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See detailAbility of Tuta absoluta (Lepidoptera: Gelechiidae) to develop on alternative host plant species
Bawin, Thomas ULg; Dujeu, David; De Backer, Lara ULg et al

in Canadian Entomologist (2015)

The tomato leafminer, Tuta absoluta Meyrick (Lepidoptera: Gelechiidae), is a widespread devastating pest reported to develop on economically important solanaceous crops. The characterization of its host ... [more ▼]

The tomato leafminer, Tuta absoluta Meyrick (Lepidoptera: Gelechiidae), is a widespread devastating pest reported to develop on economically important solanaceous crops. The characterization of its host range could help to understand and prevent the dispersion behavior of the insect in the environment. In this study, the ability of T. absoluta to develop on 12 cultivated or non-cultivated plants including Solanaceae, Chenopodiaceae, Convolvulaceae, Fabaceae and Malvaceae species under laboratory conditions was assessed. For each plant species, we monitored the development times of immature stages, survival, sex ratios and adult fecundity rates. All the 6 tested non-solanaceous plants, including Chenopodium, Convolvulus and Malva species, were not able to sustain (i.e. allow growth and development) T. absoluta larvae. Among Solanaceae, Solanum species were the most suitable host plants for the pest, but others could be opportunistically colonized with fewer incidences. T. absoluta appears to be strongly related to solanaceous plants which would predominantly support self-sustaining field populations. Preventing crop infestation by removing potential host plants in the immediate field vicinity and culture rotations with non-solanaceous crops is of primary importance. [less ▲]

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See detailUne minorité à la recherche d'elle-même: les Belges germanophones de 1945 à 1973
Brüll, Christoph ULg

Conference given outside the academic context (2015)

Detailed reference viewed: 31 (2 ULg)
See detailA herpesvirus alters the behavior of its host to enhance its replication
Ronsmans, Maygane ULg

Conference (2015, December 18)

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See detailAssessing the Risk of Ecosystem Disruption in Europe using a Dynamic Vegetation Model driven by CMIP5 Regional Climatic Projections from EURO-CORDEX
Dury, Marie ULg; Hambuckers, Alain ULg; Henrot, Alexandra-Jane ULg et al

Conference (2015, December 18)

While the combination of warmer and drier mean climatic conditions can have severe impacts on ecosystems, extreme events like droughts or heat waves that break the gradual climate change can have more ... [more ▼]

While the combination of warmer and drier mean climatic conditions can have severe impacts on ecosystems, extreme events like droughts or heat waves that break the gradual climate change can have more long-term consequences on ecosystem composition, functioning and carbon storage. Hence, it is essential to assess the changes in climatic variability and the changes in frequency of extreme events projected for the future. Ecosystems could not be in a condition to adapt to these new conditions and might be disrupted. Here, the process-based dynamic vegetation model CARAIB DVM was used to evaluate and analyze how future climate and extreme events will affect European ecosystems. To quantify the uncertainties in the climatic projections and in their potential impacts on ecosystems, the vegetation model was driven with the outputs of different regional climatic models (RCMs), nested in CMIP5 GCM projections for the EURO-CORDEX project. We used the ALADIN version 5.3 (Météo-France/CNRM) and other EURO-CORDEX RCMs. These climatic projections are at a high spatial resolution (0.11-degree, ~12 km). CARAIB simulations were performed across Europe over the historical period 1951-2005 and the future period 2006-2100 under RCP4.5 and RCP8.5 emission scenarios. We simulated a set of 99 individual species (47 herbs, 12 shrubs and 40 trees) representing the major European ecosystem flora. First, we analyzed the climatic variability simulated by the climatic models over the historical period and compared it with the observed climatic variability. None of these climatic models can reproduce accurately the present natural climatic variability. Then, to assess the risk of ecosystem disruption in the future and to identify the vulnerable areas in Europe, we created an index combining several CARAIB outputs: runoff, mean NPP, soil turnover, burned area, appearance and disappearance of species. We evaluated the severity of change projected for these variables (period 2071-2100) relative to their current variability (period 1961-1990). Mean changes were considered severe if they exceed observed variability. The highest values of the index were found in southern Europe, indicating that the amplitude of the expected ecosystem changes largely exceeds current interannual variability in this area. [less ▲]

