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See detailCyanobacterial diversity at Utsteinen: The impact of the “zero emission” research station in Antarctica
Fernandez Carazo, Rafael ULg; Ertz, Damien; Wilmotte, Annick

Poster (2007, October 11)

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See detailCyanobacterial diversity for an anthropogenic impact assessment in the Sor Rondane Mountains area, Antarctica
Fernandez-Carazo, Rafael; Namsaraev, Zorigto; Mano, Marie-José ULg et al

in Antarctic Science (2012), 24(3), 229-242

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See detailCyanobacterial Diversity In Antarctic Aquatic Microbial Mats
Stelmach Pessi, Igor ULg; Lara, Yannick ULg; Durieu, Benoit ULg et al

Poster (2016, September 08)

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See detailCyanobacterial diversity in natural and artificial microbial mats of Lake Fryxell (McMurdo dry valleys, Antarctica): A morphological and molecular approach
Taton, A.; Grubisic, Stana ULg; Brambilla, E. et al

in Applied and Environmental Microbiology (2003), 69(9), 5157-5169

Currently, there is no consensus concerning the geographic distribution and extent of endemism in Antarctic cyanobacteria. In this paper we describe the phenotypic and genotypic diversity of cyanobacteria ... [more ▼]

Currently, there is no consensus concerning the geographic distribution and extent of endemism in Antarctic cyanobacteria. In this paper we describe the phenotypic and genotypic diversity of cyanobacteria in a field microbial mat sample from Lake Fryxell and in an artificial cold-adapted sample cultured in a benthic gradient chamber (BGC) by using an inoculum from the same mat. Light microscopy and molecular tools, including 16S rRNA gene clone libraries, denaturing gradient gel electrophoresis, and sequencing, were used. For the first time in the study of cyanobacterial diversity of environmental samples, internal transcribed spacer (ITS) sequences were retrieved and analyzed to complement the information obtained from the 16S rRNA gene. Microscopy allowed eight morphotypes to be identified, only one of which is likely to be an Antarctic endemic morphotype. Molecular analysis, however, revealed an entirely different pattern. A much higher number of phylotypes (15 phylotypes) was found, but no sequences from Nodularia and Hydrocoryne, as observed by microscopy, were retrieved. The 16S rRNA gene sequences determined in this study were distributed in 11 phylogenetic lineages, 3 of which were exclusively Antarctic and 2 of which were novel. Collectively, these Antarctic sequences together with all the other polar sequences were distributed in 22 lineages, 9 of which were exclusively Antarctic, including the 2 novel lineages observed in this study. The cultured BGC mat had lower diversity than the field mat. However, the two samples shared three morphotypes and three phylotypes. Moreover, the BGC mat allowed enrichment of one additional phylotype. ITS sequence analysis revealed a complex signal that was difficult to interpret. Finally, this study provided evidence of molecular diversity of cyanobacteria in Antarctica that is much greater than the diversity currently known based on traditional microscopic analysis. Furthermore, Antarctic endemic species were more abundant than was estimated on the basis of morphological features. Decisive arguments concerning the global geographic distribution of cyanobacteria should therefore incorporate data obtained with the molecular tools described here. [less ▲]

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See detailCyanobacterial diversity in soil crusts in the Sör Rondane Mountains
Namsaraev, Zorigto; Mano, Marie-José; Wilmotte, Annick ULg

Poster (2016, August)

Antarctica is the only continent that is dominated by microbial (cyanobacteria and algae) and lower plant (predominantly mosses and lichens) communities. Cyanobacteria are photosynthetic bacteria that ... [more ▼]

