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Peer Reviewed
See detailDiversity and pathogenicity of Pseudomonas cichorii isolates causing midrib rot on lettuce
Pauwelyn, E.; Ongena, Marc ULg; Cottyn, B. et al

Conference (2010)

Detailed reference viewed: 12 (0 ULg)
See detailThe diversity and tolerance to osmotic stress of East Antarctic filamentous Cyanobacteria
Obbels, Dagmar; Verleyen, Elie; Tytgat, Bjorn et al

Poster (2013, July)

Filamentous cyanobacteria are keystone species in Antarctic lake ecosystems; they are the basis of the simple foodwebs, play a crucial role in biogeochemical cycling and form the structure of benthic ... [more ▼]

Filamentous cyanobacteria are keystone species in Antarctic lake ecosystems; they are the basis of the simple foodwebs, play a crucial role in biogeochemical cycling and form the structure of benthic microbial mats which act as habitats for other prokaryotic and (micro-eukaryotic biota. Despite this, little is known about their diversity, adaptation and survival strategies in the extreme Antarctic conditions. We studied the uncultivated prokaryotic diversity using a 454 metagenomic analysis at the 16S rRNA level (V1-V3 region) in Continental Antarctic lakes situated along a conductivity gradient (0.014-142.02 mS/cm). The quality and length of the amplicons was analyzed with a custom-made Mothur pipeline and the resulting sequences were mapped against the Greengenes database, which includes CyanoDB. Almost 27% of the sequences could be assigned to the phylum of the cyanobacteria. The most abundant cyanobacteria in the dataset belonged to the genera Microcoleus, Leptolyngbya, Pseudanabaena, Nodularia and Phormidum. Some 16S rRNA types (at the 97% similarity level), such as sequences related to Leptolynbya antarctica, were present in both freshwater and hypersaline lakes. In order to further investigate this distribution, we isolated filaments of Leptolyngbya from seven lakes with conductivities ranging between 26.8 mS/cm and 0.038 mS/cm. The complete 16S rRNA and ITS genes of the isolates were subsequently sequenced. We found several 16S types related to different lineages of filamentous cyanobacteria in the seven lakes that were supported by ITS data. Two 16S types, belonging to a Leptolyngbya antarctica and Leptolyngbya sp., were each present in two different freshwater lakes. Two different 16S types, both belonging to Leptolynbya antarctica were present in a freshwater and hypersaline lake, which indicates a high ‘intraspecific’ molecular diversity. In order to better understand the adaptation and/or wide tolerance to osmotic stress, we are currently performing ecophysiological experiments with these isolates aimed at assessing the potential local adaptation of these strains to conductivity and desiccation. [less ▲]

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See detailDiversity dynamics of non-lycopsid lycophytes
Cascales - Miñana, Borja ULg; Meyer-Berthaud, Brigitte

in Cascales - Miñana, Borja; Villanueva-Amadoz, Uxue; Diez, José B. (Eds.) Proceedings of the II Agora Paleobotanica Meeting (Abstract book) (2013, July)

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See detailDiversity dynamics of Zosterophyllopsida
Cascales - Miñana, Borja ULg; Meyer-Berthaud, Brigitte

in Lethaia (2014), 47(2), 205-215

The Zosterophyllopsida were major contributors to the diversification of early land plants. We present the first detailed analysis of the diversity dynamics of these plants from an updated database of all ... [more ▼]

