How did endemic cyprinids and exotic european catfish move in a large river ecosystem?
; ; Ovidio, Michaël
Conference (2013, October 03)Detailed reference viewed: 8 (0 ULg)
How do auditory verbal hallucinations in patients differ from those in nonpatients?
in Frontiers in Human Neuroscience (2012), 6Detailed reference viewed: 13 (2 ULg)
How do climate warming and plant species richness affect water use in experimental grasslands?
; ; et al
in Plant and Soil (2006), 288
Climate warming and plant species richness loss have been the subject of numerous experiments, but studies on their combined impact are lacking. Here we studied how both warming and species richness loss ... [more ▼]
Climate warming and plant species richness loss have been the subject of numerous experiments, but studies on their combined impact are lacking. Here we studied how both warming and species richness loss affect water use in grasslands, while identifying interactions between these global changes. Experimental ecosystems containing one, three or nine grassland species from three functional groups were grown in 12 sunlit, climate-controlled chambers (2.25 m(2) ground area) in Wilrijk, Belgium. Half of these chambers were exposed to ambient air temperatures (unheated), while the other half were warmed by 3 degrees C (heated). Equal amounts of water were added to heated and unheated communities, so that warming would imply drier soils if evapotranspiration (ET) was higher. After an initial ET increase in response to warming, stomatal regulation and lower above-ground productivity resulted in ET values comparable with those recorded in the unheated communities. As a result of the decreased biomass production, water use efficiency (WUE) was reduced by warming. Higher complementarity and the improved competitive success of water-efficient species in mixtures led to an increased WUE in multi-species communities as compared to monocultures, regardless of the induced warming. However, since the WUE of individual species was affected in different ways by higher temperatures, compositional changes in mixtures seem likely under climatic change due to shifts in competitiveness. In conclusion, while increased complementarity and selection of water-efficient species ensured more efficient water use in mixtures than monocultures, global warming will likely decrease this WUE, and this may be most pronounced in species-rich communities. [less ▲]Detailed reference viewed: 47 (5 ULg)
How do climate warming, plant species richness and plant functional group affect ammonia oxidizing bacteria diversity and function in experimental grasslands?
Malchair, Sandrine ; Carnol, Monique
Poster (2011, June 27)
How do climate warming, plant species richness and plant functional group affect ammonia oxidizing bacteria diversity and function in experimental grasslands? Malchair S. and Carnol M. Laboratory of Plant ... [more ▼]
How do climate warming, plant species richness and plant functional group affect ammonia oxidizing bacteria diversity and function in experimental grasslands? Malchair S. and Carnol M. Laboratory of Plant and Microbial Ecology Department of Sciences and Environmental Management University of Liege, Belgium Background: There is increasing evidence of diversity-function relationship and impact of warming for aboveground vegetation. Belowground effects of warming and plant species richness remain however largely unknown, although bacteria regulate many soil processes and some groups, like ammonia oxidizing bacteria (AOB) were, have been suggested highly sensitive to environmental stress. Objectives: 1. Investigation of the response of AOB richness, community composition and function to warming, plant species richness and functional group 2. Exploration of the AOB richness-function link Methods: Soil samples were taken at 2 depths from grassland model ecosystems with different species richness levels (1, 3, 9) and temperature treatments (ambient, ambient+3°C). Selected species belonged to 3 plant functional groups: forbs, legumes and grasses. AOB function: potential nitrification assay (shaken soil slurry method) AOB diversity: polymerase chain reaction followed by denaturing gradient gel electrophoresis (PCR-DGGE) Results: 1. All retrieved AOB sequences were Nitrosospira-like ones 2. Warming had no effect on AOB richness and function 3. Higher plant species richness leads to increased AOB richness and modified community structure. AOB function was increased only at lower depth under warming 4. No difference in AOB richness between the plant functional groups 5. AOB community structure was different and AOB function higher under legumes. 6. The AOB richness-function link was negative under legumes. Conclusions: 1. Plant species influenced AOB richness and community composition. Plant functional group seems to be more important that species richness. 2. Legumes may impact AOB diversity and function through ammonia availability. [less ▲]Detailed reference viewed: 35 (2 ULg)
How do CSR Standards Affect Stakeholder Management? An Integrative Framework Grounded in Pratice
El Abboubi, Manal ; Cornet, Annie
Conference (2010)Detailed reference viewed: 29 (6 ULg)
How do education systems care of low engaged readers ? Institutional and socioeconomic factors influencing the reading engagement
Baye, Ariane ; Monseur, Christian ; Lafontaine, Dominique
Conference (2009, September)Detailed reference viewed: 9 (2 ULg)
How do Foreigners and Immigrants in Belgium View the Legal System ?
Martiniello, Marco ; ; et al
in Journal of Immigration, Asylum and Nationality Law (2007), 21(4), 263-283Detailed reference viewed: 51 (3 ULg)
How do ladybirds and syrphids respond to aphids in the field?
