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See detailEffects of low dose endosulfan exposure on brain neurotransmitter levels in the African clawed frog Xenopus laevis
Preud'Homme, Valérie; Milla, Sylvain; Gillardin, Virginie et al

in Chemosphere (2015), 120(2), 357-364

Understanding the impact of pesticides in amphibians is of growing concern to assess the causes of their decline. Among pesticides, endosulfan belongs to one of the potential sources of danger because of ... [more ▼]

Understanding the impact of pesticides in amphibians is of growing concern to assess the causes of their decline. Among pesticides, endosulfan belongs to one of the potential sources of danger because of its wide use and known effects, particularly neurotoxic, on a variety of organisms. However, the effect of endosulfan was not yet evaluated on amphibians at levels encompassing simultaneously brain neurotransmitters and behavioural endpoints. In this context, tadpoles of the African clawed frog Xenopus laevis were submitted to four treatments during 27 d: one control, one ethanol control, and two low environmental concentrations of endosulfan (0.1 and 1 μg L−1). Endosulfan induced a significant increase of brain serotonin level at both concentrations and a significant increase of brain dopamine and GABA levels at the lower exposure but acetylcholinesterase activity was not modified by the treatment. The gene coding for the GABA transporter 1 was up-regulated in endosulfan contaminated tadpoles while the expression of other genes coding for the neurotransmitter receptors or for the enzymes involved in their metabolic pathways was not significantly modified by endosulfan exposure. Endosulfan also affected foraging, and locomotion in links with the results of the physiological assays, but no effects were seen on growth. These results show that low environmental concentrations of endosulfan can induce adverse responses in X. laevis tadpoles. At a broader perspective, this suggests that more research using and linking multiple markers should be used to understand the complex mode of action of pollutants. [less ▲]

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See detailExperimental modal analysis of nonlinear structures using broadband data
Noël, Jean-Philippe ULg; Renson, Ludovic ULg; Grappasonni, Chiara ULg et al

in Proceedings of the International Modal Analysis Conference (IMAC) XXXIII (2015, February)

The objective of the present paper is to develop a rigorous identification methodology of nonlinear normal modes (NNMs) of engineering structures. This is achieved by processing experimental measurements ... [more ▼]

The objective of the present paper is to develop a rigorous identification methodology of nonlinear normal modes (NNMs) of engineering structures. This is achieved by processing experimental measurements collected under broadband forcing. The use of such a type of forcing signal allows to excite multiple NNMs simultaneously and, in turn, to save testing time. A two-step methodology integrating nonlinear system identification and numerical continuation of periodic solutions is proposed for the extraction of the individual NNMs from broadband input and output data. It is demonstrated using a numerical cantilever beam possessing a cubic nonlinearity at its free end. The proposed methodology can be viewed as a nonlinear generalization of the phase separation techniques routinely utilized for experimental modal analysis of linear structures. The paper ends with a comparison between this new nonlinear phase separation technique and a previously-developed nonlinear phase resonance method. [less ▲]

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See detailExperimental nonlinear identification of an aircraft with bolted connections
De Filippis, Giovanni; Noël, Jean-Philippe ULg; Kerschen, Gaëtan ULg et al

in Proceedings of the International Modal Analysis Conference (IMAC) XXXIII (2015, February)

Aircraft structures are known to be prone to nonlinear phenomena, especially as they constantly become lighter and hence more flexible. One specific challenge that is regularly encountered is the modeling ... [more ▼]