The Zosterophyllopsida were major contributors to the diversification of early land plants. We present the first detailed analysis of the diversity dynamics of these plants from an updated database of all currently recognized zosterophyllopsid species. A set of quantitative methods classically used in palaeodiversity studies was applied to two data sets. The first one, 'Zosterophyllopsida sensu stricto', corresponds to the clade identified by Hao & Xue (The Early Devonian Posongchong Flora of Yunnan. (2013), Science Press). In the second, called 'Zosterophyllopsida sensu lato', barinophytalean-type plants and taxa for which zosterophyllopsid affinities are suspected are added. The number of localities is used to explore sampling bias. Results show that sampling effect is minimal for the Early Devonian. For this time interval, both data sets record consistent patterns of changes suggesting that, whatever their affinities, all taxa included in the Zosterophyllopsida sensu lato show similar evolutionary trends. The diversity dynamics of zosterophyllopsids are characterized by a radiation during the Lochkovian, maximal values in the Pragian and a decline starting in the Emsian. The proportion of zosterophyllalean taxa with terminal sporangia is high until the Late Lochkovian when gosslingialean taxa without terminal sporangia evolved. During the Middle and Late Devonian, when diversity patterns are strongly affected by sampling, zosterophyllopsid diversity is low and characterized by a high proportion of barinophytacean and gosslingialean taxa, the latter becoming extinct in the Early Frasnian. © 2013 The Lethaia Foundation. [less ▲]

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See detailDiversity dynamics of Zosterophyllopsida (Lycophyta, Middle Paleozoic)
Cascales - Miñana, Borja ULg; Meyer-Berthaud, Brigitte

Conference (2013, September)

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See detailDiversity in the City
Martiniello, Marco ULg; Piquard, Bernadette

Book published by University of Deusto (2002)

Detailed reference viewed: 14 (1 ULg)
See detailDiversity in the City
Piquard, B.; Martiniello, Marco ULg

Book published by University of Deusto, Humanitatianet (2002)

Detailed reference viewed: 11 (0 ULg)
Peer Reviewed
See detailDiversity in the sound production mechanism in Ophidiiformes
Parmentier, Eric ULg; Mann, David; Kever, Loïc ULg et al

Conference (2010)

Detailed reference viewed: 17 (3 ULg)
Peer Reviewed
See detailDiversity Management in Belgium
Cornet, Annie ULg; Zanoni

Conference (2010)

Detailed reference viewed: 33 (5 ULg)
Peer Reviewed
See detailDiversity management status in morocco. an exploratory stydu
El Abboubi, Manal ULg; El Kandoussi, Fatima

Conference (2009, July 16)

The purpose of this article is to explore diversity management specificities in arab countries, especially in Morocco (North Africa). We analyse organisational initiatives, managers’ perception and the ... [more ▼]

The purpose of this article is to explore diversity management specificities in arab countries, especially in Morocco (North Africa). We analyse organisational initiatives, managers’ perception and the way they mainstream diversity tools in their management. The Moroccan industry is based on two major sectors: agriculture food and textile. Those two activities represent more than 50% of the PIB, 70% of the national employment and 75% of exportations. We focus our study on those two sectors which are a pillar of the morrocan economy. Our sample consist of 30 questionnaire sent to companies that have more than 50 employees. We received 16 answers. We questioned CEOs, managers, middle managers and employees. The main contribution of the research is that moroccan leaders are aware of their responsibilities to implement and carry out diversity projects. The main topics mentioned concerns equality and gender. However, they have no skills or power to ensure that responsibilities fully. Diversity management is not included in the strategy. It remains a minor task operated mainly by the human resource department. Morrocan managers need more specific trainings and a global governmental policy to guide their actions. Employees are not well informed about their rights. Moreover, Morocco will open a free exchange zone in 2010. This is an opportunity for many international companies to invest in the country. Most of them are from Europe and USA. They are well informed about diversity management, especially gender issues. This represents a threat for Moroccan companies who feel the urgency to develop a national framework for diversity management. Our research is still under study. We are collecting more data and we aim to integrate some extra stakeholders in the sample. Mainly the government and the local communities. The fact that we interviewed only managers gives us a limited view of the diversity management status in Morocco. [less ▲]

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See detailDiversity of Bacterial Communities in a Profile of a Winter Wheat Field: Known and Unknown Members
Stroobants, Aurore ULg; Degrune, Florine ULg; Olivier, Claire et al

in Microbial Ecology (2014)

In soils, bacteria are very abundant and diverse. They are involved in various agro-ecosystem processes such as the nitrogen cycle, organic matter degradation, and soil formation. Yet, little is known ... [more ▼]

