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See detailLeachate and leonardite Humic substances effect on in vitro root initiation and elongation of woody species
Tahiri, Abdelghani ULg; Destain, Jacqueline ULg; Thonart, Philippe ULg et al

Poster (2016, February 05)

Arise from the chemical and biological degradation of plant and animal residues and from the synthetic activities of microorganisms in the soil, humic substances (HS) are natural heterogeneous aromatic ... [more ▼]

Arise from the chemical and biological degradation of plant and animal residues and from the synthetic activities of microorganisms in the soil, humic substances (HS) are natural heterogeneous aromatic and organic compounds. These substances are chemically complex with no clearly defined chemical structure, although generalized models have been proposed. Present everywhere in the nature; they take part in basic functionalities in any ecosystems involving soils, sediments, water and landfills. They have long been recognized as plant growth promoting substances, particularly with regard to influencing nutrient uptake, root growth and architecture. They influence plant productivity directly by the stimulation of biochemical and metabolic processes or indirectly through the modification of soil characteristics and microflora activities. All together, these properties mainly affect root architecture by inducing root hairs proliferation, differentiating root cells and enhancing lateral root emergence. Experiments targeting the rooting stages in absence of interferences were conducted in vitro using HS extracted from landfill leachate and a stable commercial formulation (“Humifirst” from TRADECORP company: 12% humic acid and fulvic acid 3%) issued from leonardite. Shoots and leaves explants of silver birch (Betula pendula Roth) and black alder (Alnus glutinosa L. Gaertn) explants were treated with 10 ppm of leachate and leonardite HS for 5 days during the rooting induction/initiation phase or during rooting elongation phase. The results obtained show that treatment with a low concentration (10 ppm) during induction/initiation phase may be slightly unfavorable to the formation of roots in alder but not in birch. While, in root elongation phase, there is an increase in the number of roots per shoot only in birch. The direct effects of leachate and leonardite HS on root development vary from one species to another. [less ▲]

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See detailComparison of explant responses treated with leachate and leonardite sources of humic substances during in vitro rooting of woody plants.
Tahiri, Abdelghani ULg; Destain, Jacqueline ULg; Thonart, Philippe ULg et al

in Communications in Agricultural and Applied Biological Sciences (2016), 81(1), 158-165

As heterogeneous mixtures of compounds resulting from the physical, chemical and microbiological transformations of organic residues, humic substances (HS) are mostly recognized for their biostimulation ... [more ▼]

As heterogeneous mixtures of compounds resulting from the physical, chemical and microbiological transformations of organic residues, humic substances (HS) are mostly recognized for their biostimulation of plant growth that firstly involve the root development and architecture before further putative improvement of nutrients uptakes. To avoid the interferences currently reported from external origins, the successive steps of rooting have been carried out using shoots and isolated leaves of birch and alder vitro-plants. Extracts issued from landfill leachate (LHS) has been compared to a stable formulation from leonardite ("Humifirst" 12% humic acid 3% and fulvic acid) commercialized by TRADECORP company's (HHS). Chemical analysis showed that LHS source typically contain much higher N (mainly as ammonium (93%) and chloride concentration than HHS. Used at low concentration (10 ppm) during root induction/initiation phase, both HS sources may be slightly unfavorable to the root formation (21% of reduction in primary root number) of alder but not of birch. While, in root elongation phase, there is an increase in the primary root length and lateral root number. The direct effects of HS on in vitro root development vary from one species to another depending on the root treatment stage. Results showed that both explants type response are equivalent in the development of a complete rooting system. [less ▲]

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See detailBien soigner l'arthrose: un enjeu de société
Henrotin, Yves ULg

Conference (2016, February 04)

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See detailIntervenant à la conférence/débat "Les médias et la peur de l'autre"
Hamers, Jérémy ULg

Conference given outside the academic context (2016)

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See detailA family with a split hand malformation
PIERQUIN, Geneviève ULg

Conference (2016, February 04)

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See detailDysmorphology Quiz
BULK, Saskia ULg; PIERQUIN, Geneviève ULg