Aircraft structures are known to be prone to nonlinear phenomena, especially as they constantly become lighter and hence more flexible. One specific challenge that is regularly encountered is the modeling of the mounting interfaces between aircraft subcomponents. Indeed, for large amplitudes of vibration, such interfaces may loosen and, in turn, trigger complex mechanisms such as friction and clearances. In this context, the present work intends to investigate the nonlinear dynamics of the Morane–Saulnier Paris aircraft, accessible at ONERA. This aircraft possesses multiple bolted connections between two external fuel tanks and wing tips. The objective of the paper is specifically to carry out an adequate identification of the numerous nonlinearities affecting the dynamics of this full-scale structure. Nonlinearity detection and the subsequent subspace-based parameter estimation have been performed on experimental data, collected during an on-ground test campaign. Nonlinearity detection is first achieved by the comparison of frequency response functions estimated at low excitation level, with those obtained at high amplitude level, yielding insight towards accurately characterizing the behavior of the bolted connections. Then, a nonlinear subspace identification method is applied to measured data to estimate the linear and nonlinear parameters of the structure and novel strategies and tools that overcome specific arisen problems are developed. [less ▲]

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See detailOn modular decompositions of system signatures
Marichal, Jean-Luc; Mathonet, Pierre ULg

in Journal of Multivariate Analysis (2015), 134

Considering a semicoherent system made up of $n$ components having i.i.d. continuous lifetimes, Samaniego defined its structural signature as the $n$-tuple whose $k$-th coordinate is the probability that ... [more ▼]

Considering a semicoherent system made up of $n$ components having i.i.d. continuous lifetimes, Samaniego defined its structural signature as the $n$-tuple whose $k$-th coordinate is the probability that the $k$-th component failure causes the system to fail. This $n$-tuple, which depends only on the structure of the system and not on the distribution of the component lifetimes, is a very useful tool in the theoretical analysis of coherent systems. It was shown in two independent recent papers how the structural signature of a system partitioned into two disjoint modules can be computed from the signatures of these modules. In this work we consider the general case of a system partitioned into an arbitrary number of disjoint modules organized in an arbitrary way and we provide a general formula for the signature of the system in terms of the signatures of the modules. The concept of signature was recently extended to the general case of semicoherent systems whose components may have dependent lifetimes. The same definition for the $n$-tuple gives rise to the probability signature, which may depend on both the structure of the system and the probability distribution of the component lifetimes. In this general setting, we show how under a natural condition on the distribution of the lifetimes, the probability signature of the system can be expressed in terms of the probability signatures of the modules. We finally discuss a few situations where this condition holds in the non-i.i.d. and nonexchangeable cases and provide some applications of the main results. [less ▲]

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See detailExperimental demonstration of a 3D-printed nonlinear tuned vibration absorber
Grappasonni, Chiara ULg; Habib, Giuseppe ULg; Detroux, Thibaut ULg et al

in Proceedings of the International Modal Analysis Conference (IMAC) XXXIII (2015, February)

Engineering structures are designed to be lighter and more flexible, hence reducing the extent of application of linear dynamic models. Concurrently, vibration mitigation is required for enhancing the ... [more ▼]

Engineering structures are designed to be lighter and more flexible, hence reducing the extent of application of linear dynamic models. Concurrently, vibration mitigation is required for enhancing the performance, comfort or safety in real-life applications. Passive linear vibration absorbers are purpose-built, often designed using Den Hartog's equal-peak strategy. However, nonlinear systems are known to exhibit frequency-energy-dependent oscillations which linear absorbers cannot effectively damp out. In this context, the paper introduces a new nonlinear tuned vibration absorber (NLTVA) whose nonlinear functional form is tailored according to the frequency-energy dependence of the nonlinear primary structure. The NLTVA design aims at ensuring equal peaks in the nonlinear receptance function for an as large as possible range of forcing amplitudes, hence generalizing Den Hartog's method to nonlinear systems. Our focus in this study is on experimental demonstration of the NLTVA performance using a primary structure consisting of a cantilever beam with a geometrically nonlinear component at its free end. The absorber is implemented using a doubly-clamped beam fabricated thanks to 3D printing. The NLTVA performance is also compared with that of the classical linear tuned vibration absorber. [less ▲]

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See detailGeräusch, Gerücht, Gerede. Formen und Funktionen der Fama in Erzähltexten Theodor Storms und Arthur Schnitzlers
Leyh, Valérie ULg

