Last 7 days
Bookmark and Share    
Full Text
Peer Reviewed
See detailDo flower mixtures with high functional diversity enhance aphid predators in wildflower strips?
Hatt, Séverin ULg; Uyttenbroeck, Roel ULg; Chevalier Mendes Lopes, Thomas ULg et al

in European Journal of Entomology (2017), 114

Among semi-natural elements in agricultural landscapes, wildflower strips sown at field margins or within fields represent potential habitats for the natural enemies of insect pests. As insects are ... [more ▼]

Among semi-natural elements in agricultural landscapes, wildflower strips sown at field margins or within fields represent potential habitats for the natural enemies of insect pests. As insects are sensitive to a variety of flower traits, we hypothesised that mixtures with high functional diversity attract and support a higher abundance and species richness of aphid flower visiting predators compared to mixtures with low functional diversity. During a field experiment, repeated over two years (2014 and 2015) in Gembloux (Belgium), aphid predators (i.e., lacewings, ladybeetles and hoverflies) were pan-trapped in five sown flower mixtures (including a control mixture, with three replicates of each mixture) of low to high functional diversity based on seven traits (i.e., flower colour, ultra-violet reflectance and pattern, blooming start and duration, height and flower class, primarily based on corolla morphology). In both years, flower species in the sown mixtures (i.e., sown and spontaneous flowers) were listed, and the realised functional diversity of each plot was calculated. Over the two years, an increase in functional diversity did not result in an increase in the abundance and richness of aphid predators. Moreover, ladybeetles, representing the majority of trapped predators, were more abundant in mixtures with very low or intermediary functional diversity at sowing, especially in 2014. We hypothesise that certain flower species, which were abundant in certain mixtures (and not in those exhibiting the highest functional diversity), attracted predators and were sufficiently represented to support them. Our results present novel information that could be used to the development of flower mixtures that provide effective ecosystem services, such as pest control. [less ▲]

Detailed reference viewed: 36 (5 ULg)
Full Text
Peer Reviewed
See detailFacies discrimination with electrical resistivity tomography using a probabilistic methodology: Effect of sensitivity and regularization
Hermans, Thomas ULg; Irving, James

in Near Surface Geophysics (2017), 15

Electrical resistivity tomography (ERT) has become a standard geophysical method in the field of hydrogeology, as it has the potential to provide important information regarding the spatial distribution ... [more ▼]

Electrical resistivity tomography (ERT) has become a standard geophysical method in the field of hydrogeology, as it has the potential to provide important information regarding the spatial distribution of facies. However, inverted ERT images tend to be grossly smoothed versions of reality because of the regularization of the inverse problem. In this study, we use a probabilistic methodology based upon co-located measurements to assess the utility of ERT to identify hydrofacies in alluvial aquifers. With this methodology, ERT images are interpreted in terms of the probability of belonging to pre-defined hydrofacies. We first analyze through a synthetic study the ability of ERT to discriminate between different facies. As ERT data suffer from a loss of sensitivity with depth, we find that low sensitivity regions are more affected by misclassification. To counteract this effect, we adapt the probabilistic framework to include the spatially varying data sensitivity. We then apply our learning to a field case. For the latter, we consider two different regularization procedures. In contrast to the data sensitivity which affects the facies probability to a limited amount, the regularization can affect the probability maps more considerably because it has a strong influence on the spatial distribution of inverted resistivity. We find that a regularization strategy based on the most realistic prior information tends to offer the most reliable discrimination of facies. Our results confirm the ability of ERT surveys, when properly designed, to detect facies variations in alluvial aquifers. The method can be easily extended to other contexts. [less ▲]

Detailed reference viewed: 36 (15 ULg)
Full Text
Peer Reviewed
See detailEffect of steam explosion treatment on chemical composition and characteristic of organosolv fescue lignin
Maniet, Guillaume ULg; Schmetz, Quentin ULg; Jacquet, Nicolas ULg et al

in Industrial Crops and Products (2017), 99

Tall fescue, a grass currently grown as forage, presents a good potential as a feedstock in the developmentof biorefining. In this study, combination of steam explosion and an acetic/formic acid ... [more ▼]

