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See detailAperçu historique des principales méthodes et approches de l'enseignement des langues étrangères. Notes de synthèse
Simons, Germain ULg

Learning material (2003)

Ce syllabus propose un aperçu historique des principales méthodes d'enseignement des langues étrangères depuis la méthode indirecte ("grammaire-traduction") jusqu'à l'approche communicative. Le 3e ... [more ▼]

Ce syllabus propose un aperçu historique des principales méthodes d'enseignement des langues étrangères depuis la méthode indirecte ("grammaire-traduction") jusqu'à l'approche communicative. Le 3e chapitre de ce document aborde, de manière succincte, la problématique de l'apprentissage des langues en immersion. [less ▲]

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See detailApercu nosologique du spectre des histiocytoses cutanees. Plus ca change, plus c'est la meme chose.
Quatresooz, Pascale ULg; Hermanns-Lê, Trinh ULg; Arrese Estrada, Jorge ULg et al

in Revue Médicale de Liège (2002), 57(11), 715-8

Histiocytes belong to distinct groups of cells. Similarly, histiocytoses represent some pathologic expressions of the various histiocyte lineages recognized by their distinct phenotypes. The recognition ... [more ▼]

Histiocytes belong to distinct groups of cells. Similarly, histiocytoses represent some pathologic expressions of the various histiocyte lineages recognized by their distinct phenotypes. The recognition of four major histiocytosis types relies on the distinction between monocytes-macrophages, dermal dendrocytes, Langerhans cells and the so-called indeterminate cells. Each of these groups exhibits a distinctive clinical and histological presentation. The risk of internal involvement, the prognosis and therapy are different as well. The diagnostic mainly relies on the clinico-pathologic assessment, and more particularly on the combination of histological, immunohistochemical and ultrastructural examinations. [less ▲]

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See detailAperçu palynologique de l'Eodévonien
Steemans, Philippe ULg

Conference (1987)

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See detailAperçu sur les méthodes de dosage des stéroïdes.
Beckers, Jean-François ULg; Ballman, Patricia; Ectors, Francis ULg et al

in Annales de Médecine Vétérinaire (1975), 119

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See detailAperçu systématique, phénologique et biogéographique des Coléoptères Elatérides de Belgique
Jeuniaux, Charles ULg

in Wouters, K.; Baert, L. (Eds.) Invertebraten van België = Invertébrés de Belgique: Verhandelingen van het Symposium "Invertebraten van België" = Comptes rendus du Symposium "Invertébrés de Belgique" = Proceedings of the Symposium "Invertebrates of Belgium" (1989)

The Belgium fauna includes 94 Elaterid species. Their intraspecific variations, phenology and distribution in Belgium were amalysed on the basis of samples collected during 150 years. UTM computed ... [more ▼]

The Belgium fauna includes 94 Elaterid species. Their intraspecific variations, phenology and distribution in Belgium were amalysed on the basis of samples collected during 150 years. UTM computed cartography allowed to describe the localization of every species and, in some cases, to point out some recent tendencies towards regression or expansion of geographic area. [less ▲]

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See detailAperture imaging beyond the classical resolution limit by using incoherent photons
Thiel, C.; Bastin, Thierry ULg; von Zanthier et al

Conference (2008)

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See detailAPH-1, a POU homeobox gene expressed in the salt gland of the crustacean Artemia franciscana
Chavez, Marcela; Landry, Claire; Loret, Suzanne et al

in Mechanisms of Development (1999), 87(1-2), 207-12

We characterized the first POU-homeoprotein in a crustacean (designated APH-1 for Artemia POU-Homeoprotein, EMBL Y15070). The amino acid sequence of the APH-1 POU-domain is identical, except for two ... [more ▼]

We characterized the first POU-homeoprotein in a crustacean (designated APH-1 for Artemia POU-Homeoprotein, EMBL Y15070). The amino acid sequence of the APH-1 POU-domain is identical, except for two residues, to that of the two class III POU proteins Cf1-a (Drosophila) and POU-M1 (Bombyx mori). Southern blot analysis suggests that crustaceans have only one class III POU gene. RT-PCR and whole-mount in situ hybridization show that APH-1 mRNA is present in larvae specifically in the salt gland, an organ which is involved in osmoregulation, and disappears in the adult. [less ▲]

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See detailAphid - phytovirus interactions: investigation of virus binding mechanisms in insect vectors by lectin use and proteomic approach
Yattara, Almouner Ag Alhamis ULg; Véronique Genin, Eric Haubruge; Francis, Frédéric ULg

Poster (2011, July 11)

Aphids are well known for their role in virus transmission to host plant. In some cases, the virus is transmitted from plant to plant simply attached to the cuticule of the mouthparts or the forget. For ... [more ▼]