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See detailNumerical and experimental study of the glass flow and heat transfer in the continuous glass fiber drawing process
Chouffart, Quentin ULg; Simon, Philippe; Terrapon, Vincent ULg

in Journal of Materials Processing Technology (2015)

The manufacturing process of glass fibers used for the reinforcement of composite materials consistsin drawing a free jet of a molten glass at high temperature into fibers using a winder. This process is ... [more ▼]

The manufacturing process of glass fibers used for the reinforcement of composite materials consistsin drawing a free jet of a molten glass at high temperature into fibers using a winder. This process is sensitive to numerous disturbances that can cause the fiber to break during the drawing process, and thus reduce the process efficiency. The underlying physics of the forming of a single fiber is investigated here through numerical simulations, and results are validated with measurements obtained on a dedicated experimental unit. Both a two-dimensional axisymmetric and a simplified one-dimensional model are used to simulate the high-temperature region before glass transition. The influence of key parameters and physical mechanisms on the internal stress is investigated through a sensitivity analysis. The simplified model is then used to identify the optimal operating window and to assess the impact of temperature inhomogeneities at the bushing plate. Results show that the initial region close to the tip is critical, and that a low cooling rate reduces the stress. Operating at high tip temperature, large drawing velocity and small tip radius is then found to be the best strategy to minimize the stress. Finally, it is shown that the heat pattern of the bushing plate is one of the most important causes for disturbance in the process. [less ▲]

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See detailCompte rendu - 28th Australian Conference in Banking and Finance
Fays, Boris ULg

Conference (2015, December 18)

Detailed reference viewed: 13 (1 ULg)
See detailReconnaissance et parentification: des mots qui vont si bien ensemble?
Haxhe, Stéphanie ULg

Conference given outside the academic context (2015)

Detailed reference viewed: 43 (4 ULg)
See detailLa terre creuse, de la géologie à la fiction. Postérité d’un chronotope d’anticipation à partir de Jules Verne
Stienon, Valérie ULg

Conference (2015, December 18)

Le voyage au centre de la Terre a été magistralement imaginé par Jules Verne en 1864 avant de devenir un véritable topos de la littérature populaire et de jeunesse. Sa postérité s’illustre dans les ... [more ▼]

Le voyage au centre de la Terre a été magistralement imaginé par Jules Verne en 1864 avant de devenir un véritable topos de la littérature populaire et de jeunesse. Sa postérité s’illustre dans les multiples déclinaisons de la terre creuse, recensées notamment par Guy Costes et Joseph Altairac dans leur bibliographie commentée en 2006. En quoi ce motif plus communément associé à une atemporalité (monde perdu, histoire secrète) ou à une régression temporelle (monde sauvage, vie des cavernes) intervient-il aussi dans une écriture de l’anticipation ? Chez Verne lui-même, il s’agit à la fois d’un voyage à rebours dans le temps, chaque strate parcourue correspondant à un recul historique, et d’une expédition scientifique déployant une technologie et des connaissances novatrices. Ce motif topique semble donc porteur d’une ambiguïté temporelle féconde. La communication proposera un parcours transversal dans le corpus d’anticipation francophone allant d’Ignis (1883) de Didier de Chousy qui traite de l’exploitation d’une nouvelle énergie géothermique, le « feu central de la Terre », jusqu’à Régis Messac dont La Cité des Asphyxiés (1937) dépeint un monde intra-terrestre dystopique. Les reprises de la terre creuse permettent d’éclairer l’importance des filiations génériques, des supports partagés et des formules éditoriales à succès, mais elles mettent aussi en évidence des œuvres atypiques, traduisant de manière spécifique le discours social et scientifique de leur époque. Si Verne, ses épigones et d’autres auteurs d’anticipation ont pu être tentés de réinvestir la terre creuse en fiction à un moment où sa réalité n’est plus perçue comme crédible dans le champ scientifique, c’est sans doute en raison de l’intrication particulièrement dense des disciplines concernées (géographie, géologie, paléontologie, sciences naturelles) et de l’importance des idéologies qui ont pu les croiser et les dynamiser : positivisme, hygiénisme, colonialisme, craintes écologiques. Cette communication voudrait montrer comment le motif fécond de la terre creuse, dans son évolution complexe du plausible à l’irréel, passe d’une croyance à une théorie scientifique avant de se développer en chronotope littéraire. [less ▲]