Conference (2016, February 04)

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See detailAerothermodynamics of Pre-Flight and In-Flight Testing Methodologies for Atmospheric Entry Probes
Sakraker, Isil ULg

Doctoral thesis (2016)

Spacecraft, returning back to Earth, experience a very harsh environment during the encounter with the particles of the atmosphere. One of the major issues of the atmospheric entry is the extreme ... [more ▼]

Spacecraft, returning back to Earth, experience a very harsh environment during the encounter with the particles of the atmosphere. One of the major issues of the atmospheric entry is the extreme aerodynamic heating and the exothermic chemical reactions due to the gas-surface interaction at hypersonic free stream velocities. There is a constant effort by the space agencies to increase the understanding of the re-entry flight dynamics to optimize the spacecraft and especially its thermal protection system design. During the design process, ground tests and numerical tools are extensively used for their low cost and controlled environment abilities. However, real flight tests are indispensable for ground test and numerical tools validation. Due to high costs, such missions are rarely launched and thus there is an increasing interest in small affordable entry probes. Such platforms, once matured enough, may serve as an easily accessible tool to produce experimental data. It is the aim of this dissertation to propose tools to improve ground test capabilities and on the other hand to present the design, and using the developed tools, the testing of aerothermodynamic experimental payloads to collect flight data with a small entry probe. QARMAN (QubeSat for Aerothermodynamic Research and Measurements on AblatioN) is a triple unit CubeSat with ablative and ceramic thermal protection systems. It will perform an atmospheric entry with 7.7 km/s and a peak heat flux of 1.7 MW/m2. The aim of the in-flight experiments is to retrieve real flight data on ablator efficiency (temperature, pressure, recession) and temperature-pressure measurements for transition on the side panels. The peculiar squared geometry of QARMAN led to the development of a Flight-to-Ground Duplication methodology accounting for spacecraft geometries. It allows duplicating fully the stagnation region of a spacecraft with an arbitrary geometry in subsonic plasma wind tunnels. As a requirement of this methodology, free stream characterization techniques, specifically enthalpy measurement techniques are introduced. Experimental and numerical databases are built. A thorough ablation characterization campaign in VKI Plasmatron is conducted to provide input for building material response models. The cork P50 ablator is studied in terms of surface and sub-surface temperatures, emissivity, mass loss, char-pyrolysis layers, outgassing species and recession and swelling profiles. Similar in-flight experiments are proposed for QARMAN flight for in-depth temperature and pressure. Methods to build models for advanced data treatment are proposed. A full picture of post-flight analysis strategy is described for each study to relate the ground tools and flight data. [less ▲]

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See detailMicrodélétions et duplications 22q11.22 distales
PIERQUIN, Geneviève ULg; CABERG, Jean-Hubert ULg; BULK, Saskia ULg

Poster (2016, February 03)

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See detailThe global chemistry climate model ECHAM6-HAMMOZ
Schultz, Martin G.; Franco, Bruno ULg; Kaffashzadeh, Najmeh et al

Poster (2016, February 02)

Atmospheric composition of short-lived gases and aerosols is an important component of the global climate system. Complex processes from emissions, transport, and chemical reactions to heterogeneous loss ... [more ▼]

Atmospheric composition of short-lived gases and aerosols is an important component of the global climate system. Complex processes from emissions, transport, and chemical reactions to heterogeneous loss processes and radiation interactions need to be implemented in climate models to reach an adequate understanding of the role of short-lived climate forcers on the climate system and to allow the assessment of climate impacts on the regional scale. With ECHAM6-HAMMOZ we have developed a comprehensive model of tropospheric and stratospheric aerosols and gas-phase chemistry which is now running successfully on the Jülich supercomputer JURECA. [less ▲]

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See detailArtificial Intelligence and Energy
Cornélusse, Bertrand ULg; Fonteneau, Raphaël ULg

Conference (2016, February 02)

