Browsing
     by title


0-9 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

or enter first few letters:   
OK
See detailCyanoacrylate biopsy for cytologic evaluation of the epidermis
ARRESE ESTRADA, Jorge ULg; QUATRESOOZ, Pascale ULg; PIERARD-FRANCHIMONT, Claudine ULg et al

in Hand-book of non-invasive methods and the skin (2005)

Detailed reference viewed: 13 (4 ULg)
Full Text
Peer Reviewed
See detailCyanoacrylate skin surface / follicular stripping.
PIERARD, Gérald ULg; Franchimont, Claudine ULg; Delvenne, Philippe ULg et al

in Berardesca, Enzo; Wilhelm, KP; Maibach, H.I. (Eds.) Non invasive diagnostic techniques in clinical dermatology. (2014)

Detailed reference viewed: 23 (10 ULg)
See detailCyanoacrylate skin surface strippings
PIERARD-FRANCHIMONT, Claudine ULg; ARRESE ESTRADA, Jorge ULg; QUATRESOOZ, Pascale ULg et al

in Textbook of aging skin (2010)

Detailed reference viewed: 9 (6 ULg)
Full Text
Peer Reviewed
See detailCyanobacteria from benthic mats of Antarctic lakes as a source of new bioactivities
Biondi, Natascia; Tredici, Mario; Taton, Arnaud et al

in Journal of Applied Microbiology (2008), 105(1), 105-115

Aims: To exploit the cyanobacterial diversity of microbial mats growing in the benthic environment of Antarctic lakes for the discovery of novel antibiotic and antitumour activities. Methods and results ... [more ▼]

Aims: To exploit the cyanobacterial diversity of microbial mats growing in the benthic environment of Antarctic lakes for the discovery of novel antibiotic and antitumour activities. Methods and results: In all, 51 Antarctic cyanobacteria isolated from benthic mats were cultivated in the laboratory by optimizing temperature, irradiance and mixing. Productivity was generally very low (£60 mg l)1 d)1) with growth rates (l) in the range of 0Æ02–0Æ44 d)1. Growth rates were limited by photosensitivity, sensitivity to air bubbling, polysaccharide production or cell aggregation. Despite this, 126 extracts were prepared from 48 strains and screened for antimicrobial and cytotoxic activities. Seventeen cyanobacteria showed antimicrobial activity (against the Gram-positive Staphylococcus aureus, the filamentous fungus Aspergillus fumigatus or the yeast Cryptococcus neoformans), and 25 were cytotoxic. The bioactivities were not in accordance with the phylogenetic grouping, but rather strain-specific. One active strain was cultivated in a 10-l photobioreactor. Conclusions: Isolation and mass cultivation of Antarctic cyanobacteria and LCMS (liquid chromatography ⁄ mass spectrometry) fractionation of extracts from a subset of those strains (hits) that exhibited relatively potent antibacterial and ⁄ or antifungal activities, evidenced a chemical novelty worthy of further investigation. Significance and impact of the study: Development of isolation, cultivation and screening methods for Antarctic cyanobacteria has led to the discovery of strains endowed with interesting antimicrobial and antitumour activities. [less ▲]

Detailed reference viewed: 44 (7 ULg)
Full Text
Peer Reviewed
See detailCyanobacteria immobilised in porous silica gels: Exploring biocompatible synthesis routes for the development of photobioreactors
Léonard, Alexandre ULg; Rooke, J. C.; Meunier, C. F. et al

in Energy and Environmental Science (2010), 3(3), 370-377

With the aim of designing photobioreactors (PBR) based on a smart exploitation of microalgae for the production of biofuels and metabolites of interest, this paper describes a novel approach where ... [more ▼]

With the aim of designing photobioreactors (PBR) based on a smart exploitation of microalgae for the production of biofuels and metabolites of interest, this paper describes a novel approach where cyanobacteria are entrapped within highly porous silica matrices. With this concept, it would be possible to work with a constant population of organisms for a continuous (and increased) photoproduction of metabolites, in contrast to "one-shot" uses of liquid cultures. Different hybrid materials based on porous silica gels are described with a special emphasis on finding the most appropriate immobilisation conditions for prolonged cell survival. It is found that an aqueous route based on acid-exchanged sodium silicate combined with the use of silica nanoparticles as a gel-strengthening species shows the best results with a high primary production rate post immobilisation and a preservation of the photosynthetic pigments of up to 35 weeks. Oxygen production, though very low, could be evidenced up to 17 weeks after entrapment, demonstrating the suitability of using porous silica matrices in PBR design. © 2010 The Royal Society of Chemistry. [less ▲]

