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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 detailThree-Parameter Kinematic Theory for Shear-Dominated Reinforced Concrete Walls: Implementation
Mihaylov, Boyan ULg; Hannewald, Pia; Beyer, Katrin

Software (2015)

The tree-parameter kinematic theory (3PKT) is aimed at addressing the need for physically accurate and computationally effective models for predicting the response of shear-dominated reinforced concrete ... [more ▼]

The tree-parameter kinematic theory (3PKT) is aimed at addressing the need for physically accurate and computationally effective models for predicting the response of shear-dominated reinforced concrete walls. The theory is based on a three-degree-of-freedom kinematic model for the deformation patterns in walls with aspect ratios smaller than approximately 3. In the kinematic model the wall is divided into two parts - a rigid block and a fan of struts - by a diagonal crack. The mechanisms of shear resistance across this crack are modelled with non-linear springs to capture the pre- and post- peak shear behavior of the member. The base section of the wall is also modelled to account for yielding of the reinforcement and crushing of the concrete. The complete formulation of the 3PKT is presented in an ASCE Journal of Structural Engineering paper by Mihaylov, Hannewald and Beyer. The attached Matlab code represents an implementation of the 3PKT for time-efficient computation of the response of shear-dominated walls. The limits of applicability of the 3PKT and the code are defined in the ASCE paper. [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 ▲]

Detailed reference viewed: 47 (4 ULg)
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See detailLe mythe de la donation de sens. Motivation de la noèse par le donné
Leclercq, Bruno ULg

Conference (2015, December 17)

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Peer Reviewed
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)

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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: 83 (8 ULg)
See detailSur la dialectique, Derrida
Caeymaex, Florence ULg

Conference (2015, December 17)

Detailed reference viewed: 8 (0 ULg)
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 ▲]

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See detailSteam Explosion Process
Jacquet, Nicolas ULg; Haubruge, Eric ULg; Richel, Aurore ULg

Scientific conference (2015, December 17)

Detailed reference viewed: 10 (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: 26 (1 ULg)
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See detailIndiana Jones sur Mars
Stiepen, Arnaud ULg

Scientific conference (2015, December 17)

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See detailLa Province de Luxembourg : particularité, histoire et avenir
Grandjean, Geoffrey ULg; Nothomb, Charles-Ferdinand

Conference given outside the academic context (2015)

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See detailToits potagers, bonus immobilier
Jijakli, Haissam ULg

Article for general public (2015)

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See detailTranscriptomic analysis of pancreatic cells in zebrafish
Tarifeño Saldivia, Estefanía ULg

Doctoral thesis (2015)

Pancreas is a mixed gland composed of endocrine and exocrine tissues and plays a crucial role in the metabolism of all vertebrates. The endocrine cells are mainly grouped into the islets of Langerhans and ... [more ▼]

Pancreas is a mixed gland composed of endocrine and exocrine tissues and plays a crucial role in the metabolism of all vertebrates. The endocrine cells are mainly grouped into the islets of Langerhans and secrete distinct hormones, such as glucagon (α-cell), insulin (β-cell), somatostatin (δ-cell) and ghrelin (ε-cell). Diabetes occurs when insulin production by the β-cells is unable to counteract increase of glycemia. The goal of the first part of my thesis was to determine the transcriptomic signatures of each pancreatic cell type in zebrafish in order to identify novel cell type-specific regulatory genes that might be crucial for their differentiation and/or physiology. Pancreatic acinar cells, ductal cells as well as the endocrine α-, β- and δ-cells were isolated from different transgenic adult zebrafish using FACS and RNA-seq was performed from these highly purified cell types. Comparison between the RNA-seq datasets allowed us to highlight all genes (protein coding and non-coding genes) with enriched expression in each cell type and to identify new markers of the mature pancreatic cells in zebrafish. In order to establish the expression blueprint of pancreatic endocrine and exocrine cells conserved from fish to mammals, we compared the pancreatic transcriptomes from zebrafish, mouse and human. Using pancreatic RNA-seq data available in databases, we determined the set of genes displaying enriched expression in endocrine and exocrine cells of human and mouse. Comparison of these data with the zebrafish pancreatic endocrine and exocrine data revealed the genes with conserved expression among vertebrates. Most of the transcription factors previously known to be important for pancreatic cell differentiation are included in this set of conserved genes. This interspecies comparative analysis highlighted genes with evolutionary conserved expression whose pancreatic function is still unknown, but also revealed striking differences in gene expression patterns between species. The goal of the second part of my thesis was to understand the global transcriptional change produced by the loss-of-function of pax6b in pancreatic endocrine cells during pancreas development in zebrafish. We performed RNA-seq from purified pancreatic endocrine cells from wild-type and mutant (pax6b sa0086 null allele) zebrafish embryos at 27 hpf. By comparing the transcriptome of wild-type and mutant endocrine cells, we identified thousands of genes differentially expressed. Notably, we observed that the expression level of the pancreatic hormones was affected as it was reported in murine models. These analyses have revealed the transcriptional network regulated by pax6b in endocrine cells during differentiation. These analyses highlighted many unknown pax6b targets and novel regulators possibly involved in pancreatic function. Future functional analyses will be needed to further investigate the function of the novel regulators identified by this study. [less ▲]