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See detailDeciphering Mars lower atmosphere: Nitric Oxide nightglow seasonal variations as observed by IUVS
Stiepen, Arnaud ULg

Scientific conference (2016, February 02)

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See detailLa Chimie Biologique Industrielle à Gembloux Agro-Bio Tech
Berchem, Thomas ULg; Istasse, Thibaut ULg; Schmetz, Quentin ULg et al

Conference given outside the academic context (2016)

Présentation du laboratoire de Chimie Biologique Industrielle et illustration de nos principales activités; point sur les recherches de trois jeunes doctorants. Leur travail consiste en la valorisation de ... [more ▼]

Présentation du laboratoire de Chimie Biologique Industrielle et illustration de nos principales activités; point sur les recherches de trois jeunes doctorants. Leur travail consiste en la valorisation de matrices biologiques (déchets agricoles, industriels et forestiers,...) pour produire une gamme de nouveaux produits, biocarburants ou molécules chimiques. [less ▲]

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See detailLE PASSÉ, LE PRÉSENT ET L’AVENIR DE LA TRADUCTION AU CAMEROUN
Oumarou Mal Mazou, Rachid ULg

in Atelier de Traduction (2016), n°24

The inactement of institutional bilingualism by the Constitution exposes Cameroon to translation every day, as all official texts/speeches produced in one of the two official languages (French and English ... [more ▼]

The inactement of institutional bilingualism by the Constitution exposes Cameroon to translation every day, as all official texts/speeches produced in one of the two official languages (French and English) must be translated into the other. This translation demand requires translators and training of translators/interpreters becomes compulsory. First Cameroonian translators were initially trained in universities and colleges abroad and later on, after independence, at home when the Advanced School of Translators and Interpreters (ASTI) was created in the mid 1980s. The main objective of the school was to train translators/interpreters for public service. This goal will lapse when the Government decided not to enroll systematically ASTI graduates in 1999. Meanwhile, other private institutes as ISTI of Yaoundé, or programs like those of the University of Yaounde I opened their doors with curricula almost modeled on that of ASTI. Moreover, there is no regulation body for the profession, the only professional associtation that has been existing since the 90s is yet to find its way. This communication aims at looking into the development of translation in Cameroon from independence. Some suggestions are also made towards the future of the profession in one of the few countries where bilingualism is institutional and whereby about 300 local languages interact in a daily basis. [less ▲]

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See detailL'économie du partage
Gautier, Axel ULg

Conference given outside the academic context (2016)

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See detailDecreased antibiotic consumption in the Belgian community: Is it credible?
FRIPPIAT, Frédéric ULg; VERCHEVAL, Christelle ULg; LAYIOS, Nathalie ULg

in Clinical Infectious Diseases : An Official Publication of the Infectious Diseases Society of America (2016), 62(3), 403-404

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See detailFe XXV line profiles in colliding wind binaries
Rauw, Grégor ULg; Mossoux, Enmanuelle; Nazé, Yaël ULg

in New Astronomy (2016), 43

Strong wind-wind collisions in massive binaries generate a very hot plasma that frequently produces a moderately strong iron line. The morphology of this line depends upon the properties of the wind ... [more ▼]

Strong wind-wind collisions in massive binaries generate a very hot plasma that frequently produces a moderately strong iron line. The morphology of this line depends upon the properties of the wind interaction zone and its orientation with respect to the line of sight. As the binary components revolve around their common centre of mass, the line profiles are thus expected to vary. With the advent of the next generation of X-ray observatories (Astro-H, Athena) that will offer high-resolution spectroscopy above 6 keV, it will become possible to exploit these changes as the most sensitive probe of the inner parts of the colliding wind interaction. Using a simple prescription of the wind-wind interaction in an early-type binary, we have generated synthetic line profiles for a number of configurations and orbital phases. These profiles can help constrain the properties of the stellar winds in such binary systems. [less ▲]