Aphids are well known for their role in virus transmission to host plant. In some cases, the virus is transmitted from plant to plant simply attached to the cuticule of the mouthparts or the forget. For other, circulative virus transmission based on virion internalization through the aphid gut followed by transfer to salivary glands and finally to next plant during aphid feeding is required. In both situations, presence of receptor components through the digestive tract of the aphids is needed for virus binding and further transmission to next plants even if not localized at the same place. In order to investigate the specific binding of virus on particular aphid receptors, two aphid-virus models were selected to be tested using several lectins showing differential sugar binding specificities. Virus transmission efficacy assays with Myzus persicae and potato virus but also Acyrthosiphon pisum and pea enation mosaic virus were performed using a range of lectins to assess the potential competition of lectins and virus. Some interesting lectins were found to reduce the virus transmission with a 2 fold factor showing potential use of lectin in virus spread control. The aphids were also investigated by a proteomic approach using a two Dimension-Differential in Gel Electrophoresis (2D-Dige) coupled with mass spectrometry to determine the aphid proteins involved in virus transmissions. Head or digestive tubes of aphids were collected and investigated for non persistant or persistant virus models respectively. Differential abilities of aphids to transmit the selected virus models are discussed in relation with lectin affinity specificity and investigated aphid proteins found to be involved in vector-virus interactions. The application of lectin as potential way to reduce virus transmission by aphids will also be developed. [less ▲]

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See detailAphid - symbiont interactions : multitrophic "omic" approaches to investigate multitrophic interactions
Bosquée, Emilie ULg; Bauwens, Julien ULg; Mazzucchelli, Gabriel ULg et al

Poster (2014, August)

« Omics » found recent developments due to significant improvement and availability of both separation and identification methods. For proteomics, functional information’s linked to the studied proteins ... [more ▼]

« Omics » found recent developments due to significant improvement and availability of both separation and identification methods. For proteomics, functional information’s linked to the studied proteins was brought when compared to genomic approach. For these reasons, a panel of tools is available to determine the proteome patterns related to differential adaptation of insects to cope with plant defence mechanisms or to transmit virus. The adaptation and metabolic changes of aphids in relation to host plants focusing on the role of the bacterial endosymbionts was investigated. Use of artificial diet including diverse antibiotics but also the comparison of proteomes related to whole aphid and respective purified bacterial symbionts were studied to identify the respective origin and function of proteins constituting the studied proteomes. Diverse methods including 2D-DIGE, liquid chromatography coupled with mass spectrometry and data bank investigations were developed. From the proteome investigation, characterisation of good and bad virus vectors was also performed in different aphid - plant - virus models. Particular proteins of interest were selected. This broad proteomic approach will be discussed as an interesting and reliable tool to study the biologically involved proteins from aphids in response to several environmental changes [less ▲]

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See detailAphid adaptation to plant defence system
Francis, Frédéric ULg; Harmel, Nicolas ULg; Gerkens, Pascal et al

in Abstract book (2005)

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See detailAphid Alarm Pheromone as a Cue for Ants to Locate Aphid Partners
Verheggen, François ULg; Diez, Lise; Sablon, Ludovic ULg et al

in PLoS ONE (2012)

The mutualistic relationships that occur between myrmecophilous aphids and ants are based on the rich food supply that honeydew represents for ants and on the protection they provide against aphid natural ... [more ▼]

The mutualistic relationships that occur between myrmecophilous aphids and ants are based on the rich food supply that honeydew represents for ants and on the protection they provide against aphid natural enemies. While aphid predators and parasitoids actively forage for oviposition sites by using aphid semiochemicals, scouts of aphid-tending ant species would also benefit from locating honeydew resources by orienting toward aphid pheromone sources. The present study aims to provide additional information on the use of Aphis fabae alarm pheromone, i.e. (E)-β-farnesene (EβF), by ant scouts. The perception and behavioral impact of EβF on Lasius niger were investigated using electroantennography and two bio-assays measuring their attraction and orientation towards aphid semiochemicals. Pronounced electrical depolarizations were observed from L. niger scout antennae to stimulations of A. fabae alarm pheromone, while other sesquiterpenes elicited weak or no responses. L. niger scouts were significantly attracted toward EβF in a four-arm olfactometer, as well as in an two-choice bioassay. These laboratory results suggest for the first time that low amounts of aphid alarm pheromone can be used by L. niger scouts as a cue indicating the presence of aphid colonies and could therefore mediate the aphid-ant partnership in the field. [less ▲]

