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Peer Reviewed
See detailThe Impact of Complexity on Sentence Comprehension in Children with Specific Language Impairment
Leclercq, Anne-Lise ULg; Majerus, Steve ULg; Jacob, Laura et al

Poster (2012, June)

In recent years, there has been growing evidence that children with specific language impairment (SLI) show poor sentence comprehension performance. However, factors determining sentence comprehension in ... [more ▼]

In recent years, there has been growing evidence that children with specific language impairment (SLI) show poor sentence comprehension performance. However, factors determining sentence comprehension in SLI remain unclear. Limited processing capacities have been suggested as a potential cause of their syntactic problem (Ellis Weismer & Hesketh, 1996; Montgomery, 2000), but this hypothesis has not been directly addressed by manipulating inner sentence complexity. This study aims at investigating the limited capacity theory of language impairment in a sentence comprehension task, by manipulating various aspects of inner sentence complexity, as defined by the Capacity Constrained Comprehension theory (Just & Carpenter, 1992). Fifteen children with SLI, 15 age-and-IQ-matched controls, and 15 controls matched for receptive lexical and grammatical abilities performed an auditory sentence comprehension task in which lexical frequency, sentence length, and the type of relative clause (subject- or object-relativized clauses) were manipulated. Results showed a main effect of group (F(2,42)=25.40, p<.001): children with SLI performed worse than language-matched and age-matched control groups. Main effects of relative clause type (F(1,42)=198.37, p<.001) and sentence length (F(1,42)=46.29, p<.001) were also found, showing overall better performances for sentences with a subject rather than an object relative clause and for short rather than long sentences. However, the SLI group was affected to the same extent by these variables as the control groups. At the same time, a significant group-by-frequency interaction effect was found (F(2,42)=4.03, p<.05), revealing that only the SLI group showed poorer sentence comprehension performance for sentences containing low frequency words. These data confirm the severity and specificity of sentence comprehension difficulties in children with SLI (e.g., van der Lely 2005). Given that our SLI group showed impaired sentence comprehension performance relative to younger children performing at the same level on a standardized test of grammatical comprehension, it appears that processing full reversible relative clauses is especially difficult for children with specific language impairment. Moreover, SLI children’s sentence comprehension abilities are particularly affected by the presence of low frequency but familiar words, even when compared to children matched on vocabulary knowledge. [less ▲]

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See detailImpact of components of the metabolic syndrome on knee osteoarthritis progression in the SEKOIA study
Eymard, F; Edwards, M; Parsons, C et al

in Osteoarthritis and Cartilage (2014), 22(1), 376

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See detailImpact of components of the metabolic syndrome on progression of knee osteoarthritis in the SEKOIA study
Edwards, MH; Parsons, C; Eymard, F et al

in Rheumatology (2014), 53(1), 31

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See detailImpact of components of the metabolic syndrome on progression of knee osteoarthritis in the Sekoia study
Parsons, C; Edwards, MH; Eymard, F et al

in Osteoporosis International (2014), 25(2), 230

Detailed reference viewed: 12 (3 ULg)
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See detailThe impact of concomitant rhinitis on asthma-related quality of life and asthma control.
Vandenplas, O.; Dramaix, M.; Joos, G. et al

in Allergy (2010)

To cite this article: Vandenplas O, Dramaix M, Joos G, Louis R, Michils A, Verleden G, Vincken W, Vints A-M, Herbots E, Bachert C. The impact of concomitant rhinitis on asthma-related quality of life and ... [more ▼]