; Doucet, Jean-Louis ;
in Bulletin OILB/SROP = IOBC/WPRS Bulletin (1994), 17(4),Detailed reference viewed: 13 (2 ULg)
How do music experts and non-experts evaluate the vocal accuracy of operatic singing voices?
Larrouy, Pauline ; ; Morsomme, Dominique
Conference (2013, August 22)
Professional singers are expected to sing in tune. However, when an operatic singing technique is employed, the objective measurement of the vocal accuracy (i.e. pitch interval deviation) shows ... [more ▼]
Professional singers are expected to sing in tune. However, when an operatic singing technique is employed, the objective measurement of the vocal accuracy (i.e. pitch interval deviation) shows particularly low scores, whatever the melody performed. This study focuses on the perceptual judgment of operatic voices in order to observe the evaluation process of singing voice accuracy by music experts and non-experts. In addition, this study aims to better understand the relationship between the subjective and objective measurements of operatic singing voices. 22 music experts and 22 non-experts paired in age and gender participated in a test and a retest (8 to 15 days in between). Fourteen sung performances performed by professional operatic singers were presented with a pairwise comparison paradigm. The participants were asked to indicate the most “in tune” melody for each pair (N = 91). The performances obtained thus a ranking by each judge. In addition, the 14 sung performances were objectively analyzed in order to confront the objective measurement of singing voice accuracy with the perceptual rating of the judges. Computing the variances of rank differences between the test and the retest, we observed that 20 music experts and 16 non-experts were consistent in their judgments. Among each group, the correlations between consistent raters were positive. However, 67.38% of these correlations were significant (p < .05) for the music experts whereas only 42.10% were significant for the non-experts. In addition, no relationship occurred between the objective measurements (from 9.5 to 115.5 cents, M = 40.57, SD = 34.42) and the perceptual ratings, except for two music experts. This study highlights the consistency of a judge when rating operatic singing voices and the difference between music experts and non-experts concerning the inter-judges reliability. Despite the fact that the majority of the music experts used similar strategies to evaluate the vocal accuracy of operatic voices, their judgment was obviously not linked with the objective measurement of vocal accuracy. This finding supports the tolerance of music expert listeners regarding the singing voice accuracy of operatic singers. Furthermore, this study provides some directions about the perception of operatic singing voices, which are particularly complex. [less ▲]Detailed reference viewed: 16 (2 ULg)
How do paedomorphic newts cope with lake drying?
in Ecography (2003), 26(4), 405-410
Paedomorphosis, in which adult individuals retain larval traits, is widespread in newts and salamanders. Most evolutionary models predict the maintenance of this life-history trait in favourable aquatic ... [more ▼]
Paedomorphosis, in which adult individuals retain larval traits, is widespread in newts and salamanders. Most evolutionary models predict the maintenance of this life-history trait in favourable aquatic habitats surrounded by hostile terrestrial environments. Nevertheless, numerous ponds inhabited by paedomorphic individuals are unpredictable and temporary. In an experimental framework, I showed that paedomorphic newts were able to metamorphose and thus survive in the absence of water. However, the mere decrease of water level or the life space do not seem to induce metamorphosis in paedomorphs. On the contrary, drying up induces almost all individuals to move on land and after that to colonize other aquatic sites located nearby. Such terrestrial migrations allow survival in drying conditions without metamorphosis as long as the distances of terrestrial migration are short. These results are consistent with the presence of paedomorphs in drying ponds and are in favor of classic optimality models predicting metamorphosis in unfavorable environments. [less ▲]Detailed reference viewed: 115 (8 ULg)
How Do Performance Measures Perform
in Journal of Portfolio Management (2007), 33(4), 64-74
The article presents a discussion on how various performance measures actually perform when used in investment portfolio management. The author discusses the empirical quality of performance measures such ... [more ▼]
The article presents a discussion on how various performance measures actually perform when used in investment portfolio management. The author discusses the empirical quality of performance measures such as information ratio (IR), focusing on directional managed portfolios, the Treynor ratio, and an empirical methodology that allows many of the usual errors associated with ratios to be avoided. The author also discusses multi-index models, style-based mutual funds, and style-adjusted performance. [less ▲]Detailed reference viewed: 31 (7 ULg)
How do preschool teacher's requests influence children's behaviors ?
