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See detailSystème d’exploitation et potentialités économiques des cuvettes oasiennes du sud-est du Niger
Malam Boukar, Awa Krou; Yamba, Boubacar; Lebailly, Philippe ULg

Poster (2016, September 28)

Les cuvettes oasiennes du sud-est nigérien sont sources de production alimentaire (JAHIEL. 1998). C’est pourquoi, les populations locales sont dépendantes des cuvettes pour leurs productions alimentaires ... [more ▼]

Les cuvettes oasiennes du sud-est nigérien sont sources de production alimentaire (JAHIEL. 1998). C’est pourquoi, les populations locales sont dépendantes des cuvettes pour leurs productions alimentaires et leurs revenus (TYCHON B. et al. 2009). Cette étude vise à démontrer l’importance socio-économique des cuvettes oasiennes du sud-est nigérien. [less ▲]

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See detailLa table ronde prospective Horeca en Région de Bruxelles-Capitale
Remy, Céline ULg; Bertrand, Amandine

Scientific conference (2016, September 28)

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See detailComparison of temperature from DTS and ERT with direct measurements during heat tracer experiments in heterogeneous aquifers
Nguyen, Frédéric ULg; Hermans, Thomas ULg; Jamin, Pierre ULg et al

Conference (2016, September 27)

Geothermal field characterization and heat tracer experiments often rely on scarce temperature data collected in boreholes. Electrical resistivity tomography (ERT) and distributed temperature sensing (DTS ... [more ▼]

Geothermal field characterization and heat tracer experiments often rely on scarce temperature data collected in boreholes. Electrical resistivity tomography (ERT) and distributed temperature sensing (DTS) have the potential to provide spatial information on temperature changes in the subsurface. In this contribution, we show how DTS and ERT have been used to investigate the heterogeneity of a heterogeneous aquifer during a heat tracing experiment under forced gradient conditions. Optic fibers were installed in the heat injection well and in two piezometers intersecting the main flow directions at 8 m from the injection well. These piezometers were also equipped with ERT. The DTS measurement in the injection well clearly shows the two-layer nature of the aquifer. After the end of injection, the temperature in the bottom part of the well decreases faster than in the upper part due to the higher water fluxes. Those results are confirmed by DTS measurements in natural flow conditions during a heating wire test. DTS and ERT in the cross-panel both show the vertical and lateral heterogeneity of the aquifer. Temperatures only increase significantly in the bottom part of the aquifer where advection is predominant. However, strong differences are observed laterally. ERT additionally shows that the hot plume is divided in two main flow paths, which is confirmed by direct temperature measurements. The comparison of DTS and ERT shows that one of the well is suffering from water mixing. Indeed, temperature from DTS are homogeneous over the whole tichkness of the aquifer, whereas ERT temperature, less affected by local variations, are varying. Our study demonstrate the value of spatially distributed measurements for the monitoring of heat tracer experiment and highligths the issue of multilevel sampling. The detailed temperature measurements can be subsequently used in hydrogeological model to better estimates heat flow and transport parameters. [less ▲]

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See detailAn old slate mine as lower reservoir for UPSH (Underground Pumping Storage Hydroelectricity)- groundwater interactions and limitations
Bodeux, Sarah ULg; Pujades, Estanislao ULg; Orban, Philippe ULg et al

Conference (2016, September 27)

Renewable energy sources have an increasing role to play in the future energy framework but their intermittence cannot afford a stable production according to the demand. Pumped Storage Hydroelectricity ... [more ▼]

Renewable energy sources have an increasing role to play in the future energy framework but their intermittence cannot afford a stable production according to the demand. Pumped Storage Hydroelectricity (PSH) is an efficient technology to store and release electricity. However, the development of new PSH plants is limited by environmental and topographic constraints. An innovative alternative consists in using old underground mines as lower reservoirs of Underground Pumped Storage Hydroelectricity (UPSH) plants. In this configuration, large amount of water is pumped and injected in underground cavities and these cyclic stresses impact the groundwater system. A hybrid 3D finite element mixing cell method is used to numerically simulate the use of an UPSH facility, in the case of an abandoned slate mine. Different scenarios are computed with varying pumping injection time-sequences. In order to assess the impact on the surrounding groundwater conditions, the resulting head evolution in the cavity and at different distances is analyzed in terms of groundwater oscillation magnitude, drawdown, and seepage into the cavity. Results show clearly the influence of the pumping injection time-sequence (rates, regularity, timing and duration of no-activity periods) on the actual head evolution in the surrounding medium and consequently on the magnitude of interactions with the cavity. For a given hydraulic conductivity of the surrounding medium (i.e. slates in this case study), the main conclusion is that the resulting interaction seepage flows (in and out of the cavity) are highly dependent on the chosen pumping injection sequences. The future impact of UPSH operation must be assessed taking this fact into account. [less ▲]