In soils, bacteria are very abundant and diverse. They are involved in various agro-ecosystem processes such as the nitrogen cycle, organic matter degradation, and soil formation. Yet, little is known about the distribution and composition of bacterial communities through the soil profile, particularly in agricultural soils, as most studies have focused only on topsoils or forest and grassland soils. In the present work, we have used bar-coded pyrosequencing analysis of the V3 region of the 16S rRNA gene to analyze bacterial diversity in a profile (depths 10, 25, and 45 cm) of a well-characterized field of winter wheat. Taxonomic assignment was carried out with the Ribosomal Database Project (RDP) Classifier program with three bootstrap scores: a main run at 0.80, a confirmation run at 0.99, and a run at 0 to gain information on the unknown bacteria. Our results show that biomass and bacterial quantity and diversity decreased greatly with depth. Depth also had an impact, in terms of relative sequence abundance, on 81 % of the most represented taxonomic ranks, notably the ranks Proteobacteria, Bacteroidetes, Actinobacteridae, and Acidobacteria. Bacterial community composition differed more strongly between the topsoil (10 and 25 cm) and subsoil (45 cm) than between levels in the topsoil, mainly because of shifts in the carbon, nitrogen, and potassium contents. The subsoil also contained more unknown bacteria, 53.96 % on the average, than did the topsoil, with 42.06 % at 10 cm and 45.59 % at 25 cm. Most of these unknown bacteria seem to belong to Deltaproteobacteria, Actinobacteria, Rhizobiales, and Acidobacteria. [less ▲]

Detailed reference viewed: 92 (25 ULg)
See detailThe diversity of Clostridial hydrogenases and biohydrogen production
Calusinska, Magdalena ULg; Savichtcheva, Olga; Masset, Julien ULg et al

Poster (2009, June 18)

Molecular hydrogen is a key intermediate in metabolomic interactions of a wide range of microorganisms. Hydrogen is also regarded as a key component in future energy systems as it is a sustainable, clean ... [more ▼]

Molecular hydrogen is a key intermediate in metabolomic interactions of a wide range of microorganisms. Hydrogen is also regarded as a key component in future energy systems as it is a sustainable, clean, and transportable energy carrier. Some microorganisms can produce hydrogen during a reversible reduction of protons to dihydrogen, a reaction which is catalyzed by hydrogenases [1]. Hydrogenases belong to an iron – sulphur protein family, that contains active sites consisting of inorganic sulfide and iron atoms bound to the polypeptide chain. On the basis of their bimetallocenter composition hydrogenases are divided into three main groups, phylogenetically not related: [NiFe] hydrogenases, [Fe] only hydrogenases and ‘metal – free hydrogenases’ which were described in methanogenic Archaea only. [NiFe] hydrogenases, composed of at least two subunits are well characterized and widely distributed between Archaea and Bacteria but only a few representatives of Clostridium possess this type of enzyme. On the other hand, [Fe] only hydrogenases, being usually monomeric enzymes and restricted to Bacteria and a few eukaryotic species are far less described. These proteins, being omnipresent catalysts of many biological reactions, are especially abundant in Clostridia. The physiological function of Clostridial [Fe] only hydrogenases is to dispose under the form of hydrogen, of the excess of reducing power generated during the fermentation of carbohydrates. The unusual diversity of forms of [Fe] only hydrogenases within Clostridia seems to support the central role of this enzyme in cell metabolism and to facilitate the quick adaptation of the host to changing environmental conditions. Moreover, the presence of multiple putative operons encoding for multisubunit [Fe] only hydrogenases in the genomes of sequenced Clostridium spp. is highlighting the need to study the new, not yet described function of these ostensibly simple proteins. In this project, we have focused our effort on the molecular characterization of key enzymes involved in the process of biohydrogen production with a special interest in Clostridium species. By applying molecular techniques on samples from different kinds of bioreactors, we want to select highly productive species in terms of hydrogen generation. We also believe that gene expression profiling will provide new data on the possible function and activity of different hydrogenases involved in the process. The better understanding of hydrogen metabolism is essential for its sustainable production. [less ▲]

