability in the region of the pacing lead, 74% (n = 29 patients) were responders (sensitivity 88%, specificity 58%); in the subgroup of patients with viability in the region of the pacing lead and severe MR, 83% (n = 17 patients) were responders. In conclusion, LV remodeling is frequent and ischemic MR decrease important in patients with viability in the region of the pacing lead without regard to MR severity. [less ▲]

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