Doctoral thesis (2015)

Dans sa représentation allégorique de Fama, le poète latin Ovide évoque trois phénomènes précis : son aspect acoustique (le bruit), sa forme discursive (les racontars) et son lien au récit (la rumeur ... [more ▼]

Dans sa représentation allégorique de Fama, le poète latin Ovide évoque trois phénomènes précis : son aspect acoustique (le bruit), sa forme discursive (les racontars) et son lien au récit (la rumeur). Alors que ces phénomènes ont très souvent fait l'objet d’études sociologiques et anthropologiques, il s’agit ici de les étudier en tant qu’objets d’un processus d’esthétisation. La thèse vise ainsi à décrire une « poétique de Fama » par l’analyse d’un choix de textes narratifs des auteurs germanophones Theodor Storm (1817 – 1888) et Arthur Schnitzler (1862 – 1931). En effet, les recherches récentes sur l’anticipation de la psychologie et sur les questions de perception chez Storm soulignent l’importance de stratégies narratives au caractère indirect, voilé et mettant à mal la plausibilité ; elles révèlent la nécessité d’étudier la rumeur comme élément thématique mais aussi structurel et formel. Les nombreux aspects de Fama intimement liés aux processus narratifs (polyphonie, psychologisation, contournement de la censure) permettent ensuite de confronter les textes de Storm à ceux de Schnitzler et d'y préciser les interactions subtiles entre bruit, racontars et rumeur. Dans ce traitement littéraire de Fama, il s’avère en outre primordial de mettre en lumière ses multiples fonctions selon les différents niveaux textuels (personnages, narrateur, auteur) et d’accorder une place au lecteur qui, dans une approche interactionnelle du récit, prend souvent part à la communication rumorale. Ces distinctions permettent de mettre en exergue la dimension poétologique de Fama dans ses différentes formes : si celle-ci participe à la création d’effets paradoxaux et de structures équivoques au sein des textes, c’est parce que la rumeur, en tant que forme de narration à caractère ambivalent et protéiforme, est fortement autoréflexive. L’instabilité et la contingence, l’indétermination de seuils et de frontières sont autant de traits qui caractérisent non seulement la rumeur et les racontars mais aussi les textes d’une époque marquée par de grandes mutations et par la mise en doute de valeurs et données acquises jusque-là. [less ▲]

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See detailUsing shear strain localisation to model the fracturing around gallery in unsaturated Callovo-Oxfordian claystone
Pardoen, Benoît ULg; Levasseur, Séverine ULg; Collin, Frédéric ULg

in Chau, Kam Tim; Zhao, Jidong (Eds.) Bifurcation and Degradation of Geomaterials in the New Millennium (2015, January 28)

Galleries drilling leads to damage propagation, fracturing and properties modifications in the surrounding medium. The prediction of the damaged zone behaviour is an important matter and needs to be ... [more ▼]

Galleries drilling leads to damage propagation, fracturing and properties modifications in the surrounding medium. The prediction of the damaged zone behaviour is an important matter and needs to be properly assessed. To do so the fractures can be modelled using shear strain localisation. The coupled local second gradient model is used under unsaturated conditions to correctly model the strain localisation behaviour. The permeability evolution and the rock desaturation due to air ventilation in galleries are considered. Finally, a hydro-mechanical modelling of a gallery excavation in Callovo-Oxfordian claystone is performed leading to a fairly good representation of the damaged zone. [less ▲]

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See detailSimplified analytical methods for the crashworthiness and the seismic design of lock gates
Buldgen, Loïc ULg

Doctoral thesis (2015)

The PhD dissertation aims to provide simplified tools based on analytical formulations in order to ease the pre-design of lock gates. The first part of the thesis is devoted to ship collisions. The ... [more ▼]