Tall fescue, a grass currently grown as forage, presents a good potential as a feedstock in the developmentof biorefining. In this study, combination of steam explosion and an acetic/formic acid “organosolv”pretreatments are applied on raw fescue to optimize lignin extraction yields and obtain specific products.In a first step, fescue is pretreated by steam explosion under severity factors from 1.4 to 4.2. Thesetreatments allow hemicelluloses solubilization and open the lignocellulosic structure. Steam explodedsolid residues are then treated with an acetic acid (50%)/formic acid (30%)/water (20%) mixture. Extractedlignins are precipitated and characterized by size exclusion chromatography (SEC),31P NMR and HSQCNMR. Results show that acetic and formic acids extracted lignins present G, H and S units with ferulate andp-coumarate. Lignin typical linkages identified are of -O-4 and spirodienone substructures. Combinationof steam explosion and acetic and formic acid pretreatments increases extraction yields from 30% to100%. Moreover, an increase of the steam explosion treatment intensity induces chemical modificationsin lignin structure such -O-4 and spirodienone substructure degradations, increase of free COOH andphenolic OH bonds, decrease of aliphatic OH ferulate and p-coumarate bonds and changes in G/H/S unitsproportions. Steam explosion intensity affects also lignin molecular weights. [less ▲]

Detailed reference viewed: 28 (5 ULg)
Peer Reviewed
See detailHow does forest cover impact water flows and ecosystem services? Insights from real-life catchments in Wallonia (Belgium)
Brogna, Delphine; Vincke, Caroline; Brostaux, Yves ULg et al

in Ecological Indicators (2017), 72

While planet boundaries are being crossed and ecosystems degraded, the Ecosystem Service (ES) conceptrepresents a potential decision-making tool for improved natural resources management. The main aimof ... [more ▼]

While planet boundaries are being crossed and ecosystems degraded, the Ecosystem Service (ES) conceptrepresents a potential decision-making tool for improved natural resources management. The main aimof this paper is to assess the impact of forest cover on water related ES in Wallonia (Belgium) in termsof quantity and timing. We developed an approach based on easily accessible data, monitored in severalcountries and using straightforward statistical methods. This led us to study ES at “real-life” catchmentsscale: 22 catchments – from 30 to 250 km2– with mixed land covers were studied. We approached thewater supply and flood protection services through 5 indicators extracted from 10 hydrological years(2005–2014) discharge data series. These were computed annually and seasonally (vegetation periodfrom March to September and “non-vegetation” period the rest of the year). The water supply wasassessed through the specific volume Vs, the baseflow index BFI and the specific discharge exceeded95% of the time Q95s whereas the flood protection service was approached through the specific dis-charge exceeded 5% of the time Q05s and the flashiness index FI. Our study gives two main insights. First,statistical analyses show that forest cover negatively impact water supply when studying annual and“non-vegetation” period flows in general (Vs) but positively when studying low flows (Q95s). Regardingflood protection a slightly negative impact of forest cover on high flows (Q05s) was highlighted in the“non-vegetation” period. Results also show a negative impact of forests annually and in the vegetationperiod on the flashy behaviour of the catchment thus a positive impact on the flood protection ES. The“year” effect is overall highly significant testifying the importance of climatic factors. Rainfall is oftensignificant and can be considered as a main driver of these ES. Secondly, analyzing the quality of themodels produced and the results overall we assume that other variables characterizing the catchmentssuch as topography or soil types do play a significant role in the delivery of these ES. This questions theuse of land cover proxies in assessing and mapping of hydrological ES at a complex landscape scale. Wethus recommend further research to keep improving land cover proxies if they are used. [less ▲]