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See detailDiversity and ecology survey of mosquitoes potential vectors in Belgian equestrian farms: A threat prevention of mosquito-borne equine arboviruses
Boukraa, Slimane ULg; de la Grandière, Maria Ana ULg; Bawin, Thomas ULg et al

in Preventive Veterinary Medicine (2016), 124

Emergence of West Nile Virus was recently recorded in several European countries, which can lead to severe health problems in horse populations. Europe is also at risk of introduction of mosquito-borne ... [more ▼]

Emergence of West Nile Virus was recently recorded in several European countries, which can lead to severe health problems in horse populations. Europe is also at risk of introduction of mosquito-borne equine alphavirus from Americas. Prevention of these arboviruses requires a clear understanding of transmission cycles, especially their vectors. To characterize mosquito fauna, their ecology and identify potential vectors of equine arboviruses in Belgium, entomological surveys of six equestrian farms located in the Wolloon Region were conducted during 2011–2012. The harvest of mosquitoes was based on larval sampling (272 samples from 111 breeding sites) and monthly adults trapping (CO2-baited traps, Mosquito Magnet Liberty Plus). Among 51,493 larvae and 319 adult mosquitoes collected, morphological identification showed the presence of 11 species: Anopheles claviger (Meigen), An. maculipennis s.l. (Meigen), An. plumbeus (Stephens), Culex hortensis (Ficalbi), Cx. territans (Walker), Cx. pipiens s.l. L., Cx. torrentium (Martini), Coquillettidia richiardii (Ficalbi), Culiseta annulata (Schrank), Aedes cantans (Meigen), Ae. geniculatus (Olivier). Molecular identification of Cx. pipiens species complex allowed the detection of three molecular forms, Pipiens (92.3%), Molestus (4.6%) and Hybrid (3.1%). Larvae of Cx. pipiens sl and Cx. torrentium were omnipresent and the most abundant species. Water troughs, ponds and slurry (liquid manure) were the most favorable breeding sites of mosquito larvae. Based upon behavior and ecology of the identified mosquito species, Studied Belgian equestrian farms seem to provide a suitable environment and breeding sites for the proliferation of potential vectors of arboviruses and those being a real nuisance problem for horses and neighboring inhabitants. [less ▲]

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See detailMeasuring rotation periods of solar-like stars using TIGRE. A study of periodic CaII H+K S-index variability
Hempelmann, A.; Mittag, M.; Gonzalez-Perez, J. N. et al

in Astronomy and Astrophysics (2016), 586

Context. The rotation period of a star is a key parameter both for the stellar dynamo that generates magnetic fields as well as for stellar differential rotation. <BR /> Aims: We present the results from ... [more ▼]

Context. The rotation period of a star is a key parameter both for the stellar dynamo that generates magnetic fields as well as for stellar differential rotation. <BR /> Aims: We present the results from the first year of monitoring a sample of solar-like stars by the TIGRE facility in Guanajuato (Mexico), which will study rotation in solar analogs. <BR /> Methods: TIGRE is an automatically operating 1.2 m telescope equipped with an Échelle spectrograph with a spectral resolution of 20 000, which covers a spectral range of between 3800 and 8800 Å. A main task is the monitoring the stellar activity of cool stars, mainly in the emission cores of the CaII H and K lines. We observed a number of stars with a sampling between 1-3 days over one year. <BR /> Results: A total number of 95 stars were observed between August 1 2013 and July 31 2014, the total number of spectra taken for this program was appoximately 2700. For almost a third of the sample stars the number of observations was rather low (less than 20), mainly because of bad weather. Fifty-four stars show a periodic signal but often with low significance. Only 24 stars exhibit a significant period. We interpret these signals as stellar rotation. For about half of them the rotation periods were already previously known, in which case our period measurements are usually in good agreement with the literature values. Besides the periodic signals, trends are frequently observed in the time series. <BR /> Conclusions: TIGRE is obviously able to detect stellar rotation periods in the CaII H+K emission cores when the time series contains a sufficient number of data points. However, this is frequently not achievable during the wet summer season in Guanajuato. Hence, future estimates of rotation periods will concentrate on stars that are observable during the winter season from October until April. [less ▲]

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