Detailed reference viewed: 36 (5 ULg)
See detailThe diversity of clostridial hydrogenases revealed by genome sequencing projects
Calusinska, Magdalena ULg; Wilmotte, Annick ULg; Joris, Bernard ULg

Poster (2009, December 15)

Molecular hydrogen is a key intermediate in metabolomic interactions of a wide range of microorganisms. Hydrogen is also regarded as a key component in future energy systems as it is a sustainable, clean ... [more ▼]

Molecular hydrogen is a key intermediate in metabolomic interactions of a wide range of microorganisms. Hydrogen is also regarded as a key component in future energy systems as it is a sustainable, clean, and transportable energy carrier. Some microorganisms can produce hydrogen during a reversible reduction of protons to dihydrogen, a reaction which is catalyzed by the enzyme hydrogenases. On the basis of their bimetallocenter composition, hydrogenases are divided into three main groups, phylogenetically not related: [NiFe] hydrogenases, [Fe] only hydrogenases and FeS cluster free hydrogenases. The latter were described in methanogenic Archaea only. [NiFe] hydrogenases, composed of at least two subunits are well characterized and widely distributed between Archaea and Bacteria. However, only a few representatives of Clostridium sp. possess this type of enzyme. On the other hand, much less is known about the [Fe] only hydrogenases, that are usually monomeric enzymes and restricted to Bacteria and a few eukaryotic species. Genome sequencing projects gave a completely new insight into the diversity of forms of putative [Fe] only hydrogenases within the genus Clostridium. With the use of bioinformatic tools, we have described the unusual modularity of forms of these enzymes, from monomeric to tetrameric with a different number of accessory domains reacting with diverse redox partners. This fact seems to support the central role of hydrogenases in cell metabolism and quick adaptation of the host to changing environmental conditions. Moreover, the presence of multiple putative operons encoding for multisubunit [FeFe] hydrogenases is highlighting the fact that hydrogen metabolism is very complex in the Clostridium genus. [less ▲]

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See detailDiversity of Clostridium difficile isolates from humans and animals
Rodriguez Diaz, Cristina ULg; Taminiau, Bernard ULg; Korsak Koulagenko, Nicolas ULg et al

Scientific conference (2014, October 17)

Clostridium difficile is an important cause of infectious diarrhea in hospitals. The major risk factors for the development of nosocomial C. difficile associated disease include antibiotic therapy and ... [more ▼]

Clostridium difficile is an important cause of infectious diarrhea in hospitals. The major risk factors for the development of nosocomial C. difficile associated disease include antibiotic therapy and increasing age. In animals, as pigs, calves and horses, C. difficile also seems to be an important cause of enteric disease. The main objective of this study was to characterize and compare animal and human C. difficile strains with respect to the PCR-ribotype and the antibiotic resistance. Multilocus sequence typing (MLST) and multiple-Locus Variable number tandem repeat analysis (MLVA) were performed in order to study clonal relationships of the isolates. Human C. difficile isolates were obtained from care home residents and hospitalized patients. Animal isolates were collected from stool samples and carcasses of pigs and cattle at slaughter. An identification of the strains was performed by PCR-ribotyping. Further characterization was performed by antibiotic resistance, MLST and MLVA analysis. A neighbourd-joining phylogenetic three was constructed in order to determine the correlation between human and food isolates. A great variety of PCR ribotypes was found among the animal isolates, including PCR ribotypes 078 and 014. The most prevalent PCR-ribotypes in the nursing home were PCR-ribotypes 027 and 020. A high resistance to moxifloxacin, erythromycin, gentamicin and clindamycin was detected for some of the strains. Phylogenetic analysis showed that human and animal isolates with the same PCR-ribotype cluster in the same lineage, suggesting a potential risk of interspecies transmission. [less ▲]