Detailed reference viewed: 53 (13 ULg)
Full Text
Peer Reviewed
See detailL'énonciation vidéoludique : analyse du jeu Portal
Barnabé, Fanny ULg

in Dondero, Maria Giulia; Beyaert-Geslin, Anne; Moutat, Audrey (Eds.) Les plis du visuel. Réflexivité et énonciation dans l'image (2017)

Si la sémiotique visuelle a aujourd’hui largement exploré bon nombre de domaines, le jeu vidéo demeure un champ relativement peu étudié via cette approche. Il constitue, en ce sens, un objet à la fois ... [more ▼]

Si la sémiotique visuelle a aujourd’hui largement exploré bon nombre de domaines, le jeu vidéo demeure un champ relativement peu étudié via cette approche. Il constitue, en ce sens, un objet à la fois problématique (car l’application des concepts développés pour les autres types d’images risque parfois de mener à des impasses) et potentiellement fécond (car il permet de tester ces mêmes concepts sur un objet qui leur résiste et éventuellement d’ouvrir de nouvelles perspectives). La question de l’énonciation vidéoludique, par contre, suscite déjà l’intérêt : différents chercheurs tels que Genvo (2008), Mabillot (2001), Amato (2005), Mpondo-Dicka (2005) ou Nélide-Mouniapin (2005) ont, en effet, déjà soulevé cette problématique. Néanmoins, celle-ci est rarement abordée sous l’angle de la sémiotique visuelle. La nouveauté du sujet implique donc que l’analyse que nous proposerons ici, loin d’être un état des lieux complet et abouti, aura plutôt pour objectif d’ouvrir le champ de la réflexion et de proposer des pistes d’interrogation pour aborder ce système sémiotique complexe qu’est le jeu vidéo. Malgré tout, dans le but d’asseoir nos observations sur des bases concrètes, nous nous intéresserons à une œuvre vidéoludique particulière : le jeu de réflexion Portal, développé en 2007 par Valve Corporation. [less ▲]

Detailed reference viewed: 18 (2 ULg)
Full Text
Peer Reviewed
See detailEFHC1 variants in juvenile myoclonic epilepsy: reanalysis according to NHGRI and ACMG guidelines for assigning disease causality
Bailey, JN; Patterson, C; de Nijs, L et al

in Genetics in Medicine (2017)

Detailed reference viewed: 17 (2 ULg)
Full Text
Peer Reviewed
See detailDon't judge a fish by its fins: species delineation of Congolese Labeo (Cyprinidae)
Van Steenberge, Maarten; Gajdzik, Laura ULg; Chilala, Alex et al

in Zoologica Scripta (2016)

Conspicuous characters are often useful in species identification. Yet, identification and delineation are two different processes, and such characters do not necessarily provide the best basis on which ... [more ▼]

Conspicuous characters are often useful in species identification. Yet, identification and delineation are two different processes, and such characters do not necessarily provide the best basis on which species can be delineated. This is illustrated by the case of the Labeo with papillary lips from the Congo basin. Traditionally, species delineation in this group was based on a conspicuous trait: the shape of the dorsal fin, which shows a profound degree of differentiation. Morphometric analyses were performed on 185 specimens both with and without measurements taken on this fin. The groups obtained using these two approaches were compared with those obtained through DNA barcoding. For this, 24 sequences of the standard barcoding COI gene were obtained. Species delineations based on morphological and molecular results were in agreement when the shape of the dorsal fin was ignored. This suggested that of the five nominal species known from the Congo basin, L. altivelis, L. rosae, L. lineatus, L. weeksii and L. maleboensis, only the former three remain valid. Consequently, L. weeksii was synonymised with L. altivelis and L. maleboensis with L. lineatus. The sole Congo basin endemic is L. lineatus as L. altivelis and L. rosae also occur in more southern basins. The use of the shape of the dorsal fin in morphological studies has previously led to overestimates of species diversity in this group. This is due to the fact that L. altivelis shows a remarkable amount of geographical variation for this trait. The large amount of intra- and interspecific variation in this character was caused by differential allometric growth in different parts of the dorsal fin. [less ▲]