The PhD dissertation aims to provide simplified tools based on analytical formulations in order to ease the pre-design of lock gates. The first part of the thesis is devoted to ship collisions. The resistance of the impacted gate is evaluated by combining global and local deforming modes. In the second part of the dissertation, an analytical solution is proposed to estimate the total hydrodynamic pressure acting on a lock gate during a seism, with due consideration for the fluid-structure coupling. Numerical validations are proposed for both ship collisions and earthquakes. [less ▲]

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See detailEffect of stress path on the miniaturizatio size effect for nickel polycrystals
Keller, Clement; Hug, Eric; Duchene, Laurent ULg et al

Conference (2015, January 04)

The mechanical behavior of mettalic materials deeply depends on the size of samples. For specimen dimensions de creasing from a few millimeters to a few micrometers, the general observed trend is a ... [more ▼]

The mechanical behavior of mettalic materials deeply depends on the size of samples. For specimen dimensions de creasing from a few millimeters to a few micrometers, the general observed trend is a softening of the mechanical behavior in tension which affects the stress level and the strain hardening. This effect is triggered by the derease of the number of grains across the thickness ( also called thickness"t" over grain size "d" ratio). The objective of this work is to provide new experimental results in order to analyse the miniaturization size effects for various stress paths without strain gradients across the thickness of the samples. To this aim, experimental tensil tests, large tensile tests and shear tests have been performed on Ni sheets ( 0.5mm) with various grain sizes ensuring different t/d ratios. Results show that the miniaturization softening is affected by triaxiality, the larger is this parameter, the lower is the mechanicval softening. These features seem to be linked to surface effects which are larger for low triaxiality stress paths. Attempts of numerical simulations using strain gradient crystal plasticity model are also performed to confirm the role played by surface effects. [less ▲]

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See detailThe impact of transport policies on railroad intermodal freight competitiveness – The case of Belgium
Santos, Bruno F.; Limbourg, Sabine ULg; Carreira, Joana Silva

in Transportation Research. Part D : Transport and Environment (2015), 34

This paper discusses the impact of three freight transport policies aiming to promote railroad intermodal transport in Europe, and examines the case of Belgium as a testing ground. These policies consist ... [more ▼]

This paper discusses the impact of three freight transport policies aiming to promote railroad intermodal transport in Europe, and examines the case of Belgium as a testing ground. These policies consist in subsidizing intermodal transport operations (such as in Belgium, to stimulate rail transport), internalizing external costs (as recommended by the European Union in order to foster cleaner modes), and adopting a system perspective when optimizing the location of inland intermodal terminals. The study proposes an innovative mixed integer intermodal freight location-allocation model based on hub-location theory and deals with non-linear transport costs in order to replicate economies of distance. Our analysis suggests that subsidizing has a significant impact on the volumes transported by intermodal transport, and, to a lesser extent, that optimizing terminal location increases the competitiveness of intermodal transport. On the other hand, according to our assumptions, internalizing external costs can negatively impact the promotion of intermodality. This finding indicates that innovative last-mile transports are needed in order to reduce the external impacts of drayage operations. [less ▲]

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See detailBiochemical characterisation of the seed oils of four safflower (Carthamus tinctorius) varieties grown in north-eastern of Morocco
Ben Moumen, Abdessamad; Mansouri, Farid; Richard, Gaetan ULg et al

in International Journal of Food Science & Technology (2015)

The quality of the oil of four safflower varieties, originating from Spain (Rancho), India (Sharda) and Morocco (Cartamar and Cartafri), which were cultivated at the experimental station in Oujda (a semi ... [more ▼]