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See detailLa fluidothérapie chez le bovin adulte
Lecomte, Denis; Casalta, Hélène ULg; Djebala, Salem ULg et al

Conference (2016, September 27)

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See detailDe la crise à l’entreprise, en passant par vous…
Choffray, Jean-Marie ULg

Book published by Amazon, Kindle Edition (2016)

« Si un homme a de la chance, avant de mourir, il rassemblera autant qu'il le peut son patrimoine culturel pour le transmettre à ses enfants. Et jusqu’à son dernier souffle, il sera reconnaissant d’avoir ... [more ▼]

« Si un homme a de la chance, avant de mourir, il rassemblera autant qu'il le peut son patrimoine culturel pour le transmettre à ses enfants. Et jusqu’à son dernier souffle, il sera reconnaissant d’avoir pu laisser cet héritage inépuisable, sachant que c'est notre mère nourricière et notre vie éternelle. » (W. and A. Durant, 1968) « De la crise à l’entreprise, en passant par vous » est une invitation à l’action, à la prise de responsabilité, à la création responsable de valeur économique et à la recherche obstinée d’une croissance rentable. Oui ! Notre monde vient d’échapper à un effondrement systémique dont 1929 n’aurait constitué qu’un aimable préambule. Oui ! L’entreprise privée est le seul acteur social créateur de richesse économique et la solution la plus adaptée au mal qui se répand. Oui ! Il est extrêmement difficile de changer quoi que ce soit sur terre et d’apprendre à dire « non ! » En cas d’échec, le coût est connu : licenciement, exil, condamnation à mort ! L’objet de cet ouvrage est de partager le fruit d’une réflexion menée au cours de ces dernières années sur le rôle de l’entreprise dans l’environnement exceptionnel que nous connaissons depuis la Grande Récession de 2008-2009. Il aborde les causes et les conséquences de cet événement financier, industriel et politique historique ; le rôle de l’entreprise privée, de l’innovation et des entrepreneurs – eh oui ! vous… –, dans la recherche d’une solution ; et, enfin, les principales leçons de l’histoire à la lumière de ce qu’advint de l’œuvre de quelques grands hommes, innovateurs et agents du changement : Steve Jobs, Napoléon Bonaparte, et Jésus de Nazareth. Ecrire sur des thèmes aussi complexes, et aussi lourds de conséquences pour notre devenir commun, est un véritable défi et invite à la modestie. J’espère que les choix effectués mériteront votre investissement, votre attention et votre temps ! [less ▲]

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See detailGenomics and ecological adaptation: metal hyperaccumulation in Arabidopsis halleri
Hanikenne, Marc ULg

Conference (2016, September 27)

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See detailDEVELOPMENT OF NOVEL CATIONIC AND LIGAND-GRAFTED ANIONIC LIPOSOMES FOR BRAIN-TARGETED DRUG DELIVERY
Karim, Reatul ULg; Palazzo, Claudio ULg; Laloy, Julie et al

Poster (2016, September 27)

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See detailInfluence of groundwater exchanges on the efficiency of Underground Pumped Storage Hydroelectricity plants using open pit mines
Pujades, Estanislao ULg; Bodeux, Sarah ULg; Orban, Philippe ULg et al

Poster (2016, September 27)

Underground Pumped Storage Hydropower (UPSH) plants can be used to manage the production of electrical energy according to the demand. These plants consist in two reservoirs, the upper one is located at ... [more ▼]

Underground Pumped Storage Hydropower (UPSH) plants can be used to manage the production of electrical energy according to the demand. These plants consist in two reservoirs, the upper one is located at the surface while the lower one is underground. The energy is stored by pumping water from the lower to the upper reservoir and produced by releasing water from the upper to the lower one. As a result, the hydraulic head in the lower reservoir varies continuously. UPSH plants interact with the surrounding aquifers exchanging groundwater. These groundwater exchanges, which play an important role in the evolution of the hydraulic head inside the underground reservoir, are a fact of concern in the selection of pumps and turbines because their efficiency varies with respect to the head difference between the two reservoirs. Therefore, the aquifer parameters should be considered in the selection of pumps and turbines. In this context, with an UPSH plant made up by an open pit mine, we study numerically (1) the influence of groundwater exchanges on the efficiency and (2) how the hydraulic head evolution varies depending on the aquifer properties. The relation among the groundwater exchanges, the efficiency of pumps and turbines and the aquifer parameters is considered by comparing the numerical results of several simulations. It is shown that groundwater exchanges are not negligible when optimizing the efficiency of UPSH plants. A priori, low hydraulic conductivity geological media were preferred to decrease interactions with the open-pit or the cavity used as lower reservoir. Taking into account the pump/turbine performance curves, it appears that, on the contrary, the global efficiency would be increased if the surrounding medium facilitates large groundwater exchanges because hydraulic head variations are softened. [less ▲]