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See detailDiversity of cucurbit species cultivated in Côte d'Ivoire for Edible Seeds
Zoro Bi, I.; Koffi; Dje, Y. et al

in Cucurbit Genetics Cooperative, Report 2005 (2005), (28-29), 84-90

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See detailDiversity of culturable bacteria including Pantoea in wild mosquito Aedes albopictus
Claire Valiente, Claire; Tran, Florence Hélène; Raharimalala, Fara Nantenaina ULg et al

in BMC Microbiology (2013), 13

Background: The microbiota has been shown to play an important role in the biology of insects. In recent decades, significant efforts have been made to better understand the diversity of symbiotic ... [more ▼]

Background: The microbiota has been shown to play an important role in the biology of insects. In recent decades, significant efforts have been made to better understand the diversity of symbiotic bacteria associated with mosquitoes and assess their influence on pathogen transmission. Here, we report the bacterial composition found in field-caught Aedes albopictus populations by using culture-dependent methods. Results: A total of 104 mosquito imagos (56 males and 48 females) were caught from four contrasting biotopes of Madagascar and their bacterial contents were screened by plating whole body homogenates on three different culture media. From 281 bacterial colony types obtained, amplified ribosomal DNA restriction analysis (ARDRA) showed they had 40 distinct ribotypes. Sequencing and BLAST analysis of the 16S rDNA genes responsible for each representative profile made it possible to identify 27 genera distributed in three major phyla. In female mosquitoes, bacterial isolates were mostly Proteobacteria (51.3%) followed by Firmicutes (30.3%) and Actinobacteria (18.4%). Conversely, Actinobacteria was the most abundant phylum in male mosquitoes (48%) followed by Proteobacteria (30.6%) and Firmicutes (20.4%). The relative abundance and composition of isolates also varied between sampling sites, ranging from 3 distinct families in Ankazobe to 8 in Tsimbazaza Park, and Toamasina and Ambohidratrimo. Pantoea was the most common genus in both females and males from all sampling sites, except for Ambohidratrimo. No differences in genome size were found between Pantoea isolates from mosquitoes and reference strains in pulse field gel electrophoresis. However, according to the numbers and sizes of plasmids, mosquito isolates clustered into three different groups with other strains isolated from insects but distinct from isolates from the environment. Conclusions: The recent upsurge in research into the functional role of the insect microbiota prompts the interest to better explore the role some bacteria detected here may have in the mosquito biology. Future studies of culturable bacteria might decipher whether they have a biological role in the invasiveness of Ae. albopictus. As a possible candidate for paratransgenesis, the predominant genus Pantoea will be characterized to better understand its genetic contents and any possible influence it may have on vector competence of Ae. albopictus. [less ▲]

Detailed reference viewed: 22 (6 ULg)
See detailDiversity of Ecosystems and Coastal Ocean CO2 Fluxes
Borges, Alberto ULg

Conference (2005)

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See detailDiversity of forensic rove beetles (Coleoptera, Staphylinidae) associated with decaying pig carcass in a forest biotope
Dekeirsschieter, Jessica ULg; Frederickx, Christine ULg; Verheggen, François ULg et al

in Journal of Forensic Sciences (2013)

Most forensic studies are focused on Diptera pattern colonization while neglecting Coleoptera succession. So far, little information is available on the postmortem colonization by beetles and the ... [more ▼]

Most forensic studies are focused on Diptera pattern colonization while neglecting Coleoptera succession. So far, little information is available on the postmortem colonization by beetles and the decomposition process they initiate under temperate biogeoclimatic countries. These beetles have however been referred to as being part of the entomofaunal colonization of a dead body. Forensic entomologists need increased databases detailing the distribution, ecology and phenology of necrophagous insects, including staphylinids (Coleoptera, Staphylinidae). While pig carcasses are commonly used in forensic entomology studies to surrogate human decomposition and to investigate the entomofaunal succession, very few works have been conducted in Europe on large carcasses. Our work reports the monitoring of the presence of adult rove beetles (Coleoptera, Staphylinidae) on decaying pig carcasses in a forest biotope during four seasons (spring, summer, fall and winter). A total of 23 genera comprising 60 species of rove beetles were collected from pig carcasses. [less ▲]

Detailed reference viewed: 234 (24 ULg)