The quality of the oil of four safflower varieties, originating from Spain (Rancho), India (Sharda) and Morocco (Cartamar and Cartafri), which were cultivated at the experimental station in Oujda (a semi-arid region of eastern Morocco) was evaluated through analysis of their phenolic and carotenoid contents. The composition of the phenolic compounds of safflower oil has not yet been documented. Therefore, in this preliminary study, Thirty different phenolic compounds were identified, and significant differences between the oil varieties were observed (P < 0.05). In the seed oil from the Rancho and Sharda safflower varieties, the main phenolic compound was trans-chalcone, representing 13.45% and 11.8%, respectively, of the total phenolics, whereas in Cartamar and Cartafri oils, naringin accounted for 26.82% and 16.5%, respectively, of the total phenolics. The total carotenoid contents ranged from 1.13 mg/kg (Rancho) to 1.34 mg/kg (Cartamar and Cartafri).We observed that b-cryptoxanthin (0.31–0.37 mg/kg) and b-carotene (0.3–0.35 mg/kg) were the predominant carotenoids in all of the safflower oils that were studied. [less ▲]

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See detailOn the necessity and biological significance of threshold-free regulon prediction outputs
Rigali, Sébastien ULg; Nivelle, Renaud; Tocquin, Pierre ULg

in Molecular Biosystems (2015)

The in silico prediction of cis-acting elements in a genome is an efficient way to quickly obtain an overview of the biological processes controlled by a trans-acting factor, and connections between ... [more ▼]

The in silico prediction of cis-acting elements in a genome is an efficient way to quickly obtain an overview of the biological processes controlled by a trans-acting factor, and connections between regulatory networks. Several regulon prediction web tools are available, designed to identify DNA motifs predicted to be bound by transcription factors using position weight matrix-based algorithms. In this paper we expose and discuss the conflicting objectives of software creators (bioinformaticians) and software users (biologists), who aim for reliable and exhaustive prediction outputs, respectively. Software makers, concerned with providing tools that minimise the number of false positive hits, often impose a stringent threshold score for a sequence to be included in the list of the putative cis-acting sites. This rigidity eventually results in the identification of strongly reliable but largely straightforward sites, i.e. those associated with genes already anticipated to be targeted by the studied transcription factor. Importantly, this biased identification of strongly bound sequences contrasts with the biological reality where, in many circumstances, a weak DNA-protein interaction is required for the appropriate gene's expression. We show here a series of transcriptionally controlled systems involving weakly bound cis-acting elements that could never have been discovered because of the policy of preventing software users from modifying the screening parameters. Proposing only trustworthy prediction outputs thus prevents biologists from fully utilising their knowledge background and deciding to analyse statistically irrelevant hits that could nonetheless be potentially involved in subtle, unexpected, though essential cis-trans relationships. [less ▲]

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See detailVers une généralisation des quartiers durables ? Présentation du référentiel d’aide à la conception et à l’évaluation développé en Wallonie et analyse prospective de douze quartiers.
Marique, Anne-Françoise ULg; Delbar, Caroline; Loiseau, Véronique ULg et al

in Urbia (2015)

Un référentiel a été développé en Wallonie, à la demande du Ministre de l’Environnement, de l’Aménagement du Territoire et de la Mobilité, pour opérationnaliser le concept de « quartier durable » en ... [more ▼]

Un référentiel a été développé en Wallonie, à la demande du Ministre de l’Environnement, de l’Aménagement du Territoire et de la Mobilité, pour opérationnaliser le concept de « quartier durable » en objectivant les critères minimum à respecter pour inscrire un quartier dans une vision transversale de développement durable. Ce référentiel constitue un cadre général qui régira les projets de quartiers durables menés en Wallonie (Belgique). Les 5 thématiques et les 25 critères qui constituent ce référentiel sont présentés. La grille de critères est ensuite appliquée à douze quartiers de façon à identifier les invariants communs aux processus de conception de ces quartiers et les freins à l’intégration des principes transversaux du développement durable dans les opérations de ce type. Si les critères relatifs aux performances énergétiques des bâtiments ont percolé dans un grand nombre de cas, la mixité des logements et leur accessibilité, la mixité sociale et la participation restent peu abordés. Le référentiel est disponible depuis début 2014 pour tous les acteurs de l’architecture et de l’urbanisme. [less ▲]