Antarctica is the only continent that is dominated by microbial (cyanobacteria and algae) and lower plant (predominantly mosses and lichens) communities. Cyanobacteria are photosynthetic bacteria that require solar light, liquid water, air and some mineral nutrients for growth. They serve as primary producers of organic matter in Antarctic ecosystems providing energy to other physiological groups of microorganisms and invertebrates. Cyanobacteria form macroscopically visible crusts or thin biofilms on the surface of soils and rocks, or occupy endolithic niches in Antarctic mountains. Mountains exposed above the ice sheet could have remained ice-free during glaciation maxima in Antarctica. They could serve as a refuge for terrestrial biodiversity and potential source for recolonization of surrounding habitats during glacier retreat. Cyanobacterial diversity in habitats located above 1 km a.s.l. was studied in several Antarctic locations. These include: the Vinson Massif in Ellsworth Mountains (2000-2500 m a.s.l.), Beacon (1176 m a.s.l.) and University Valleys (1700 m a.s.l.) in the "stable upland zone" of the McMurdo Dry Valleys (Southern Victoria Land) and the Sör Rondane Mountains (1370-1700 m a.s.l.) (Yergeau et al., 2007; Wood et al., 2008; Fernandez-Carazo et al., 2012). The goal of our work was to study cyanobacterial diversity of cyanobacteria in the Sör Rondane Mountains in the vicinity of Belgian Princess Elisabeth Station. Previous estimates of the diversity showed the presence of 10 morphotypes and 13 OTUs of cyanobacteria in 10 samples of biofilms and microbial crusts (Fernandez-Carazo et al., 2012). We performed a broader sampling and studied cyanobacterial diversity using DGGE with cyanospecific primers and microscopy. In 126 samples, we observed 15 morphotypes of cyanobacteria. 28 representative samples were selected for molecular analyses that revealed the presence of 28 OTUs (groups of 16S rRNA sequences sharing at least 97,5% sequence similarity). Comparison with other mountainous areas of Antarctica showed that the Sör Rondane Mountains harbor a significantly higher cyanobacterial diversity. Molecular analysis of the cyanobacterial diversity in Beacon Valley didn't show the presence of cyanobacteria (Wood et al., 2008), though a strain of Chroococcidiopsis sp. (CCMEE 134) was isolated from a sample collected there (Billi et al., 2011). A strain of Chroococcidiopsis sp. (CCMEE 171-A789-2) was also isolated from samples collected in University Valley (Cumbers & Rothschild, 2014). 5 OTUs of cyanobacteria were detected in samples collected in Ellsworth Mountains despite of the presumably harsher climate (78°31′S latitude compared to 77°49′S for Beacon Valley) and higher altitude (Yergeau et al., 2007). No reliable climate data are available for the discussed areas, except for the Sor Rondane Mountains. We propose that the higher diversity of cyanobacteria detected near the Princess Elisabeth Station could be explained by a more intensive sampling or by a more northern location of the area (72°0′S). [less ▲]

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See detailCyanobacterial diversity in the Transantarctic Mountains (Antarctica).
Fernandez Carazo, Rafael ULg; Hodgson, Dominic; Wilmotte, Annick

Poster (2008, August 31)

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See detailCyanobacterial sequences retrieved directly from the Great Sippewissett Salt Marsh, MA, USA
Dillon, Jesse; Wilmotte, Annick ULg

in Bulletin de l'Institut Océanographique. Numéro spécial (1999), 19

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See detailCyanobacterial 
molecular 
diversity 
and distribution 
in 
microbial 
mats from 
antarctic 
lakes
De Carvalho Maalouf, Pedro ULg; Lambion, Alexandre ULg; Zakhia, Frédéric et al

Poster (2009, December 11)

The coastal deglaciated areas of Antarctica hold lakes and other water bodies with a wide spectrum of limnological conditions. Aquatic habitats offer milder conditions to the microorganisms, which are the ... [more ▼]