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See detailEstimation of diet digestibility and intake by grazing ruminants through near infrared reflectance spectroscopy analysis of faeces. Application in various contexts of livestock production
Decruyenaere, Virginie ULg

Doctoral thesis (2015)

Grazing is the most economical feeding scheme for ruminants. Grazing management, however, is often difficult for breeders, particularly because of a lack of knowledge about grass availability and quality ... [more ▼]

Grazing is the most economical feeding scheme for ruminants. Grazing management, however, is often difficult for breeders, particularly because of a lack of knowledge about grass availability and quality. There are methods for assessing the quantitative and qualitative characteristics of grass, but they are difficult to apply in the case of grazing ruminants. Near infrared reflectance spectroscopy (NIRS) is based on the absorption of infrared light by organic matters to provide NIRS spectra. These NIRS spectra can be correlated with the chemical or biological composition of samples in order to develop calibrations that can be used as predictive models. The primary objective of this PhD thesis was to study the potential of NIRS applied to faeces (FNIRS) in order to predict the characteristics of the diets of grazing herbivores. The particular focus was on the in vivo organic matter digestibility, voluntary intake and botanical composition of ingested diets. The main results of the study show that FNIRS has great portential for estimating in vivo digestibility and voluntary intake by grazing ruminants and that faeces are a good indicator of ingested diets. Based on both large or small and varied databases, the results suggest that FNIRS spectral libraries could be developed for characterising ruminant feed intake. The accuracy of the FNIRS models in estimating in vivo digestibility and voluntary intake is similar to or better than that of other methods usually used to assess these parameters. FNIRS could also be used to predict ruminants’ diet composition in terms of plant species. These predictions should be used only for ranking, however, because of the current lack of accurate procedures for determining diet selection individually. NIRS applied to faeces can be used to predict the in vivo characteristics of forage with sufficient accuracy. The prediction error of NIRS calibrations depends on the accuracy and precision of the reference data. The prediction of in vivo digestibility and intake is sufficiently repeatable compared with the procedure using the reference method. Intake is more difficult to predict with sufficient precision and is more closely linked to animal variability and to uncertainty of the FNIRS models. The major difficulty in using this method lies in generating the diet-faecal pairs as reliably as possible. FNIRS calibrations for predicting in vivo diet characteristics are derivative calibrations. The sample analysed for reference values (diet samples) differs from the samples submitted to NIRS analyses (faeces). With regard to research on forages, in vivo trials with animals confined in pens or digestibility crates appears to be the best reference method for generating FNIRS calibrations. Future work will involve developing FNIRS calibrations for predicting independent datasets and using them to create decision-support tools for improving diverse grazing management schemes. The major focus should be to compare different feeding strategies rather than to obtain an exact estimate of feed intake values. As a low-cost and rapid prediction technique, FNIRS could contribute significantly to the development of a methodology that would help improve our knowledge of forage and animal variability. [less ▲]

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See detailWater-Energy Nexus in Shared River Basins: How Hydropower Shapes Cooperation and Coordination
Kouangpalath, Phimthong ULg; Meijer, Karen

in Topical Issue on Sustainability in the Water-Energy-Food Nexus (2015), 2

The construction of hydropower plants on transboundary rivers is seldom done with equal benefits to all riparians, and therefore presents coordination and cooperation challenges. Without a supra-national ... [more ▼]

The construction of hydropower plants on transboundary rivers is seldom done with equal benefits to all riparians, and therefore presents coordination and cooperation challenges. Without a supra-national authority in charge of transboundary river basins, coordination between sectors (water, energy and environment) and cooperation between countries largely depends on willingness of the individual nation states and the power relations between these countries. This paper discusses how the interests and relative power positions of actors in transboundary water management shape the outcomes, and what roles are played by River Basin Organisations and foreign investors (especially in hydropower development). These issues are illustrated with examples from the Mekong river in Southeast Asia (Laos, Thailand, Cambodia and Vietnam), the Euphrates-Tigris (Turkey, Syria, Iraq, Iran and Kuwait) and the Çoruh in Turkey and Georgia. [less ▲]

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See detailEléments de compréhension du processus de radicalisation du point de vue de l'engagement individuel
Garcet, Serge ULg

Conference given outside the academic context (2015)

Detailed reference viewed: 13 (1 ULg)
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See detailSmart point cloud: Toward an intelligent documentation of our world
Poux, Florent ULg; Billen, Roland ULg