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See detailFair Trade and Social Enterprise
Huybrechts, Benjamin ULg

in Raynolds, Laura; Bennett, Elizabeth (Eds.) The Handbook of Research on Fair Trade (2015)

This chapter suggests that the notion of ‘social enterprise’ is useful to capture the DNA of organizations focused on fair trade and to locate them within a broader organizational taxonomy. Without ... [more ▼]

This chapter suggests that the notion of ‘social enterprise’ is useful to capture the DNA of organizations focused on fair trade and to locate them within a broader organizational taxonomy. Without seeking to impose a new term that may not resonate for certain actors or regions, this chapter aims to bring two contributions to fair trade research and practice. First, it is suggested that the social enterprise approach is particularly useful as an analytical tool enabling researchers and other stakeholders to capture the evolution and diversification of organizational models in fair trade. Second, the use of a broader organizational approach that is not specific to the sole fair trade sector allows for connections with similar organizations in other sectors and brings a shift from considering mainly what the organizations do (fair trade in this case) towards also addressing what they are (innovative social enterprise models combining market dynamics with social purpose). This chapter is structured as follows. First, the concept of social enterprise is introduced and discussed. Then, the evolution of the organizational landscape of fair trade (in the North) is summarized. Finally, fair trade organizations are examined in the light of the social enterprise concept, with illustrations from a study in four European countries (Huybrechts 2010a; 2012). [less ▲]

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See detailPolitiques de la littérature : Sartre, Bourdieu, Foucault
Bolmain, Thomas ULg; Cormann, Grégory ULg

Book published by Presses Universitaires de Liège (2015)

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See detailThe origin and control of mega-gullies in Kinshasa (D.R. Congo)
Makanzu Imwangana, Fils; Vandecasteele, Ine; Trefois, Philippe et al

in Catena (2015), 125

This study aims to investigate the relation between mega-gully (> 5 m width) distribution and urbanization in Kinshasa (D.R. Congo), to establish what governs mega-gully location and plan form and to ... [more ▼]

This study aims to investigate the relation between mega-gully (> 5 m width) distribution and urbanization in Kinshasa (D.R. Congo), to establish what governs mega-gully location and plan form and to illustrate the concepts behind mega-gully treatment. For this purpose, the diachronic distribution of mega-gullies has been mapped in Kinshasa. All mega-gullies have been reported in ArcGis 9.3 on the orthorectified SPOT 2007 image. A newly elaborated DEM enables the mega-gullies to be placed in their natural topographical context. The GIS inventory on the SPOT 2006/2007 anaglyph indicates the mega-gully situation in the high town of Kinshasa 5 years ago: 308 mega-gullies with a cumulated length of 94.7 km, a mean drainage density of 0.4 km km− 2 and an average width and depth of 17 m and 6 m respectively. On the WorldView 1 (WV1) coverage, the number of mega-gullies has more than doubled between 2007 and 2010 from 160 to 334. The study shows that mega-gullies only develop within the urbanized perimeter of the high town of Kinshasa and only 5 to 10 years after incipient urbanization. The study also indicates that neither the location, the plan form or the downslope course of mega-gullies in Kinshasa are controlled by the natural topography. Forty-three point eight percent of the mega-gullies in Kinshasa are ‘axial’, occupying urban structures which function as artificial runoff drainage lines: roads, tarred or not, with or without side-road trenches, gutters in all forms and materials from concrete to sand, also foot paths and further all artificial runoff drainage lines. The study reveals that every mega-gully is directly or indirectly induced by human activities, but that every gully also finally ends to grow after an initial phase of sudden development. Mega-gully treatment follows two principles, often combined. The first is to stop the alimentation of the mega-gully head with water. The second includes a complete stabilization of the channel and walls inside the mega-gully. This study emphasizes that gully prevention can basically be achieved by control of the runoff discharges in the artificial stream network, as well as beside the roads. [less ▲]