To cite this article: Vandenplas O, Dramaix M, Joos G, Louis R, Michils A, Verleden G, Vincken W, Vints A-M, Herbots E, Bachert C. The impact of concomitant rhinitis on asthma-related quality of life and asthma control. Allergy 2010; DOI: 10.1111/j.1398-9995.2010.02365.x. Abstract Background: Characterizing the interactions between the upper and lower airways is important for the management of asthma. This study aimed at assessing the specific impact of concomitant rhinitis on asthma-related quality of life (QOL) and asthma control. Methods: A cross-sectional, observational survey was conducted among 1173 patients with asthma (aged 12-45) recruited by general practitioners and chest physicians. AR was defined by self-reported rhinitis symptoms and previously documented sensitization to inhalant allergens. The primary outcomes were (1) asthma control assessed by the Asthma Control Questionnaire (ACQ) and (2) asthma-specific QOL evaluated through the Mini Asthma Quality of Life Questionnaire (mAQLQ). Results: AR was present in 73.9% of the population with asthma and nonallergic rhinitis (NAR) in 13.6%. AR and NAR were associated with an increased risk of uncontrolled asthma (i.e. ACQ score > 1.5) with adjusted odds ratios (OR) of 2.00 (95% confidence interval [CI]: 1.35-2.97) and 1.77 (95%CI: 1.09-2.89), respectively. Multivariate linear regression analysis showed that AR and NAR had a modest, although significant, negative impact on the global mAQLQ score (beta coefficient: -0.293, standard error [SE]: 0.063 and beta coefficient: -0.221, SE: 0.080, P < 0.001, respectively), even after adjustment for the level of asthma control and demographic characteristics. Conclusion: This survey provides direct evidence that AR and NAR are associated with an incremental adverse impact on the disease-specific QOL of patients with asthma and the level of asthma control. Further investigations are required to determine whether appropriate treatment of rhinitis would efficiently reduce asthma morbidity. [less ▲]

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See detailImpact of contaminants on thyroid and immune system of harbour porpoise (Phocoena phocoena) from the Northeast Atlantic
Das, Krishna ULg; Siebert, Ursula

Poster (2004, May)

This Marie-Curie project integrates in the research framework of transport pathway and impact of pollutant studies in the marine ecosystem and aims to understand the effects of some pollutants on the ... [more ▼]

This Marie-Curie project integrates in the research framework of transport pathway and impact of pollutant studies in the marine ecosystem and aims to understand the effects of some pollutants on the general health status, the endocrine and immune systems of the harbour porpoise (Phocoena phocoena). Pollutants such as trace metals, or organochlorines which have been recognised to have endocrine or immune disrupting effects on other species will be examined. These investigations will examine if some endocrine and immune functions are impaired by those pollutants to the extend that harbour porpoises are susceptible to infectious agents which may decrease the population size. [less ▲]

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See detailImpact of contaminated-sediment resuspension on phytoplankton in the Biguglia lagoon (Corsica, Mediterranean Sea)
Lafabrie, Céline; Garrido, Marie ULg; Leboulanger, Christophe et al

in Estuarine Coastal & Shelf Science (2013)

In shallow human-impacted systems, sediment resuspension events can result in pulsed exposures of pelagic organisms to multiple contaminants. Here, we examined the impact of the resuspension of ... [more ▼]

In shallow human-impacted systems, sediment resuspension events can result in pulsed exposures of pelagic organisms to multiple contaminants. Here, we examined the impact of the resuspension of contaminated sediment on phytoplankton in the Biguglia lagoon (Corsica, Mediterranean Sea), by conducting an in situ microcosm experiment over a 96-hour period. Natural phytoplankton was exposed to elutriates prepared from a contaminated sediment resuspension simulating process, and its functional and structural responses were compared with those of non-exposed phytoplankton. The elutriates displayed moderate multiple contamination by trace metals and PAHs. Our results show that elutriate exposure induced both functional and structural phytoplankton changes. Elutriates strongly stimulated phytoplankton growth after 24 h of exposure. They also enhanced phytoplankton photosynthetic performance during the first hours of exposure (up to 48 h), before reducing it towards the end of the experiment. Elutriates were also found to slightly stimulate Bacillariophyceae, and conversely to slightly inhibit Dinophyceae in the short term. Additionally, they stimulated phycocyanin-rich picocyanobacteria in the short term (8-48 h) before inhibiting it in the longer term (72-96 h), and to inhibit eukaryotic nanophytoplankton at short term (8-48 h) before stimulating it in the longer term (72-96 h). Sediment resuspension is thus likely to have a significant effect on the global dynamics of phytoplankton in contaminated coastal environments. [less ▲]

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See detailImpact of contamination on empirical and theoretical error
Ruwet, Christel ULg; Haesbroeck, Gentiane ULg

Conference (2009, June 18)

Classification analysis allows to group similar objects into a given number of groups by means of a classification rule. Many classification procedures are available : linear discrimination, logistic ... [more ▼]