Conference (2015, December 17)

A point cloud is the output data of many sensors, such as Lidar and laser scanners, or the processing output from photogrammetry and SFM reconstructions. It is a 3D spatial representation of the ... [more ▼]

A point cloud is the output data of many sensors, such as Lidar and laser scanners, or the processing output from photogrammetry and SFM reconstructions. It is a 3D spatial representation of the environment through thousands, million or billions of points, where each single point as a position in space (X, Y, Z) It is safe to say that today, the technology is ready, and enable us to digitize very quickly the world as it stands. This RAW data is rapidly growing with the autonomous vehicles mapping our roads (LiDAR system equip it) and the robotics field using sensors to evolve in the environment. But how do we use this data? Professionnals have been struggling with point cloud, or delivering it to a client because it looks nice, but is there a real added value to visualization only? Can our clients use it at its full potential? [less ▲]

Detailed reference viewed: 18 (2 ULg)
See detailSur la dialectique, Derrida
Caeymaex, Florence ULg

Conference (2015, December 17)

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See detailNovel organocobalt based on acetylacetonate ligands for the precision synthesis of telechelic polymers
Demarteau, Jérémy ULg; Cordella, Daniela ULg; Kermagoret, Anthony et al

Conference (2015, December 17)

Organocobalt(III) with acetylacetonate ligands is the most representative example of R-Co bearing a weak C-Co bond that can release alkyl radicals under mild experimental conditions without requiring a ... [more ▼]

Organocobalt(III) with acetylacetonate ligands is the most representative example of R-Co bearing a weak C-Co bond that can release alkyl radicals under mild experimental conditions without requiring a photoactivation. The unique isolated specimen is a short oligo(vinyl acetate) end-capped by Co(acac)2. The high lability of the C-Co bond of this R-Co combined to the unique capacity of Co(acac)2 to reversibly trap alkyl radicals make this organocobalt unique for the precision synthesis of unprecedented polymers by the so-called Cobalt-Mediated Radical Polymerization (CMRP) technique. The growth of unstabilized and highly reactive growing radicals formed by the addition of R· to unconjugated olefins (vinyl esters, vinyl amides, vinyl imidazolium, vinyl chloride, ethylene) is controlled by the reversible formation of a weak C-Co bond at the polymer chain end. The lack of alternatives to this R-Co, especially to the structure of the alkyl group, has placed limitations on further innovation in (macro)molecular design. Other functional variants that would enable attractive chain-end derivatizations are unfortunately not available. In this communication, we will address this important challenge by describing an innovative synthetic route towards the preparation of a new functional R-Co(acac)2 that are characterized by a weak C-Co bond. We will report the conditions required for initiating and controlling the radical polymerization of various monomers from these R-Co. We will also demonstrate their utility for the production of novel telechelic polymers under mild experimental conditions, syntheses that can be carried out in water. [less ▲]

Detailed reference viewed: 16 (3 ULg)
See detailUnderwater silence world: the end of the dogma
Parmentier, Eric ULg

Conference (2015, December 17)

Passive acoustics can offer inexpensive, non-invasive and no-destructive means of assessing temporal and spatial patterns in the distribution of individuals engaging in calling. In marine environments ... [more ▼]

Passive acoustics can offer inexpensive, non-invasive and no-destructive means of assessing temporal and spatial patterns in the distribution of individuals engaging in calling. In marine environments, passive acoustic recording methods can be used at depths not accessible to humans, independent of weather conditions, and for a long term. However, these studies have often restricted their investigations to the monitoring of one or two aquatic species. One reason of this loss of information is quite easy to explain: most of the sounds can be detected but cannot be identified. In many families, calling abilities are described in one or two species only although the descriptions of sound producing mechanisms have highlighted other members should be able to make sounds. Since 50 years, sounds were for example described in more or less 40 pomacentrid species but all the 392 species should be able to make sounds. This situation can be more complicated since some species are able to make different kinds of sounds according to the behavioural context. Some call characteristics can also be modulated according to the size in some species only. It shows an important amount of work has to be done to be able to understand the reef soundscape and to develop call recognition software system. [less ▲]

Detailed reference viewed: 19 (1 ULg)
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See detailIndiana Jones sur Mars
Stiepen, Arnaud ULg

Scientific conference (2015, December 17)

Detailed reference viewed: 10 (0 ULg)