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See detailResponse of plant functional traits during the restoration of calcareous grasslands from forest stands
Piqueray, Julien; Ferroni, Lucia; Delescaille, Louis-Marie et al

in Ecological Indicators (2015)

In this survey, we studied the response of plant functional traits to calcareous grassland restoration in the Calestienne region, Southern Belgium (restoration protocol: forest clear-cutting followed by ... [more ▼]

In this survey, we studied the response of plant functional traits to calcareous grassland restoration in the Calestienne region, Southern Belgium (restoration protocol: forest clear-cutting followed by grazing at all sites). We considered traits related to dispersal, establishment, and persistence that integrate the main challenges of plants to re-establish and survive in restored areas. Functional traits were compiled from databases and compared among (i) pre-restoration and young restoration forests; (ii) restoration areas of different ages; and (iii) old restorations and reference grasslands. The following questions were addressed: (i) What is the early response (2-4 years) in terms of plant functional trait following one restorative clear-cut event? (ii) What plants functional trait responses occur from restorative management (i.e. sheep and goat grazing)? (iii) Which differences still persist between the oldest restored parcels (10-15 years), and the historical reference grasslands? Forest clear-cuts induced several changes among functional traits, including decreased mean seed mass and certain vegetative traits (i.e. decreased phanerophytes, branching species; and increased short lifespan species i.e. annuals and biennials). During restorative management, clonal, epizoochorous and autumn germinating species were favored. Despite numerous other changes during this phase, many differences remained compared to reference grasslands. In particular, geophytes, mycorrhizal and evergreen species abundance were not approaching reference grassland values. The observed pattern helped to draw inferences on the possible mechanisms operating under vegetation recovery following restorative forest clear-cut and subsequent management were identified and described in this study. Results indicated grazing was an important factor, which increased epizoochorous species, and autumn germinating taxa that filled niches in vegetation opened by summer grazing animals. Finally, differences between old restoration and reference grasslands emphasized that management should focus on reduction in soil fertility, and geophyte rhizomatous grasses. Long-term monitoring is vital to assess if management plans are effective in the complete restoration of species functional trait assemblages. [less ▲]

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See detailReview on greenhouse gas emissions from pig houses: Production of carbon dioxide, methane and nitrous oxide by animals and manure
Philippe, François-Xavier ULg; Nicks, Baudouin ULg

in Agriculture, Ecosystems & Environment (2015)

The environmental impacts of livestock production are attracting increasing attention, especially the emission of greenhouse gases (GHGs). Currently, pork is the most widely consumed meat product in the ... [more ▼]