Classification analysis allows to group similar objects into a given number of groups by means of a classification rule. Many classification procedures are available : linear discrimination, logistic discrimination, etc. Focus in this poster will be on classification resulting from a clustering analysis. Indeed, among the outputs of classical clustering techniques, a classification rule is provided in order to classify the objects into one of the clusters. More precisely, let F denote the underlying distribution and assume that the generalized kmeans algorithm with penalty function is used to construct the k clusters C1(F), . . . ,Ck(F) with centers T1(F), . . . , Tk(F). When one feels that k true groups are existing among the data, classification might be the main objective of the statistical analysis. Performance of a particular classification technique can be measured by means of an error rate. Depending on the availability of data, two types of error rates may be computed: a theoretical one and a more empirical one. In the first case, the rule is estimated on a training sample with distribution F while the evaluation of the classification performance may be done through a test sample distributed according to a model distribution of interest, Fm say. In the second case, the same data are used to set up the rule and to evaluate the performance. Under contamination, one has to replace the distribution F of the training sample by a contaminated one, F(eps) say (where eps corresponds to the fraction of contamination). In that case, thetheoretical error rate will be corrupted since it relies on a contaminated rule but it may still consider a test sample distributed according to the model distribution. The empirical error rate will be affected twice: via the rule and also via the sample used for the evaluation of the classification performance. To measure the robustness of classification based on clustering, influence functions of the error rate may be computed. The idea has already been exploited by Croux et al (2008) and Croux et al (2008) in the context of linear and logistic discrimination. In the computation of influence functions, the contaminated distribution takes the form F(eps) = (1 − eps)*Fm + eps* Dx, where Dx is the Dirac distribution putting all its mass at x. It is interesting to note that the impact of the point mass x may be positive, i.e. may decrease the error rate, when the data at hand is used to evaluate the error. [less ▲]

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See detailImpact of contamination on the TCLUST procedure
Ruwet, Christel ULg; García-Escudero, Luis Angel; Gordaliza, Alfonso et al

Conference (2011, December 18)

The TCLUST procedure is a robust clustering procedure that performs clus- tering with the aim of tting clusters with di erent scatters and weights. As the corresponding objective function can be unbounded ... [more ▼]

The TCLUST procedure is a robust clustering procedure that performs clus- tering with the aim of tting clusters with di erent scatters and weights. As the corresponding objective function can be unbounded, a restriction is added on the eigenvalues-ratio of the scatter matrices. The robustness of the method is guaranteed by allowing the trimming of a given proportion of observations. The resistance to contamination of that procedure will be studied. Results con- cerning breakdown points and some new criteria in robust cluster analysis, such as the dissolution point and the isolation robustness, will be presented. [less ▲]

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See detailImpact of contamination on training and test error rates in statistical clustering
Ruwet, Christel ULg; Haesbroeck, Gentiane ULg

in Communications in Statistics : Simulation & Computation (2011), 40(3), 394-411

The k-means algorithm is one of the most common nonhierarchical methods of clustering. It aims to construct clusters in order to minimize the within cluster sum of squared distances. However, as most ... [more ▼]

The k-means algorithm is one of the most common nonhierarchical methods of clustering. It aims to construct clusters in order to minimize the within cluster sum of squared distances. However, as most estimators defined in terms of objective functions depending on global sums of squares, the k-means procedure is not robust with respect to atypical observations in the data. Alternative techniques have thus been introduced in the literature, e.g. the k-medoids method. The k-means and k-medoids methodologies are particular cases of the generalized k-means procedure. In this paper, focus is on the error rate these clustering procedures achieve when one expects the data to be distributed according to a mixture distribution. Two different definitions of the error rate are under consideration, depending on the data at hand. It is shown that contamination may make one of these two error rates decrease even under optimal models. The consequence of this will be emphasized with the comparison of influence functions and breakdown points of these error rates. [less ▲]

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See detailImpact of contractile reserve on acute response to cardiac resynchronization therapy
Moonen, Marie ULg; Senechal, Mario; Cosyns, Bernard et al

in Cardiovascular Ultrasound (2008), 6(65),

Background: Cardiac resynchronization therapy (CRT) provides benefit for congestive heart failure, but still 30% of patients failed to respond to such therapy. This lack of response may be due to the ... [more ▼]