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See detailAphid alarm pheromone: An overview of current knowledge on biosynthesis and functions
Vandermoten, Sophie ULg; Mescher, Mark C.; Francis, Frédéric ULg et al

in Insect Biochemistry and Molecular Biology (2012), 42

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See detailAphid and plant volatiles induce oviposition in an aphidophagous hoverfly
Verheggen, François ULg; Arnaud, Ludovic; Bartram, Stefan et al

in Journal of Chemical Ecology (2008), 34(3), 301-307

Episyrphus balteatus DeGeer (Diptera, Syrphidae) is an abundant and efficient aphid-specific predator. We tested the electroantennographic (EAG) response of this syrphid fly to the common aphid alarm ... [more ▼]

Episyrphus balteatus DeGeer (Diptera, Syrphidae) is an abundant and efficient aphid-specific predator. We tested the electroantennographic (EAG) response of this syrphid fly to the common aphid alarm pheromone, (E)-beta-farnesene (E beta F), and to several plant volatiles, including terpenoids (mono- and sesquiterpenes) and green leaf volatiles (C6 and C9 alcohols and aldehydes). Monoterpenes evoked significant EAG responses, whereas sesquiterpenes were inactive, except for the aphid alarm pheromone (E beta F). The most pronounced antennal responses were elicited by six and nine carbon green leaf alcohols and aldehydes [i.e., (Z)-3-hexenol, (E)-2-hexenol, (E)-2-hexenal, and hexanal]. To investigate the behavioral activity of some of these EAG-active compounds, E. balteatus females were exposed to R-(+)-limonene (monoterpene), (Z)-3-hexenol (green leaf alcohol), and E beta F (sesquiterpene, common aphid alarm pheromone). A single E. balteatus gravid female was exposed for 10 min to an aphid-free Vicia faba plant that was co-located with a semiochemical dispenser. Without additional semiochemical, hoverfly females were not attracted to this plant, and no oviposition was observed. The monoterpene R-(+)-limonene did not affect the females' foraging behavior, whereas (Z)-3-hexenol and E beta F increased the time of flight and acceptance of the host plant. Moreover, these two chemicals induced oviposition on aphid-free plants, suggesting that selection of the oviposition site by predatory hoverflies relies on the perception of a volatile blend composed of prey pheromone and typical plant green leaf volatiles. [less ▲]

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See detailAphid honeydew is not only a sugary and amino-acid secretion
Leroy, Pascal ULg; Heuskin, Stéphanie ULg; Sabri, Ahmed ULg et al

Poster (2008)

Aphids, feeding from the phloem sap of plants, are the most common honeydew producing insects. This aphid excretory product consists in an aqueous mixture of different chemical compounds of which the most ... [more ▼]

Aphids, feeding from the phloem sap of plants, are the most common honeydew producing insects. This aphid excretory product consists in an aqueous mixture of different chemical compounds of which the most important are sugars (90-95% of the dry weight) and amino acids. This excretory product, used by parasitoids and predators, plays a crucial role in the tritrophic interactions : (1) honeydew is an important food complement and (2) honeydew acts as a volatile and a contact kairomone. These characteristics could be exploited for enhancing the biological control in fields through the use of an « artificial honeydew ». [less ▲]

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See detailAphid honeydew: An arrestant and a contact kairomone for Episyrphus balteatus (Diptera: Syrphidae) larvae and adults
Leroy, Pascal; Almohamad, Raki; Attia, Sabrine et al

in European Journal of Entomology (2014), 111(2), 237-242

Predator searching efficiency increases in response to a variety of environmental cues associated with its prey. The sugary excretion of aphids (honeydew) has been found to act as a prey-associated cue ... [more ▼]

Predator searching efficiency increases in response to a variety of environmental cues associated with its prey. The sugary excretion of aphids (honeydew) has been found to act as a prey-associated cue for many aphid natural enemies. In the present study, the honeydew excreted by Acyrthosiphon pisum (Harris) was identified as an arrestant and a contact kairomone for young larvae and adults of a common predatory hoverfly, Episyrphus balteatus (De Geer) (Diptera: Syrphidae). First and second instar larvae increased their foraging behaviour in the honeydew-treated area. When plants were sprayed with crude honeydew, the speed of movement of female E. balteatus was significantly higher than in controls, resulting in a longer period of time spent on treated plants and laying eggs. We conclude that the honeydew excreted by A. pisum induces searching behaviour and acts as and arrestant not only for adults but also for young E. balteatus larvae. [less ▲]

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See detailAphid host plant and food suitability for aphidophagous larvae: impact on ladybird reproductive performance.
Francis, Frédéric ULg; Haubruge, Eric ULg; Gaspar, Charles ULg

in The BCPC Conference: Pests and diseases, Volume 3. Proceedings of aninternational conference held at the Brighton Hilton Metropole Hotel,Brighton, UK, 13-16 November 2000 (2000)

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