Detailed reference viewed: 15 (2 ULg)
Full Text
Peer Reviewed
See detailComprehension of an organosolv process for lignin extraction on Festuca arundinacea and monitoring of the cellulose degradation
Schmetz, Quentin ULg; Maniet, Guillaume ULg; Jacquet, Nicolas ULg et al

in Industrial Crops and Products (2016), 94

It is commonly accepted that the current society needs to partially substitute fossil resources by renewable ones. Among many solutions, one approach consists in the development of biorefinery involving ... [more ▼]

It is commonly accepted that the current society needs to partially substitute fossil resources by renewable ones. Among many solutions, one approach consists in the development of biorefinery involving lignocellulosic biomass to produce bio-based materials and fuels. This study focuses on the comprehension of an organosolv treatment designed to break the complex lignocellulosic structure for high purity lignin extraction from tall fescue (Festuca arundinacea Schreb.). This grass benefits from an increasing interest in Western Europe and has been suggested as feedstock for biorefinery. However, its use as material for high purity lignin production has not been determined yet. Ethanol/water, 92/8% [v/v] with H2SO4 0.32 M was investigated at pilot scale under conventional heating (5 °C min−1 during 30 min and stabilized at 148 °C for 5 min). Precipitated lignin were analyzed as well as the composition of side-stream products (recovered cellulosic pulp and the aqueous hydrolysate). Lignin has been recovered at a purity level of 90% with a yield of 60%. The main contaminants were nitrogen containing compounds and degraded hemicelluloses. 2D-HSQC NMR (Two Dimension-Heteronuclear Single Quantum Correlation Nuclear Magnetic Resonance) revealed a co-extraction of ferulates and coumarates function as well as arabinoxylan. Cellulose was recovered at 53% purity with 60% yield. The conditions appear to be too harsh for tall fescue and led to significant amount of cellulose degradation. A process using a lower alcohol concentration will be developed to provide better yields of both cellulose and lignin. [less ▲]

Detailed reference viewed: 68 (16 ULg)
Full Text
Peer Reviewed
See detailContinuous Production of Itraconazole-based Solid Dispersions by Hot Melt Extrusion: Preformulation, Optimization and Design Space Determination.
Thiry, Justine ULg; Lebrun, Pierre; Vinassa, Chloé et al

in International Journal of Pharmaceutics (2016), 515(1-2), 114-124

Detailed reference viewed: 47 (9 ULg)
Full Text
Peer Reviewed
See detailInterpellation du genre et sujets mélancoliques. Butler lectrice d’Althusser
Borotto, Jessica ULg

in Cahiers du GRM (2016), 8

Cet article propose d’explorer la manière dont Judith Butler remobilise la thèse althussérienne de l’interpellation dans La Vie psychique du pouvoir . Nous essaierons de saisir les éléments qui nous ... [more ▼]

Cet article propose d’explorer la manière dont Judith Butler remobilise la thèse althussérienne de l’interpellation dans La Vie psychique du pouvoir . Nous essaierons de saisir les éléments qui nous paraissent enrichir la problématique althussérienne, suggérant que la compréhension de la dimension psychique du pouvoir qui ressort de sa lecture permet de complexifier la relation du sujet au pouvoir. Afin de tisser des liens précis entre l’interpellation chez Althusser et la subjectivation chez Butler, nous examinerons d’abord le rôle que Nietzsche et Foucault recouvrent dans la formulation de la théorie de la subjectivation chez Butler. Ensuite, il s’agit de comprendre en quoi la matérialité et l’ambiguïté des mécanismes de subjectivation, qui déjà caractérisent l’interpellation althussérienne, deviennent chez Butler les sources d’une relation critique aux conditions d’émergence du sujet. Enfin nous préciserons comment elle mobilise de telles sources pour élaborer cette figure de la psychanalyse qu’est la mélancolie et pour décrire sa transformation en deuil. [less ▲]