Detailed reference viewed: 7 (2 ULg)
Full Text
See detailCyanobacteria in cold environments
Zakhia, Frederic; Jungblut, Anne-Dorothee; Taton, Arnaud et al

in Margesin, Rosi; Schinner, Frederic; Marx, Jean-Claude (Eds.) et al 'Psychrophiles: from Biodiversity to Biotechnology (2007)

Cyanobacteria evolved under the harsh conditions of the Precambrian and their modern representatives retain a remarkable ability to adapt to and survive within extreme conditions. They dominate ... [more ▼]

Cyanobacteria evolved under the harsh conditions of the Precambrian and their modern representatives retain a remarkable ability to adapt to and survive within extreme conditions. They dominate terrestrial and freshwater cold ecosystems of the Arctic, Antarctic and alpine regions, even though they do not seem to be specifically adapted to optimal growth at low temperatures. They play a major ecological role as they often are primary colonisers of substrates and major primary producers in these ecosystems. The application of molecular tools in combination with classic morphological techniques has begun to provide new insights into the real diversity of cyanobacteria and their biogeographical distribution in cold environments. Our survey of recent studies suggests complex distributional patterns of cyanobacteria, with cosmopolitan, endemic, and habitat-specific genotypes. This ongoing research will help to identify specific geographical areas that have unique microbial communities. However, many more studies are needed to unravel the enormous diversity of cyanobacteria and to better define their biogeographical patterns in cold environments. This is an urgent task in view of the climatic changes that will undoubtedly alter the structure and functioning of microbial communities in polar and alpine ecosystems. [less ▲]

Detailed reference viewed: 52 (1 ULg)
Full Text
Peer Reviewed
See detailCyanobacteria in microbial mats of Antarctic lakes (East Antarctica) - A microscopical approach
Taton, Arnaud; Hoffmann, Lucien; Wilmotte, Annick ULg

in Algological Studies (2008), 168

The cyanobacterial diversity in microbial mats of 56 lakes located in the Larsemann Hills and Bølingen Islands (East Antarctica) was studied by light microscopy. Thirty taxa belonging to 13 genera of ... [more ▼]

The cyanobacterial diversity in microbial mats of 56 lakes located in the Larsemann Hills and Bølingen Islands (East Antarctica) was studied by light microscopy. Thirty taxa belonging to 13 genera of Chroococcales, Oscillatoriales and Nostocales were described. Photomicrographs of the different taxa are provided and their taxonomical assignment as well as their ecology and distribution are discussed. In addition, a semi-quantitative estimation of the abundance of the different morphotypes in the samples was realized and correlated with the mat physiognomy. [less ▲]

Detailed reference viewed: 87 (6 ULg)
Full Text
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)

Detailed reference viewed: 5 (0 ULg)
Full Text
Peer Reviewed
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

Detailed reference viewed: 27 (6 ULg)
Full Text
Peer Reviewed
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 ▲]

Detailed reference viewed: 54 (6 ULg)
Full Text
See detailCyanobacterial diversity in the Transantarctic Mountains (Antarctica).
Fernandez Carazo, Rafael ULg; Hodgson, Dominic; Wilmotte, Annick

Poster (2008, August 31)

Detailed reference viewed: 5 (0 ULg)
Peer Reviewed
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

Detailed reference viewed: 17 (4 ULg)
Full Text
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 ▲]

Detailed reference viewed: 105 (5 ULg)
Full Text
Peer Reviewed
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 ▲]

Detailed reference viewed: 66 (1 ULg)
Peer Reviewed
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

Detailed reference viewed: 7 (1 ULg)
Full Text
See detailCybearctivistes et société civile. Les ambigüités de la révolution tunisienne
Lecomte, Romain ULg

Article for general public (2011)

Detailed reference viewed: 95 (2 ULg)
Full Text
See detailLes cyber-taureaux des vétérinaires liégeois
Durand, Pascal ULg

Article for general public (1996)

Detailed reference viewed: 4 (0 ULg)
Full Text
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 ▲]

Detailed reference viewed: 150 (2 ULg)