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See detailClimatic and management drivers of CO2 exchanges by a production crop: Analysis over three successive 4-year crop rotation cycles
Buysse, Pauline ULg; Manise, Tanguy ULg; De Ligne, Anne ULg et al

Poster (2016, September 27)

Carbon dioxide (CO2) exchanges between crops and the atmosphere are influenced by both climatic and crop management drivers. The investigated crop, situated at the Lonzée Terrestrial Observatory (LTO ... [more ▼]

Carbon dioxide (CO2) exchanges between crops and the atmosphere are influenced by both climatic and crop management drivers. The investigated crop, situated at the Lonzée Terrestrial Observatory (LTO, candidate ICOS site) in Belgium and managed for more than 70 years using conventional farming practices, was monitored over three complete sugar beet/winter wheat/potato/winter wheat rotation cycles from 2004 to 2016. Continuous eddy-covariance measurements and regular biomass samplings were performed in order to obtain the daily and seasonal Net Ecosystem Exchange (NEE), Gross Primary Productivity (GPP), Total Ecosystem Respiration (TER), Net Primary Productivity (NPP), and Net Biome Production (NBP). Meteorological data and crop management practices were also recorded. Over the 12 years, NEE was negative (-4.34 kg C m-2) but NBP was positive (1.05 kg C m-2), i.e. as soon as carbon exportation by harvest and carbon importation (manure, slimes) are included in the budget, the site behaves as a carbon source. At the crop rotation scale (4 years) it was quite remarkable to observe that NBP was very similar over the three rotations (0.30-0.36 kg C m-2), despite climatic and management differences between years. Crop type impacted carbon exchanges, with sugar beet and winter wheat crops leading to higher net carbon sequestration than seed potato crops. For one given crop, larger growth length and cumulated global radiation drove larger cumulated NEE. Net carbon emissions were observed during intercrops, but growing mustard during these periods reduced their rates and provided carbon residues to the soil. NBP values suggest that one sixth of the total soil organic carbon stock at LTO (6.23 ± 0.16 kg C m-2 in [0, 60] cm) would be lost in 12 years. Large uncertainties (mostly due to biomass measurements) affect NBP estimates, but still, this figure is huge and should encourage cultural practices returning carbon to the soil. [less ▲]

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See detailOccurrence of greenhouse gases (CO2, N2O and CH4) in groundwater of the Walloon Region (Belgium)
Jurado Elices, Anna ULg; Borges, Alberto ULg; Hakoun, Vivien et al

Conference (2016, September 27)

Carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) can be indirectly transferred to the atmosphere through groundwater discharge into surface water bodies such as rivers. However, these emissions ... [more ▼]

Carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) can be indirectly transferred to the atmosphere through groundwater discharge into surface water bodies such as rivers. However, these emissions are poorly evaluated and highly uncertain. The aim of this work is identify the hydrogeological contexts (alluvial, sandstone, chalk and limestone aquifers) and in situ conditions which are most conducive to the generation and occurrence of GHGs in groundwater at a regional scale. To this end, CO2, CH4 and N2O concentrations as well as major and minor elements were monitored (n=37 samples) in two field campaigns (09/2014 and 03/2015) in 15 groundwater bodies of the Walloon Region (Belgium). This preliminary work, which was presented in the 42st IAH conference (Rome, Italy), shown that GHG concentrations range from 5,160 to 47,544 ppm from the partial pressure of CO2 and from 0 to 1,064 nmol/L and 1 to 5,637 nmol/L for CH4 and N2O respectively. Overall, groundwater was supersaturated in GHGs with respect to atmospheric equilibrium, suggesting that groundwater contribute to the atmospheric GHGs budget. A third sampling campaign is carried out in 2016 including around 60 new groundwater samples. The combination of the results of the three campaigns allows: (1) reducing the uncertainties related to indirect emissions of GHG through groundwater-surface water interaction and (2) contributing to a better understanding of the occurrence of GHGs in aquifers. New results will be presented and discussed in detail in the presentation. [less ▲]

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See detailMécanismes moléculaires associés à l’induction de la pathogénicité chez Streptomyces scabies
Jourdan, Samuel ULg

Doctoral thesis (2016)

Streptomyces are filamentous soil-dwelling bacteria that actively participate in the mineralization of dead organic matter. Members of this bacterial genus are commonly known for the plethora of secondary ... [more ▼]