The coastal deglaciated areas of Antarctica hold lakes and other water bodies with a wide spectrum of limnological conditions. Aquatic habitats offer milder conditions to the microorganisms, which are the only permanent inhabitants of this glacial desert. Among them, cyanobacteria are the first photosynthetic colonisers, sometimes forming thick, cohesive and pigmented benthic mats. In the frame of the BELSPO AMBIO project (Antarctic Microbial BIOdiversity, influence of geographical and ecological factors, www.ambio.ulg.ac.be), we have obtained benthic mat samples coming from lakes from various coastal regions of the continent (MERLIN 2007 and BELARE 2007 field campaigns and by collaborations). We have investigated cyanobacterial molecular diversity via Polymerase Chain Reaction and Denaturating Gradient Gel Electrophoresis (PCR-DGGE) on a set of 80 samples. We couple the numerical analysis of the obtained band patterns with the phylogenetic analysis of the sequences, and by using multivariate analysis, we will assess the role of the ecological and geographical factors shaping the distribution and the diversity of cyanobacteria. Preliminary results of the analysis of 13 samples seem to indicate that lakes separated by a small distance have different cyanobacterial communities, highlighting the importance of ecological factors. Fifty per cent of the obtained Operational Taxonomic Units (OTUs) are potentially endemic to Antarctica while others seem to have a global distribution. The completed study will give us a wide scale view on the distribution and the diversity of cyanobacteria in two biogeographical zones: Continental Antarctica and Maritime Antarctica. Finally, our studies will supply new data and arguments for the ongoing “everything is everywhere, but the environment selects” debate concerning microbial biogeography. [less ▲]

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See detailThe ‘cyanobiome’ of Svalbard, High Arctic
Stelmach Pessi, Igor ULg; Laughinghouse, H Dail; Velazquez, David et al

Poster (2016, October 28)

Over the last decades, the Arctic has experienced a warming trend that is nearly twice as high as the global average, a phenomenon known as ‘Arctic amplification’. The impact of warmer temperatures on ... [more ▼]

Over the last decades, the Arctic has experienced a warming trend that is nearly twice as high as the global average, a phenomenon known as ‘Arctic amplification’. The impact of warmer temperatures on Arctic ecosystems is still unclear. Cyanobacteria are the key primary producers in freshwater and terrestrial Arctic ecosystems, where they are the driver for numerous ecological functions. For a better understanding of the impacts of climate change on Arctic ecosystems, baseline knowledge on cyanobacterial diversity and distribution is crucial. Here we investigate, for the first time, the biogeographic patterns of cyanobacterial communities across Svalbard, using 454 pyrosequencing of partial 16S rRNA gene sequences. Samples were taken from distinct ecosystems and biogeographic zones. We also compare the studied communities with similar Antarctic communities. [less ▲]

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See detailThe cyanophyte Arthrospira fusiformis from Mozambique, Africa: Morphological and molecular characterization
Mussagy, Aidate; Wilmotte, Annick ULg; Cronberg, Gertrud

in Algological Studies (2006), 121

The morphology and the Internally Transcribed Spacer sequences of two Arthrospira (Cyanobacteria) strains with tightly coiled and loosely coiled trichome, isolated from waste water treatment ponds in ... [more ▼]

The morphology and the Internally Transcribed Spacer sequences of two Arthrospira (Cyanobacteria) strains with tightly coiled and loosely coiled trichome, isolated from waste water treatment ponds in Maputo, Mozambique, were investigated. According to the accepted traditional classification the tightly coiled strains were assigned as Arthrospira fusiformis and the loosely coiled as Arthrospira maxima. In both clonal cultures, initiated from a tightly coiled (strain 1) or a loosely coiled trichome (strain 2), different variants arose, in which the tightly coiled forms were more lax than the inoculated cloned trichomes, and loosely coiled forms became tightly coiled. In both cultures, different transient forms appeared, and even straight trichomes were observed. The straight form (variant 1) was isolated and cultivated under different light intensities. After two months, this straight form had not changed into coiled trichomes. However, the trichomes obtained after growth of the hormogonia of the straight trichomes contained a mixture of loosely coiled and straight trichomes.On the basis of the morphological analysis of Arthrospira, it is evident that the degree of coiling is highly variable, which creates uncertainty when used to define the different species. The DNA from the two clonal strains 1 and 2 was isolated and a part of the rRNA operon (including the 3' end of the 16S rRNA gene and the Internally Transcribed Spacer) was determined after amplification by PCR using specific primers. The two ITS sequences were identical and belonged to the subcluster I.A., as defined by Baurain et al. (2002). Variant 1 gave also an identical ITS sequence. A PCR to test the presence of mcyE, a gene involved in the synthesis of the microcystin synthetase, was negative for the two strains and the variant 1. This study showed that for a reliable identification of Arthrospira species, information from specimens collected in the field, cultured strains, developmental stages, and molecular analysis, should be combined. [less ▲]