Detailed reference viewed: 18 (1 ULg)
Full Text
Peer Reviewed
See detailIs Competence a Holy Grail for Teaching? Reflections on Nursing Education
Dancot, Jacinthe ULg

in Nursing & Care Open Access Journal (2016), 1(4), 00021

The competence-based approach is largely widespread in the nursing schools and is viewed as a golden standard for professional teaching. But the practical use of the concept is varying among institutions ... [more ▼]

The competence-based approach is largely widespread in the nursing schools and is viewed as a golden standard for professional teaching. But the practical use of the concept is varying among institutions and even teachers. The goal of this narrative review is to clarify the conception of competence and its use in the fields of education and nursing. Regarding education, Gonczi, Tardif, Jonnaert and Beckers are the key authors referred to. A first apparent consensus over the holistic nature of the competence quickly gives place to the observation of important nuances in conceptions. Similarly, in the field of nursing, Benner is first discussed, and recent literature reviews and concept analyses are taken into account: similar nuances are detected, as well as difficulties in the practical implementation of the concept. Considering the lack of consensus and the paradigmaticalincoherences detected among the sources consulted for this review, we question the use of competence as single point of view for teaching and assessing, and we propose other avenues to be explored in order to recognize emergent professionality. [less ▲]

Detailed reference viewed: 312 (2 ULg)
Full Text
Peer Reviewed
See detailLearning from Incidents and Incident Reporting: Safety Governance at a Belgian Nuclear Research Center
Rossignol, Nicolas ULg; Van Oudheusden, Michiel ULg

in Science, Technology & Human Values (2016), Online First

This article examines how incidents are governed in a Belgian Nuclear Research Center by way of an incident reporting system named REX. Drawing on a documentary analysis of incident reports, interviews ... [more ▼]

This article examines how incidents are governed in a Belgian Nuclear Research Center by way of an incident reporting system named REX. Drawing on a documentary analysis of incident reports, interviews and focus groups with personnel, it illustrates how REX enacts a safety governmentality centered on identifying incident causes and culprits. As this governmentality mode obscures the epistemic and political character of incidents, it closes down important opportunities for collective learning about safety and safety governance. It is argued that joint reflection about incidents and resistances towards incident reporting serve as fruitful starting points for a more reflexive safety governance that makes explicit how decisions are made in high-risk contexts. Social scientists can enhance governance of this kind by pointing to different perceptions and evaluations of incidents and by insisting that contending interpretations are confronted and accounted for. [less ▲]

Detailed reference viewed: 17 (3 ULg)
Full Text
Peer Reviewed
See detailScreening transplant donors for HTLV-1 and -2
Gallo, Robert; Willems, Luc ULg; Hasegawa, 4 Hideki et al

in Blood (2016), 128(26),

Detailed reference viewed: 10 (1 ULg)
Full Text
Peer Reviewed
See detailNeuromuscular blockade as part of an anaesthetic protocol for cataract surgery in an alpaca
Tutunaru, Alexandru-Cosmin ULg; Storms, Goedele ULg; Monclin, Sébastien ULg et al

in Journal of Camelid Science (2016), 9

A six-month-old alpaca was presented to the veterinary teaching hospital of the University of Liège (Belgium) with a bilateral cataract. A decision was made to perform bilateral cataract surgery after an ... [more ▼]

A six-month-old alpaca was presented to the veterinary teaching hospital of the University of Liège (Belgium) with a bilateral cataract. A decision was made to perform bilateral cataract surgery after an ocular ultrasound and electroretinogram were performed to assess the posterior segment and retinal function, respectively. As a premedication, the alpaca received xylazine, butorphanol and midazolam intramuscularly. Anaesthesia was induced subsequently with ketamine and midazolam intravenously and maintained with isoflurane on oxygen/air mixture. The alpaca was mechanically ventilated during surgery. Neuromuscular blockade was induced and maintained with cis-atracurium intravenously. The dose of cis-atracurium was permanently adapted using a peripheral nerve stimulator. This case report brings new knowledge regarding the use and dosage of cis-atracurium in alpacas. [less ▲]

