Search publications of the members of the Royal Belgian institute of natural Sciences
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Les monuments funéraires gallo-romains et l’emploi de la pierre dans la région Ouest de la civitas Treverorum.
- Abstract for an oral presentation / Groupe de recherche AcanthuM
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DNA barcoding and identification of terrestrial gastropods of parasitological concern for animals in Greece
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Provenance and technology of final Mesolithic and Neolithic pottery in the lower Scheldt valley (Belgium).
- XVIII Congres UISPP (International Union of the Prehistoric and Protohistoric Sciences), Adaptation et durabilité des sociétés préhistoriques et protohistoriques face aux variations climatiques. Paris, juin 2018. Session IV-3. Apport des approches technologiques de la céramique à l’anthropologie et à l’archéologie des sociétés pré- et protohistoriques – Contribution of the ceramic technological approaches to the anthropology and archeology of pre- et protohistoric societies.
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Etude archéométrique de la brique d’Ancien Régime à Bruxelles avant et après le bombardement par les troupes de Louis XIV en 1695 : distinction de la production briquetière locale des briques d'impportation.
- 21ème Colloque international du GMPCA, Archéométrie Rennes 1977 – 1997 – 20017 ; Rennes, 18-21 avril 2017. Abstract book 214p., p.175
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‘Not too white’: an investigation into the influence of the use of imported calcium carbonate-rich imported marls on 17 - 18th century Dutch tin-glaze tiles.
- Abstract et communication orale: Technart 2017. Non-destructive and microanalytical techniques in art and cultural heritage; International Conference, Bilbao (Portugal), May 2-6, 2017
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Environmental Impacts of Offshore Wind Farms in the Belgian Part of the North Sea: Assessing and Managing Effect Spheres of Influence
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First ever detections of bats made by an acoustic recorder installed on the nacelle of offshore wind turbines in the North Sea, In: Environmental Impacts of Offshore Wind Farms in the Belgian Part of the North Sea: Assessing and Managing Effect Spheres
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Elucidating the history of the European crow hybrid zone with paleogenomics. Preliminary Program of the Society for Molecular Biology and Evolution 2024
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Des crémations à la fin de la période romaine. L’exemple de la cité des Tongres et du cimetière de Fexhe-le-Haut-Clocher
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Comparing the transposon landscapes of a putative ancient asexual and a sexual non-marine ostracod (Crustacea, Arthropoda)
- Ostracods are microscopic, bi-valved crustaceans with the best fossil record of all living arthropods. Their fossil record, starting 400 million years ago, together with a high prevalence of parthenogenetic reproduction and putative ancient asexuality, make non-marine ostracods fascinating evolutionary model organisms. In the absence of high quality ostracod reference genomes, here we compare transposon landscapes between two Illumina genome assemblies from the putative ancient asexual Darwinula stevensoni and the fully sexual ostracod Notodromas monacha. Both assemblies have around 60,000 contigs, sizes of 360-380 Mb, more than 100X coverage and BUSCO scores of 93 and 94%, respectively. Because homology-based programs are not sensitive enough to detect families of transposable elements (TEs) in species missing from Repbase or Dfam, we used three different pipelines for de novo analyses: REPET, RepeatMasker2 (RM2) and EarlGrey (RM2-based, with automated curation). TE diversity between the two genomes differs substantially regardless which pipeline was used. The Illumina assembly of N. monacha is dominated by LTR retrotransposons (6.5%) with some DNA transposons (3.7%), whereas DNA (15.5%), LINE-like (5.9%) and rolling circle Helitron elements (1.5%) were most abundant in the assembly of D. stevensoni. Our results on the dominance of DNA (Tc/mar, hAT) and LINE-like (CR1, RTE) TEs in D. stevensoni parallel earlier findings from a partial genomic library, and differ from those of other asexuals. TE copies with a low number of nucleotide substitutions are only observed with REPET (“L” shape landscape) in both genomes. Although the presented results may underestimate TE abundance, they indicate pronounced differences of the transposon landscapes and diversity between these two ostracod species. Analysis of related species should determine whether the differences are correlated with the reproductive mode or are lineage specific.