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See detailEcologie et connaissances ethnozoologiques de quelques espèces d'oiseaux gibiers menaces des ecosytèmes du Sud du Bénin
Lougbegnon, Olou Toussaint ULg

Doctoral thesis (2015)

The natural areas of the south of Benin under subequatorial climate are diversified in resident birds’ species as well as migratory one. Some of them are hunted for food and therapeutic purposes by ... [more ▼]

The natural areas of the south of Benin under subequatorial climate are diversified in resident birds’ species as well as migratory one. Some of them are hunted for food and therapeutic purposes by grassroots communities. The most used are Guttera pucherani, Dendrocygna viduata, Egretta alba, Egretta ardesiaca, Porphyrio alleni et Porphyrio porphyrio. In order to reduce pressure on biodiversity in this part of Benin and to implement the sustainable conservation of birds’ species, this study on ecology and ethno-zoological knowledge of hunted bird species was carried out in the forest areas and the Ramsar sites 1017 and 1018. Field prospections were conducted from 2009 to 2012. The birds’ inventory method used was based on listening point techniques of 15 minutes. Data analysis were analyzed through the computation of bird species abundances, the establishment of maps distribution of the species, the habitat description and the modeling of the climatic niche of these species under climatic models CCCMA (Canadian Centre for Climate Modeling and Analysis) and CSIRO (Commonwealth Scientific and Industrial Research Organization) using MAXENT3.3.2. The ethno-zoological knowledge of the birds species were assessed through individual and groups survey and allowed to calculate the use values of the different part of the birds’ species according to the socio-cultural groups, sex and age. Moreover a logistic binary regression was carried out to determine the socio-economic factors which affect bird species exploitation by the grassroots communities. Results of modeling showed that among the variables selected for the prediction of the climatic models, distance from river, altitude appeared as the environmental variable which more contributed to the prediction of the models (with an average of 74.32 % and 12.94%). Projection under CCCMA and CSIRO in 2050, showed a progression of the favorable areas to Dendrocygna viduata, Porphyrio alleni, Porphyrio alleni, Egretta ardesiaca while it showed a regression of the favorable areas to Egretta alba. The estimated uses values showed that the ethno-zoological knowledge on the bird species differed according to the ethnic groups. Birds are used for food, medicinal and magico-mystics purposes. The magico-mystics and food were the most frequent used categories. Homogeneity of knowledge was found among the informants regarding the ethnic group as well as for the sex with respectively 0.66 and 0.7 for the use diversity value (ID) and use equitability value (IE). No significant difference was found between the informant for the use diversity value (ID) and use equitability value (IE). This study helps to build a database on 6 birds’ species and can be used for bird game ranching and game farming in Benin. [less ▲]

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See detailLes débuts du Gravettien dans le Nord-Ouest de l'Europe (28.000 - 26.000 BP)
Touzé, Olivier ULg

Scientific conference (2015, December 16)

Detailed reference viewed: 13 (0 ULg)