Detailed reference viewed: 16 (4 ULg)
Full Text
Peer Reviewed
See detailEditorial
Borotto, Jessica ULg; Petteni, Oriane ULg; Wustefeld, Sophie ULg et al

in Cahiers du GRM (2016), 10

Detailed reference viewed: 16 (6 ULg)
Full Text
Peer Reviewed
See detailEffect of the Extraction Technique, Heating Time and Cryogenic Grinding (N2 at -196°C) on the Composition of Cumin Seeds Volatile Oil
Mékaoui, R; Benkaci-Ali, Farid; Scholl, Georges ULg et al

in Journal of Essential Oil-Bearing Plants [=JEOBP] (2016), 19(8), 1903-1919

Two techniques of extraction of essential oils (Steam distillation assisted by microwave (SDAM) and hydrodistillation assisted by microwave (HDAM)) are respectively advanced steam distillation (SD) and ... [more ▼]

Two techniques of extraction of essential oils (Steam distillation assisted by microwave (SDAM) and hydrodistillation assisted by microwave (HDAM)) are respectively advanced steam distillation (SD) and hydrodistillation techniques (HD), in which a microwave oven is used in the extraction process. They are considered as accelerated techniques extraction performed at atmospheric pressure. The cryogrinding (CG) showed a difference on the yields and aromatic profile comparing to the sample grinding. Isolation and concentration of volatile compounds are performed by a single stage for the extraction of volatile oil from Algerian (Sahara) Cuminum cyminum seeds (CCS). The chemical composition of the essential oil of this plant as a function of extraction time was also studied. The major components and family classes showed a significant variation with the extraction time. Gas chromatography (GC), GCxGC-mass spectrometry (GCxGC-MS)] were utilised for qualitative and quantitative analysis of essential oils extracted by these two methods. The major compounds are cumin aldehyde (HDAM-CG: 20.50-53.35 %, SDAM-CG: 21.68 66.6 %), p-cymene (HDAM-CG: 14.1-37.54 %, SDAM-CG: 6.06-20.18 %), β-pinene (HDAM-CG: 4.53-14.74 %, SDAM-CG: 4.3-32.65 %) and γ-terpinene (HDAM-CG: 1.26-14.70 %, SDAM-CG: 5.13-18.23 %). [less ▲]

Detailed reference viewed: 13 (1 ULg)
Full Text
Peer Reviewed
See detailSU(3) flavor symmetry breaking in large $N_c$ excited baryons
Stancu, Floarea ULg

in Physical Review. D : Particles and Fields (2016), 94

The $1/N_c$ expansion method for studying the mass spectrum of excited baryons is shortly reviewed together with applications to mixed symmetric states. The $[{\bf 70, \ell^+}]$ multiplet, belonging to ... [more ▼]

The $1/N_c$ expansion method for studying the mass spectrum of excited baryons is shortly reviewed together with applications to mixed symmetric states. The $[{\bf 70, \ell^+}]$ multiplet, belonging to the $N$ = 2 band, is reanalyzed, with emphasis on hyperons and the SU(3) symmetry breaking operators entering the mass formula to first order. An important result is that the hierarchy of masses as a function of strangeness is correctly reproduced for all multiplets. Predictions for unknown excited hyperons to SU(6) $\times$ O(3) multiplets are made. [less ▲]

Detailed reference viewed: 10 (2 ULg)
Full Text
See detailAgricultural economics and development with implications to the Central Highlands
Lebailly, Philippe ULg

Scientific conference (2016, December 23)

Detailed reference viewed: 14 (2 ULg)