Background: Cardiac resynchronization therapy (CRT) provides benefit for congestive heart failure, but still 30% of patients failed to respond to such therapy. This lack of response may be due to the presence of significant amount of scar or fibrotic tissue at myocardial level. This study sought to investigate the potential impact of myocardial contractile reserve as assessed during exercise echocardiography on acute response following CRT implantation. Methods: Fifty-one consecutive patients with heart failure (LV ejection fraction 27% ± 5%, 67% ischemic cardiomyopathy) underwent exercise Doppler echocardiography before CRT implantation to assess global contractile reserve (improvement in LV ejection fraction) and local contractile reserve in the region of the LV pacing lead (assessed by radial strain using speckle tracking analysis). Responders were defined by an increase in stroke volume ≥15% after CRT. Results: Compared with nonresponders, responders (25 patients) showed a greater exercise-induced increase in LV ejection fraction, a higher degree of mitral regurgitation and a significant extent of LV dyssynchrony. The presence of contractile reserve was directly related to the acute increase in stroke volume (r = 0.48, p<0.001). Baseline myocardial deformation as well as contractile reserve in the LV pacing lead region was greater in responders during exercise than in nonresponders (p<0.0001). Conclusions: Heart failure patients referred to CRT have less chance of improving under therapy if they have no significant mitral regurgitation, no LV dyssynchrony and no contractile myocardial recruitment at exercise. [less ▲]

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See detailThe impact of corporate disclosures on information asymmetry and stock-market liquidity in France
Sougné, Danielle ULg; Ajina, Aymen ULg

Conference (2011, May 30)

This paper aims at studying the effect of the extent of disclosure on information asymmetry and stock-market liquidity in France. Our sample includes196 French listed firms over a period ranging from 2004 ... [more ▼]

This paper aims at studying the effect of the extent of disclosure on information asymmetry and stock-market liquidity in France. Our sample includes196 French listed firms over a period ranging from 2004 to 2007, the results show that the extent of disclosure in annual reports positively influence the liquidity of the French market. This is explained by the negative effect of the disclosure on the adverse selection component of the bid-ask spread. This effect is further confirmed by the commitment to IFRS by French-listed firms from 2005. This result should encourage French authorities to further improve their information environment as essential to reduce the costs of asymetric information and prevent the risk of illiquidity. [less ▲]

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See detailIMPACT OF COVER CROP AND CROP RESIDUE MANAGEMENT ON CROP PRODUCTION
Hiel, Marie-Pierre ULg; Bodson, Bernard ULg

Poster (2013, July 03)

The aim of this project is to study the crop development in relation to soil tillage and organic residue management and to understand its impact on crop production but also on the dynamics of weed ... [more ▼]

The aim of this project is to study the crop development in relation to soil tillage and organic residue management and to understand its impact on crop production but also on the dynamics of weed populations and intensity of fungal diseases occurring on the crops. Various cropping systems with different tillage methods dedicated to bury the residues from the previous crop and/or from the intercropping and to prepare the implantation of following crop are studied. [less ▲]

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See detailIMPACT OF COVER CROP MANAGEMENT ON CROP PRODUCTION: A FIELD EXPERIMENT IN WALLONIA CONTEXT
Hiel, Marie-Pierre ULg; Bodson, Bernard ULg

Poster (2014, February)

Minimal soil tillage methods, crop rotation, cover crop and continuous plant residue cover are the main pillars of sustainable agriculture. Lower energy consumption, costs and time are some direct ... [more ▼]

Minimal soil tillage methods, crop rotation, cover crop and continuous plant residue cover are the main pillars of sustainable agriculture. Lower energy consumption, costs and time are some direct benefits in favor to the adaptation of this agriculture. This practices aims also directly at protecting the soil from wind and water erosion by covering the soil. Lower disruption of the soil aims at developping the micro- and macro-fauna activity that increases soil fertility and carbon and nitrogen sequestration in soils. Unfortunately, some of the great constraints to the adaptation of conservation agriculture remain weed management, fungal diseases and pest management, that has been shown to be a problem in non-ploughed fields. The aim of our study is to evaluate, on a same field (Wallonia context), contrasted tillage methods for managing the cover crop and the implantation of the main crop. The following measurements were taken: germination rate, root and shoot biomass development, root notation (size and shape), leaf area index and quality of harvested product. Preliminary results indicate that the different tillage methods did not have a significant impact on crop production or development. However changes in germination dynamics were observed, the reduced tillage inducing slower germination. Regarding weeds populations, some difference were observed in weed occurrences. Since a field exp [less ▲]