The environmental impacts of livestock production are attracting increasing attention, especially the emission of greenhouse gases (GHGs). Currently, pork is the most widely consumed meat product in the world, and its production is expected to grow in the next few decades. This paper deals with the production of carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) by animals and by manure from pig buildings, with a focus on the influence of rearing techniques and nutrition. GHG emissions in piggeries originate from animals through CO2 exhalation and CH4 enteric fermentation, and from manure through the release of CO2, CH4 and N2O. The level of the CO2 exhalation (E-CO2, pig) depends on the physiological stage, the body weight (BW), the production level and the feed intake of the animals concerned. Enteric CH4 (E-CH4, pig) is principally related to dietary fibre intake and the fermentative capacity of the pig’s hindgut. Based on a review of the literature, the following equations are proposed in order to estimate E-CO2, pig (in kg day_1) and E-CH4,pig (in g day_1) for fattening pigs: E-CO2, pig = 0.136 _ BW0.573; E-CH4,pig = 0.012 _ dRes; with BW (in kg) and dRes for digestible residues (in g day_1). Numerous pathways are responsible for GHG production in manure. In addition, the microbial, physical and chemical properties of manure interact and modulate the level of emissions. Influencing factors for removal systems for both liquid and solid fractions of manure have been investigated. A large range of parameters showing an impact on the level of GHG production from pig houses has been reported. However, few of these can be considered unquestionably as GHG mitigation techniques because some strategies have shown contradictory effects depending on the gas, the circumstances and the study. Nevertheless, frequent manure removal seems to be an efficient means to reduce concurrently CO2-, CH4- and N2O-emissions from pig buildings for both slatted and bedded floor systems. Manure removal operations may be associated with specific storage conditions and efficient treatment in order to further reduce emissions. Several feeding strategies have been tested to decrease GHG emissions but they seem to be ineffective in reducing emissions both significantly and durably. In general, good management practices that enhance zootechnical performance will have beneficial consequences on GHG emission intensity. Taking into account the results described in the literature regarding CO2-, CH4- and N2O-production from animals and manure in pig houses, we estimate total GHG emissions to 448.3 kg CO2equiv. per slaughter pig produced or 4.87 kg CO2equiv. per kg carcass. The fattening period accounts for more than 70% of total emissions, while the gestation, lactation and weaning periods each contribute to about 10% of total emissions. Emissions of CO2, CH4 and N2O contribute to 81, 17 and 2% of total emissions from pig buildings, representing 3.87, 0.83 and 0.11 kg CO2equiv. per kg carcass, respectively. [less ▲]

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See detailCatalogue of the types and illustrated specimens recovered from the ‘black marble’ of Denée, a marine conservation-Lagerstätte from the Mississippian of southern Belgium
Mottequin, Bernard ULg; Poty, Edouard; Prestianni, Cyrille

in Geologica Belgica (2015)

The Viséan ‘black marble’ of Denée is one of the best preserved Mississippian fossil assemblages. This Lagerstätte is famous for the exceptional preservation of several groups of macro-organisms (fishes ... [more ▼]

The Viséan ‘black marble’ of Denée is one of the best preserved Mississippian fossil assemblages. This Lagerstätte is famous for the exceptional preservation of several groups of macro-organisms (fishes, echinoids, graptolites). However, only a part of the fauna has received attention from specialists and most of the phyla may benefit from a modern revision based on new investigative techniques such as 3D imagery and CT-scanning. Almost all the specimens illustrated in the literature have been traced and we present here a comprehensive catalogue of this material. Representatives of several minor groups are photographically illustrated for the first time as well as five emblematic specimens of the styracopterid genus Benedenius (Pisces). For purposes of nomenclatural formality, the lectotypes of Benedenius deneensis Traquair (in de Koninck, 1878), B. soreili Fraipont, 1890, Oligoporus soreili Fraipont, 1904, Taeniaster? fournieri Fraipont, 1904, and Scaphiocrinus longicaudatus Fraipont, 1904 are here selected. [less ▲]

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See detailWhich psychological factors influence Internet addiction? Evidence through an integrative model
Burnay, Jonathan ULg; Billieux, Joël; Blairy, Sylvie ULg et al

in Computers in Human Behavior (2015), 43

Since the appearance of Internet, several preoccupations have appeared as a result, with Internet addiction being one of the most common. The goals of the present study were two-fold. First, to examine ... [more ▼]

Since the appearance of Internet, several preoccupations have appeared as a result, with Internet addiction being one of the most common. The goals of the present study were two-fold. First, to examine which psychological factors are relevant to explain Internet addiction, including impulsivity, passion and social provision. Second, to incorporate all these factors into an integrative model. Based on multiple regressions and path analysis, results revealed a positive relation between Internet addiction and specific impulsivity components (lack of perseverance, urgency) and obsessive passion. Moreover, positive relations were observed between obsessive passion and reassurance of worth, opportunity for nurturance, sensation seeking and harmonious passion. In other words, Internet addiction is related to obsessive passion, but is explained by different psychological factors. Accordingly, both Internet addiction and obsessive passion can be viewed as two important and complementary facets of problematic Internet use. [less ▲]

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