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L’occupation humaine du Grognon à Namur au Mésolithique : résultats préliminaires des études archéobotaniques et archéozoologiques
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Implications of extensive addition of new sea star mitogenomes for sea star phylogenetics and evolution (Echinodermata: Asteroidea)
- Despite their ecological and evolutionary interests, the phylogeny of Asteroidea (sea stars) is still subject to debate at several taxonomic levels. In the present study, we assemble new mitochondrial genomes for 15 species, including three newly characterized families (Odontasteridae, Poraniidae, and Stichasteridae) and representing an important addition for two orders (Velatida and Spinulosida). By analysing them alongside the 31 previously available mitogenomes, we evaluate mitogenomic variation (mitogenome organization and phylogenetic relationships) within the class. Gene order and sizes were concordant with previous studies. However, an alternative initiation codon (ATT for NAD1) was found in two Pterasteridae species. Evolutionary patterns between orders provided some interesting insights (e.g. Spinulosida as the sister-group to the Valvatida + Paxillosida), but the most novel patterns were observed among families (e.g. close relationships of Stichasteridae and Paulasteriidae; close relationships of Odontasteridae and Poraniidae; Brisingidae and Freyellidae as sister-group to the Asteriidae, Paulasteridae, and Stichasteridae). Finally, we found Pterasteridae to be paraphyletic, which could lead to the incorporation of Myxasteridae within Pterasteridae. Altogether, this study confirms that mitogenomes provide valuable and cost-effective markers to complement evolutionary patterns derived from nuclear data.
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Sexual, Unisexual and Asexual Reproduction in Animals – Causes and Consequences
- Through fertilization of eggs and sperm, the most important consequence of sex is the generation of novel genetic combinations in each generation. Although evolutionary speaking, sex is costly, it is the most frequent reproductive mode in the animal kingdom, presenting an evolutionary paradox. Many hypotheses have been put forward to explain this puzzle. These can be divided into sex producing good genes for adaptations or sex being required to prevent the accumulation of bad genes. The causes and mechanisms of non-sexual reproductive modes in animals are almost as diverse as the animal world itself, and are described here in detail. Some asexual lineages have also developed novel mechanisms to substitute sex and mimic its evolutionary advantages.
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A process-based approach to assess the health of the marine environment
- Ocean sustainability entails the management of marine ecosystems and their services. Monitoring and evaluation of the health of the sea is challenged by the complexity of the marine environment, whose multitude and interconnected aspects, together with the lack of comprehensive models, make the understanding of its functioning a very arduous endeavour. Observations are costly and time-consuming. For this reason, a European joint action, named Science for Good Environmental Status, tested a new approach to monitor and evaluate effectively the state of health of the sea. This approach is based on the identification of driving physical processes that are present in the sea basins and directing the observation strategy to be designed on the basis of preliminary space–time information and patterns. The proof-of-concept of this approach has been implemented offshore of the Belgian coast in an attempt to achieve ecosystem assessments with targeted data collection methods requiring a reduced combination of variables. The proposed approach can impact monitoring activities implemented by those countries aiming to fulfil the requests of the European Marine Strategy Framework Directive. A map of EU marine areas to further test this process-based approach is also provided.
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Ostracod radiations
- Ostracods presently occur in almost all aquatic habitats, be they freshwater, brackish or marine, surface or groundwater, stagnant or flowing, in large lakes and small phytothelmata, in permanent or temporary pools, as well as in (semi-) terrestrial habitats. Some of these habitats are species-poor, other habitats harbour large numbers of species. Some of these species can be wide-spread (cosmopolitan and even ubiquitous), but others are endemic to a single lake or watershed. Why did speciation in certain ostracod lineages lead to large numbers of species in certain habitats, while other “ostracod lineage vs habitat type” combinations did not lead to such, often spectacular, morphological speciation events? A speciose lineage of ostracods which derived from a single ancestor is called a species flock. In ancient lakes such as Lake Baikal (Siberia, Russia), Lake Tanganyika and Lake Malawi (East Africa), several such ostracod species flocks exist side by side. These ancient lakes are excellent examples where ostracod radiations, including several species flocks, can be studied in situ, in the cradle in which they originated, namely in ostracod lineages such as Cyprideis s.l.and Cytherissa (Cytherideinae) (in Tanganyika and Baikal, respectively) , Gomphocythere (Timiriaseviinae) and Cypridopsis s.l., (Cypridopsinae) (in both Tanganyika and Malawi) to name only a few. Other examples of ostracod radiations are in the subfamily Candonidae in groundwaters in Pilbara (Australia), Texas (USA) and in Benin (West Africa). Several lineages in the family Cyprididae radiated in temporary water bodies on various continents, for example the genus Bennelongia (Cyprididae) in Australia, the genus Sclerocypris in the Megalocypridjnae in Africa and Cypretta and Strandesia in the southern Hemisphere (excluding Antarctica) as a whole. A special case are the species of the genus Elpidium (Timiriaseviinae) occurring in bromeliad phytothelmata in South and Central America. A new field of diversity discovery is in the identification of genetic species, which might not be identifiable based on the phenotype, aka “cryptic species”. Various intrinsic (pertaining to the specific biology) or extrinsic (habitat-related) factors can contribute to large speciation events resulting in ostracod radiations and species flocks. Yet, in some habitats where at least some of the extrinsic factors are present, no vast ostracod species flocks can be found. This is mostly due to historic events, such as in the African lakes Kivu and Turkana.