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See detailImpact of cristallinity index on the stability and physical properties of inulin during moisture uptake.
Ronkart, Sébastien; Paquot, Michel ULg; Fougnies, C. et al

Poster (2008, April)

Detailed reference viewed: 11 (2 ULg)
See detailImpact of crops on biomass and soil carbon: steady state simulations
Nemry, B.; François, Louis ULg; Gérard, Jean-Claude ULg et al

in Cramer, W.; Doherty, R.; Hulme, M. (Eds.) et al Climate Scenarios for Agricultural, Forest and Ecosystem Impacts (2000)

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See detailImpact of cultivation practices on soil respiration
Dufranne, Delphine ULg; Vancutsem, Françoise ULg; Bodson, Bernard ULg et al

Poster (2012, February 08)

In addition to its, evident, food supply function, agriculture is subjected to various pressures and has to respond to many challenges like reducing its CO2 emissions, maintaining or improving the soil ... [more ▼]

In addition to its, evident, food supply function, agriculture is subjected to various pressures and has to respond to many challenges like reducing its CO2 emissions, maintaining or improving the soil quality, maintaining productivity, sequestrating of the carbon stock in soil... Cultivation practices are known to induce a modification of soil organic matter quantity, quality and spatial distribution, which may impact dry matter decomposition kinetics. In order to bring answers to these questions, a multidisciplinary project (SOLRESIDUS) was set up by the University of Liege, Gembloux Agro-Bio Tech in collaboration with Walloon Agricultural Research Centre (CRA-W). The aim was to investigate the impact of cultivation practices (tillage and residue restitution) on crop growth, yield and environment, as well as on soil properties and on activities. In the present study, we focused on the impacts on soil CO2 fluxes. The experimental site is situated in Gembloux, in the Belgian loamy region. The plot is divided into 4 latin squares where two tillage modalities (plough after 2 stubble breaking vs only 2 stubble breaking) and two straw management practices (restitution vs. exportation) were compared. For 3 years, soil respiration was measured with automatic and manual dynamic soil chambers. Moreover, soil respiration was measured as well in cropping zone (total respiration) as in root exclusion zones created with root exclusion cylinders (heterotrophic respiration). As first results, we observed: -a significantly higher flux in plots with residue restitution, which is clearly explained by the larger amount of organic carbon prone to decomposition; -a decrease of standardized heterotrophic respiration (linked with residue decomposition) during growing seasons; -no significant differences in soil respiration between tillage modalities after 3 growing seasons. The experiment is still in progress, more years being necessary in order to evaluate the long-term impacts of cultivation practices on soil respiration. [less ▲]

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See detailImpact of cultivation practices on soil respiration
Dufranne, Delphine ULg; Vancutsem, Françoise ULg; Bodson, Bernard ULg et al

Poster (2012, February 10)

Cultivation practices are known to induce a modification of soil organic matter quantity, quality and spatial distribution, which may impact dry matter decomposition kinetics. In order to bring answers to ... [more ▼]

Cultivation practices are known to induce a modification of soil organic matter quantity, quality and spatial distribution, which may impact dry matter decomposition kinetics. In order to bring answers to these questions, a multidisciplinary project (SOLRESIDUS) was set up by the University of Liege, Gembloux Agro-Bio Tech in collaboration with Walloon Agricultural Research Centre (CRA-W). The aim was to investigate the impact of cultivation practices (tillage and residue restitution) on crop growth, yield and environment, as well as on soil properties and on activities. In the present study, we focused on the impacts on soil respiration soil for 3 years. We will present our first results. [less ▲]

Detailed reference viewed: 28 (8 ULg)
Peer Reviewed
See detailThe impact of culture on cognitive performance in neuropsychological tests.
Schmitz, Xavier ULg; Mardaga, Julie; Meulemans, Thierry ULg

Poster (2009, September 17)

Detailed reference viewed: 20 (7 ULg)