Crahay, Marcel ;
in Teaching & Teacher Education (1991), 7(3), 221-239Detailed reference viewed: 16 (2 ULg)
How do temperate bryophytes face the challenge of a changing environment? Lessons from the past and predictions for the future
Desamore, Aurélie ; Laenen, Benjamin ; et al
in Global Change Biology (2012), 18(9), 2915-2924
Bryophytes are a group of early land plants, whose specific ecophysiological and biological features, including poikilohydry, sensitivity to moderately high temperature and high dispersal ability, make ... [more ▼]
Bryophytes are a group of early land plants, whose specific ecophysiological and biological features, including poikilohydry, sensitivity to moderately high temperature and high dispersal ability, make them ideal candidates for investigating the impact of climate changes. Employing a combined approach of species distribution modelling (SDM) and molecular phylogeography in the temperate moss Homalothecium sericeum, we explore the significance of the Mediterranean refugia, contrasting the southern and northern refugia hypotheses, determine the extent to which recolonization of previously glaciated areas has been facilitated by the high dispersal ability of the species and make predictions on the extent to which it will be impacted by ongoing climate change. The Mediterranean areas exhibit the highest nucleotidic diversities and host a mixture of ancestral, endemic and more recently derived haplotypes. Extra-Mediterranean areas exhibit low genetic diversities and Euro-Siberian populations display a significant signal of expansion that is identified to be of Euro-Siberian origin, pointing to the northern refugia hypothesis. The SDMs predict a global net increase in range size owing to ongoing climate change, but substantial range reductions in southern areas. Presence of a significant phylogeographical signal at different spatial scales suggests, however, that dispersal limitations might constitute, as opposed to the traditional view of spore-producing plants as efficient dispersers, a constraint for migration. This casts doubts about the ability of the species to face the massive extinctions predicted in the southern areas, threatening their status of reservoir of genetic diversity. © 2012 Blackwell Publishing Ltd. [less ▲]Detailed reference viewed: 16 (2 ULg)
How do users formulate their queries? A morpho-syntactic analysis
Fairon, Nicolas ; Brouwir, Christine ; Durieux, Nancy et al
Conference (2008)Detailed reference viewed: 25 (1 ULg)
How do women entrepreneurs use the virtual network Facebook? The impact of gender
in International Journal of Entrepreneurship & Innovation (2011), 12(4), 257-269
This paper examines the views and attitudes of a sample of 228 female entrepreneurs towards the virtual social network Facebook. It identifies the main trends and uses statistical analysis to evaluate the ... [more ▼]
This paper examines the views and attitudes of a sample of 228 female entrepreneurs towards the virtual social network Facebook. It identifies the main trends and uses statistical analysis to evaluate the impact of their gendered sector of activity and of their self-perception on their view of this network as a response to gender-related difficulties and their use of it in relation to their activities and objectives. The study further investigates how Facebook may encourage and support women’s networks as well as benefit women-owned businesses. It highlights certain implications for public and private initiatives and underlines the potential of this and other virtual social networking sites for women’s entrepreneurship. [less ▲]Detailed reference viewed: 69 (5 ULg)
How does elicitor and antimicrobial fengycin interact with plasma membranes of sensitive cells ?
Nasir, Mehmet Nail ; ; Lins, Laurence et al
Conference (2012, April)
Fengycin is characterized by its strong antifungal and low hemolytic activities. It has also been recently demonstrated that it has plant elicitor properties and is also able to enhance the elicitors’ ... [more ▼]
Fengycin is characterized by its strong antifungal and low hemolytic activities. It has also been recently demonstrated that it has plant elicitor properties and is also able to enhance the elicitors’ activity of surfactin. The cell target of its biological activities is supposed to be plasma membrane. In spite of these interesting biological activities, fengycin has not been extensively investigated probably because of the difficulties related to its production. In a first time; we have characterized the interfacial properties of fengycin by tensiometry measurements and demonstrated that this surface activity was pH-dependent. In a second time; we have investigated the interactions of the lipopeptide with membrane lipids using model membranes such as Langmuir monolayers and multilammelar vesicles (MLVs). Our results indicate that the lipopeptide was able to penetrate into different lipid monolayers showing a preference for sterol-containing monolayers. In order to better understand the mechanism of the interactions of fengycin with membranes at the molecular level, MLVs with or without fengycin have been analyzed by spectroscopic techniques. We have shown that conformational changes of the lipopeptide occurred in the presence of lipids and they were more significant in the presence of sterol. Moreover, tyrosine residues of the lipopeptide seem to play an important role in these interactions. In conclusion, we have determined that the surface-active behavior as well as the conformation of fengycin depends on its environment. We have also showed that the lipopeptide does not interact with all class of lipids in the same way and presents a preference for sterols. The presence of key groups within peptide cycle has also been supposed for the biological activities of the lipopeptide. [less ▲]Detailed reference viewed: 106 (16 ULg)
How does engagement in reading predict digital reading proficiency among 15 year-olds?
Lafontaine, Dominique ; Monseur, Christian ; Baye, Ariane
Conference (2012, September)
In PISA 2009, 19 countries took part to an optional assessment of digital reading. In each country, a subsample of 15 year-olds was administered not only the paper and pencil PISA test, but also different ... [more ▼]
In PISA 2009, 19 countries took part to an optional assessment of digital reading. In each country, a subsample of 15 year-olds was administered not only the paper and pencil PISA test, but also different reading tasks online. The aim of our study is to investigate the relationships between engagement in reading, especially online reading practices, and digital reading proficiency of 15 year-olds in the 11 European countries which took part to this option (11 out of 19). [less ▲]Detailed reference viewed: 36 (1 ULg)