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See detailCyanures et thiocyanates en toxicologie hospitalière
Charlier, Corinne ULg; Gougnard, Th; Lamiable, D. et al

in Annales de Toxicologie Analytique (2000), XII(2), 131-136

Cyanide is a highly toxic poison, able to very rapidly induce the death. Thiocyanate anion (SCN-) is a metabolic product of cyanide and cyano-containing organic substances, produced by two major enzymes ... [more ▼]

Cyanide is a highly toxic poison, able to very rapidly induce the death. Thiocyanate anion (SCN-) is a metabolic product of cyanide and cyano-containing organic substances, produced by two major enzymes : thiosulfate sulfure transferase and β mercaptopyruvate transsulfurase. Determinations of blood cyanide is important to confirm the diagnostic of intoxication. A survey of methods for the quantitative determination of cyanide and thiocyanate in biological matrices is presented. Particular attention is paid to the rapidity and to the sensitivity of the method. [less ▲]

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See detailCyber-pédopornographes : fixation pédophilique et Internet, une alternative à risque ?
Glowacz, Fabienne ULg; Galligani, Lucas; Hennen, Clarisse

Poster (2015, June)

La consommation de pédopornographie est un thème de recherche récent faisant suite à l’intérêt scientifique et clinique porté à la délinquance sexuelle. La question des rapports entre l’existence d’une ... [more ▼]

La consommation de pédopornographie est un thème de recherche récent faisant suite à l’intérêt scientifique et clinique porté à la délinquance sexuelle. La question des rapports entre l’existence d’une fixation pédophilique, la consommation de pédopornographie et les passages à l’acte pédophilique a été abordée par plusieurs études (Bourke et Hernandez, 2009 ; Babchishin, Hanson et Herman, 2010 ; Corriveau et Fortin, 2014) et reste en débat. Selon l’article 383bis du code pénal belge, la pédopornographie consiste en des « emblèmes, objets, films, photos, diapositives ou autres supports visuels présentant des mineurs d’âge dans des positions à caractère sexuel ». Cependant, le point de vue légal ne permet pas de prendre en considération tous les supports que peuvent utiliser les pédopornographes. En effet, certains amateurs trouveront satisfaction dans des contenus non-pornographiques. Dès lors, une typologie des images utilisées par les amateurs de pornographie enfantine a été mise en place par Taylor, Holland et Quayle (2001), sous le nom de COPINE Scale, reprenant dix catégories d’images pouvant être consultées ou téléchargées par les amateurs. Il existe différents lieux sur l’Internet sur lesquels ces supports se trouvent, le plus important étant les groupes de nouvelles, mais aussi plusieurs systèmes, comme que le peer-to-peer, dans lesquels les échanges de telles images s’opèrent. Plusieurs typologies ont été élaborées (Fortin et Roy, 2003 ; Delmonico et Griffin, 2008 ; Davidson, 2008 ; Corriveau et Fortin, 2011) identifiant divers profils : collectionneurs, distributeurs, abuseurs, producteurs et commerçants. Dans le cadre de notre recherche, à partir d’entrevues menées avec 9 sujets consommateurs de pédopornographie (âgés entre 29 et 60 ans) consultant au centre de santé mentale SYGMA, équipe de santé spécialisée, (8 d’entre eux dans le cadre d’une mesure judiciaire), nous avons exploré plusieurs dimensions pouvant être associées aux conduites de consommation de pédopornographie : l’addiction à internet, la présence d’une fixation pédophilique, la tendance à l’ennui, l’impulsivité et la recherche de sensation, la présence d’un soutien social ainsi que le rôle de sous-cultures pédopornograhiques. Au niveau méthodologique, nous avons adopté une approche mixte basée sur un entretien semi-structuré et la passation de tests (Echelle de provision sociale, Caron, 1996 ; Echelle de disposition à l’ennui, Gana et Akrmi, 1988 ; Implusive Behavior Scale, Whiteside et Lynam, 2001 ; Mesure de l’intensité des conduites addictives appliquée à l’internet, Décamps, Battaglia, et Idier, 2010) et sur une analyse du dossier clinique comprenant les jugements, les avis motivés et les entretiens cliniques. Nos résultats indiquent que la fixation pédophilique pouvait être un moteur de la consommation sans pour autant être présente chez tous les sujets. La tendance à l’ennui est une dimension peu signifiante dans la dynamique de consommation. Ce sont le manque de soutien social et l’insatisfaction affective et sexuelle qui se retrouvent au centre des dynamiques de la consommation pédopornographique de nos sujets. Isolés socialement et présentant un développement problématique sur le plan sexuel et affectif, c’est notamment par la consommation de pédopornographie que les sujets disent avoir trouvé une alternative. Cette consommation renvoie par ailleurs à un manque de contrôle social, offrant l’opportunité de consommer, ainsi qu’une impossibilité d’identifier un partenaire sexuel. L’Internet sera alors vu comme un outil permettant de répondre à ces difficultés sexuelles, sans pour autant qu’il n’y ait de comportement addictif. [less ▲]