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Comparing the transposon landscapes of a putative ancient asexual and a sexual non-marine ostracod (Crustacea, Arthropoda)
- Ostracods are microscopic, bi-valved crustaceans with the best fossil record of all living arthropods. Their fossil record, starting 400 million years ago, together with a high prevalence of parthenogenetic reproduction and putative ancient asexuality, make non-marine ostracods fascinating evolutionary model organisms. In the absence of high quality ostracod reference genomes, we here compare transposon landscapes between two Illumina genome assemblies from the putative ancient asexual Darwinula stevensoni and the fully sexual ostracod Notodromas monacha. Both assemblies have around 60,000 contigs, sizes of 360-380 Mb, more than 100X coverage and BUSCO scores of 93 and 94%, respectively. Because homology-based programs are not sensitive enough to detect families of transposable elements (TEs) in species missing from Repbase or Dfam, we used three different pipelines for de novo analyses: REPET, RepeatMasker2 (RM2) and EarlGrey (RM2-based, with automated curation). TE diversity between the two genomes differs substantially regardless which pipeline was used. The Illumina assembly of N. monacha is dominated by LTR retrotransposons (6.5%) with some DNA transposons (3.7%), whereas DNA (15.5%), LINE-like (5.9%) and rolling circle Helitron elements (1.5%) were most abundant in the assembly of D. stevensoni. Our results on the dominance of DNA (Tc/mar, hAT) and LINE-like (CR1, RTE) TEs in D. stevensoni parallel earlier findings from a partial genomic library, and differ from those of other asexuals. TE copies with a low number of nucleotide substitutions are only observed with REPET (“L” shape landscape) in both genomes. Although the presented results may underestimate TE abundance, they indicate pronounced differences of the transposon landscapes and diversity between these two ostracod species. Analysis of related species should determine whether the differences are correlated with the reproductive mode or are lineage specific. We are currently curating TEs in an Oxford Nanopore draft assembly of D. stevensoni to further confirm our initial results.
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Ecology of ostracods inhabiting groundwater in Benin, West Africa, with potential use of stygobites as indicators for groundwater quality
- Ostracods are significant members of groundwater ecosystems, affected by both abiotic environmental factors and biotic interactions. This study investigates the factors influencing ostracod communities in groundwater from dug wells in several regions of Benin, West Africa, which experiences chronic anthropogenic disturbances such as nutrient enrichment from sewage and fertilizer infiltration. We evaluated the presence of ostracod species in 219 wells across seven catchment areas, examining 31 predictor variables, which include a variety of water quality parameters, hydrology as well as well closure, usage and type. The influence of these variables was analyzed using distance-based linear models and redundancy analysis. Our research identified 60 ostracod species, which we classified into two ecological groups: 1) 36 stygobitic species from the family Candonidae, which represent an endemic evolutionary radiation, and 2) 24 non-stygobitic species, mostly from the family Cyprididae. Through our analysis, we identified several key factors influencing ostracod community structure, with consistent patterns observed at both species and genus levels. The primary predictors, aside from well descriptors, included water chemical and physical properties, such as electrical conductivity, pH, temperature, and bicarbonate concentration, along with NO2- concentration, a factor not previously demonstrated to be crucial for ostracod assemblages. Elevated nitrite levels in groundwater were found to significantly affect the distribution of stygobites and non-stygobites. Stygobites were notably less frequent in environments with higher NO2- concentrations, likely due to their greater vulnerability to periodic or chronic anthropogenic disturbances compared to non-stygobites. Therefore, we suggest that stygobitic ostracod species, identifiable even at the genus level, have a potential as reliable indicators of groundwater quality in the tropical regions of western Africa.