Streptomyces are filamentous soil-dwelling bacteria that actively participate in the mineralization of dead organic matter. Members of this bacterial genus are commonly known for the plethora of secondary metabolites of interest they secrete. Predominantly saprophytes, some Streptomyces species have been proved to be phytopathogenic. The most widespread and best characterized of these species is Streptomyces scabies which is the causative agent of the common scab disease that affects the underground organs of many plants with a preference for storage organs such as potato tubers or pivot roots (beet, turnip, carrot, etc.). Common scab is characterized by brown and corky lesions on the infected organs and causes significant economic losses around the world. The pathogenicity of S. scabies is directly related to its ability to produce the phytotoxin thaxtomin. Unveiling when, how and why S. scabies triggers the production of its phytotoxin is therefore of major interest to understand phytopathogenicity and the virulence associated with this bacteria. Previous works identified cellobiose as the main elicitor of thaxtomin production. However, no signaling pathway from the sensing of the eliciting signal to the biosynthesis of thaxtomin has been proposed so far. The aim of this work is to elucidate the molecular mechanisms involved in the onset of thaxtomin production in the model species S. scabies. In this work we highlighted the central role of the cellulose utilization transcriptional repressor CebR in S. scabies pathogenicity. Indeed, we showed that this regulator directly controls the expression of thaxtomin biosynthesis genes, but also the expression of genes involved in sensing, transport and catabolism of cellooligosaccharides. Together, our results allow to propose a first signaling pathway from cellooligosaccharide transport to the production of thaxtomin in S. scabies, with each step of the cascade controlled by CebR. The results obtained in the course of this thesis extended well beyond the fundamental research scope of elucidating the mechanisms associated with the onset of virulence of S. scabies. Indeed, assessed if/how our findings could propose solutions to current industrial biotechnology iapplications, i.e. i) to provide a mutant that constitutively produce thaxtomine could improve the production yields of this promising bioherbicide, and ii) to assess the enzymatic characteristics of a Beta-glucosidase of S. scabies as possible candidate in lignocellulose saccharification processes. [less ▲]

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See detailInvestir ou mourir, il faut choisir…
Choffray, Jean-Marie ULg

Book published by Amazon, Kindle Edition (2016)

Investir : c’est croire en l’avenir. C’est renoncer en partie au présent pour donner vie au futur. C’est tourner le dos aux « bouffeurs d’espoir » et à l’illusoire confort du statu quo. Enfin, et surtout ... [more ▼]

Investir : c’est croire en l’avenir. C’est renoncer en partie au présent pour donner vie au futur. C’est tourner le dos aux « bouffeurs d’espoir » et à l’illusoire confort du statu quo. Enfin, et surtout, c’est oser « oser » ! La distance séparant le discours public de la performance économique avérée suffit à démontrer l’incompréhension des mécanismes de création de richesse de ceux qui sont censés en avoir la maîtrise et/ou les mettre en œuvre. Il est peu de domaines où les illusions, et autres idées fausses, ont un succès tel qu’elles amènent à s’interroger sur le profit que d’aucuns pourraient en tirer… L’objet de cet ouvrage est de partager le fruit d’une réflexion menée sur le thème de l’investissement, forme proéminente et condition première de l’activité économique, au moment où certains s’interrogent sur son encadrement et cherchent à en limiter la liberté. Il aborde les bouleversements technologiques les plus significatifs ; l’art et la science d’investir avec Internet ; la recherche d’opportunités nouvelles ; et, se termine par quelques observations et souhaits quant à « l’état » du monde ! [less ▲]

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See detailOn the GMP production of [18]FUCB-H : Imaging neurotransmission
Warnier, Corentin ULg

Doctoral thesis (2016)

We herein describe the straightforward synthesis of a stable pyridyl(aryl)iodonium salt and its [18F]radiolabelling within a one-step, fully automated and cGMP compliant radi-osynthesis of [18F]UCB-H, a ... [more ▼]

We herein describe the straightforward synthesis of a stable pyridyl(aryl)iodonium salt and its [18F]radiolabelling within a one-step, fully automated and cGMP compliant radi-osynthesis of [18F]UCB-H, a PET tracer for the imaging of Synaptic Vesicle glycoprotein 2A (SV2A). Over the course of one year, 40 automated productions provided 34±2% of injectable [18F]UCB-H from up to 7.7 Ci of [18F]fluoride in 50 minutes (uncorrected radiochemical yield. Specific Activity = 22±5 Ci/µmol). The successful implementation of our synthetic strategy within routine, high-activity and cGMP productions attests to its practicality and reliability for the production of large doses of [18F]UCB-H. In addition to enabling efficient and cost-effective clinical research on a range of neurological pathologies through the imaging of SV2A, this work further demonstrates the real value of iodonium salts in the cGMP 18F-PET tracer manufacturing industry and their ability to fulfill practical and regulatory requirements in that field. [less ▲]

Detailed reference viewed: 42 (8 ULg)
See detailRelectures de La Misère du monde: Bourdieu, Sartre, Enzensberger
Cormann, Grégory ULg

Conference (2016, September 26)

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