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See detailLes cyber-taureaux des vétérinaires liégeois
Durand, Pascal ULg

Article for general public (1996)

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See detailCyberactivistes et société civile. Les ambigüités de la révolution tunisienne
Lecomte, Romain ULg

Article for general public (2011)

On a beaucoup parlé d’Internet dans la révolution tunisienne, mais les cyberactivistes ont principalement joué un rôle de relai et il ne faudrait pas sous-estimer par ailleurs les efforts d’une société ... [more ▼]

On a beaucoup parlé d’Internet dans la révolution tunisienne, mais les cyberactivistes ont principalement joué un rôle de relai et il ne faudrait pas sous-estimer par ailleurs les efforts d’une société civile organisée certes fragile mais dont le savoir-faire militant fut décisif. Dans la reconfiguration actuelle de l’espace public tunisien, réseaux sociaux et nouveaux médias peuvent tenir une place importante, mais qui n’est pas sans ambiguïté. [less ▲]

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See detailCybercontestation tunisienne
Lecomte, Romain ULg

Article for general public (2011)

Les récents soulèvements arabes ont conduit nombre de journalistes et experts à se focaliser sur le rôle décisif d'Internet dans les mobilisations. Autant les usages contestataires d'Internet dans le ... [more ▼]

Les récents soulèvements arabes ont conduit nombre de journalistes et experts à se focaliser sur le rôle décisif d'Internet dans les mobilisations. Autant les usages contestataires d'Internet dans le monde arabe étaient jusque là largement ignorés, par les médias traditionnels (occidentaux ou non) mais aussi par le monde académique, autant désormais on observe une surenchère sur le rôle révolutionnaire des médias sociaux, souvent agrémentés de titres accrocheurs : « Révolution 2.0. », « Révolution Facebook », « Cyber-révolution »... À partir d'une recherche de doctorat portant sur les usages citoyens et contestataires d'Internet par les Tunisiens, je souhaiterais ici apporter un éclairage plus nuancé sur le rôle d'Internet dans ce petit pays du Maghreb où le « printemps arabe » est né, en prenant en considération à la fois son importance et ses limites. Je commencerai par poser le contexte contraignant dans lequel les internautes tunisiens devaient évoluer sous le régime de Ben Ali. Ensuite, je retracerai l'évolution des usages citoyens et contestataires d'Internet depuis la fin des années 90 jusqu'à aujourd'hui. Enfin, à la lumière de cette courte mais déjà riche histoire, je proposerai quelques éléments d'analyse du rôle d'Internet dans la conjoncture critique de décembre 2010-janvier 2011 en Tunisie. [less ▲]

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See detailCybercriminaliteit: materieel- en procedureelrechtelijke aspecten
Franssen, Vanessa ULg

Conference given outside the academic context (2017)

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See detailCYBERDEPENDANCE : MYTHE OU REALITE ?
Triffaux, Jean-Marc ULg

Conference (2012, October 27)

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See detailCyberdépendance ? Réalité clinique ou invention psychopathologique ?
Lakaye, Ariane; Triffaux, Jean-Marc ULg

Article for general public (2012)

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