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Accounting for interspecies and intraspecies variation in swimming performance for fish passage solutions
- Across the globe, there are millions of in-stream structures that fragment the world'’s river networks, acting as barriers that can impede the movements of fish. Designing effective solutions to accommodate fish communities requires information about the swimming abilities and behaviours of all species. This should account for different swimming modes, abilities, behaviours, and niches. We investigated the swimming speeds of nine migratory New Zealand species to assess both inter- and intraspecies variation. We then calculated maximum traversable speeds for culverts of a given length, based on the endurance abilities of our lowest performing species (Galaxias maculatus). Our findings reveal significant inter- and intraspecies variation in swimming speeds. Among the species studied, Galaxias brevipinnis, Galaxias argenteus, and Galaxias postvectis were the strongest swimmers. In contrast, Galaxias maculatus was one of the weakest swimmers. Body length positively correlated with Umax indicating that fish passage barriers select against the weakest swimming species, as well as smaller individuals within a species. Maximum water speeds in a culvert must be lower than 0.3 m s−-1, the previously assumed standard rule-of-thumb for New Zealand, to provide adequate passage for a high proportion of a weak-swimming indicator species (Galaxias maculatus). Synthesis and applications: . Previous maximum traversable water speeds for fish passage designs have been based on average swimming ability, but this approach only enables fish that are better than the average swimmers of their species to overcome barriers. This study highlights the importance of evidence-based designs for successful fish passage solutions to account for the ability of all fish. By considering differences between and within species, rather than assuming a “‘one-size-fits-all” ’ approach we can develop more effective passage solutions that better preserve fish communities.
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A New Species of Elpidium (Crustacea, Ostracoda) from Bromeliad and Non-bromeliad Phytotelmata in the Northeast of Argentina
- A new species of the ostracod genus Elpidium (Timiriaseviinae), a group almost exclusively known from Neotropical bromeliad phytotelmata, is here described and illustrated from the northeast of Argentina. Elpidium chacoense n. sp. represents the first record of the genus in this country and brings the total of described Elpidium species to 19. In view of the recently increased knowledge on the distribution of the species in this Neotropical genus, we discuss potential drivers of speciation that might have led to the high (endemic) diversity of the group: allopatry in bromeliad islands, sexual selection and putative co-evolution between ostracod and bromeliad species. We also point out the biogeographical relevance of the present records, which are amongst the most southern of the genus. Finally, also the fact that species of Elpidium can now also be found in non-bromeliad phytotelmata is of relevance.
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Comparing the transposon landscapes of a putative ancient asexual and a sexual non-marine ostracod (Crustacea, Arthropoda)
- Ostracods are microscopic, bi-valved crustaceans with the best fossil record of all living arthropods. Their fossil record, starting 400 million years ago, together with a high prevalence of parthenogenetic reproduction and putative ancient asexuality, make non-marine ostracods fascinating evolutionary model organisms. In the absence of high quality ostracod reference genomes, we here compare transposon landscapes between two Illumina genome assemblies from the putative ancient asexual Darwinula stevensoni and the fully sexual ostracod Notodromas monacha. Both assemblies have around 60,000 contigs, sizes of 360-380 Mb, more than 100X coverage and BUSCO scores of 93 and 94%, respectively. Because homology-based programs are not sensitive enough to detect families of transposable elements (TEs) in species missing from Repbase or Dfam, we used three different pipelines for de novo analyses: REPET, RepeatMasker2 (RM2) and EarlGrey (RM2-based, with automated curation). TE diversity between the two genomes differs substantially regardless which pipeline was used. The Illumina assembly of N. monacha is dominated by LTR retrotransposons (6.5%) with some DNA transposons (3.7%), whereas DNA (15.5%), LINE-like (5.9%) and rolling circle Helitron elements (1.5%) were most abundant in the assembly of D. stevensoni. Our results on the dominance of DNA (Tc/mar, hAT) and LINE-like (CR1, RTE) TEs in D. stevensoni parallel earlier findings from a partial genomic library, and differ from those of other asexuals. TE copies with a low number of nucleotide substitutions are only observed with REPET (“L” shape landscape) in both genomes. Although the presented results may underestimate TE abundance, they indicate pronounced differences of the transposon landscapes and diversity between these two ostracod species. Analysis of related species should determine whether the differences are correlated with the reproductive mode or are lineage specific. We are currently curating TEs in an Oxford Nanopore draft assembly of D. stevensoni to further confirm our initial results.
