557 research outputs found
Europe counts marine life
Over 500 marine scientists are working together within the framework of MarBEF - a European network of excellence, which started in March 2004. Of all the seas, the European seas are among the most studied in the world. By bringing this expertise and knowledge together, MarBEF aims at a better understanding of long-term and large-scale distribution patterns and functionalities of biodiversity across marine ecosystems. To inventory this wealth of marine life, the European Register of Marine Species (ERMS), at this moment containing nearly 30,000 species names, is adopted and will serve as the reference list and taxonomic backbone within MarBEF. ERMS has been put into a relational database and will be maintained and regularly updated online by a consortium of taxonomic experts. The taxonomic register will be supplemented with biogeographic, ecological and socio-economic information, together with species illustrations, original descriptions and vernacular names. When available, links will be provided with other online species information systems. EurOBIS, the European node of the Ocean biogeographic Information System, is a distributed system that integrates individual datasets on biogeographic information into one large consolidated database and provides the end-user with a fully searchable geographic interface. EurOBIS already captures and freely communicates over 350,000 distribution data from 14,000 species, online. When combining these data with biological, physical, chemical and geologic data, our understanding of the ecosystem will greatly improve, resulting in better ecosystem-based management plans. The Flanders Marine Institute is taking a leading role in these major European data integrating projects within MarBEF and has recently developed online tools for ERMS and EurOBIS (http://www.marbef.org/data)
A Noncoherent Space-Time Code from Quantum Error Correction
In this work, we develop a space-time block code for noncoherent
communication using techniques from the field of quantum error correction. We
decompose the multiple-input multiple-output (MIMO) channel into operators from
quantum mechanics, and design a non-coherent space time code using the quantum
stabilizer formalism. We derive an optimal decoder, and analyze the former
through a quantum mechanical lens. We compare our approach to a comparable
coherent approach and a noncoherent differential approach, achieving comparable
or better performance.Comment: 6 pages, one figure, accepted at the 53rd annual Conference on
Information Sciences and System
FAIRMODE: A FORUM FOR AIR QUALITY MODELLING IN EUROPE
FAIRMODE (Forum for AIR quality MODelling in Europe) is an air quality modelling network that was established as a
joint initiative of the European Environment Agency (EEA) and European Commission’s Joint Research Centre (JRC). In a
common effort EEA and JRC aim at responding to the requirements of the new Air Quality Directive, with particular focus on the
introduction of modelling as a necessary tool for air quality assessment and air quality management. The main aim of the modelling
network is to bring together air quality modellers and model users in order to promote and support harmonised use of modelling for
the assessment of air quality by EU and EEA member countries. The network will thus encourage synergy – at a local, national and
European level - through the development and implementation of a common infrastructure based on best practices for reporting and
storing information relevant to air quality modelling. A major objective of the FAIRMODE initiative is to provide guidance to
present and future air quality model users in EEA’s EIONET partnership network. FAIRMODE also aims to enhance awareness of
model usefulness, reliability and accuracy through model validation and intercomparison exercises at a national or European level.
The JRC has taken on a leading role in the co-ordination of the latter activities gaining from its experience in leading the
“Eurodelta” and “CityDelta” intercomparison exercises.
A centralised web portal has been created in support of FAIRMODE, which is currently being used for internal communication
purposes of the network participants, but will also provide the means for exchange of relevant material and experiences between all
interested modellers and model users. The initial activities of the network will be organised by two main Work Groups, focusing on
the preparation of a Guidance Document for model use and on model QA/QC procedures (input data, other uncertainties)
respectively. The progress of the preparation of these documents as well as of the rest of the regular activities of the network will be
reviewed and discussed within the frame of annual Plenary meetings and Steering Committee meetings
How and why DNA barcodes underestimate the diversity of microbial eukaryotes
Background: Because many picoplanktonic eukaryotic species cannot currently be maintained in culture, direct sequencing of PCR-amplified 18S ribosomal gene DNA fragments from filtered sea-water has been successfully used to investigate the astounding diversity of these organisms. The recognition of many novel planktonic organisms is thus based solely on their 18S rDNA sequence. However, a species delimited by its 18S rDNA sequence might contain many cryptic species, which are highly differentiated in their protein coding sequences. Principal Findings: Here, we investigate the issue of species identification from one gene to the whole genome sequence. Using 52 whole genome DNA sequences, we estimated the global genetic divergence in protein coding genes between organisms from different lineages and compared this to their ribosomal gene sequence divergences. We show that this relationship between proteome divergence and 18S divergence is lineage dependant. Unicellular lineages have especially low 18S divergences relative to their protein sequence divergences, suggesting that 18S ribosomal genes are too conservative to assess planktonic eukaryotic diversity. We provide an explanation for this lineage dependency, which suggests that most species with large effective population sizes will show far less divergence in 18S than protein coding sequences. Conclusions: There is therefore a trade-off between using genes that are easy to amplify in all species, but which by their nature are highly conserved and underestimate the true number of species, and using genes that give a better description of the number of species, but which are more difficult to amplify. We have shown that this trade-off differs between unicellular and multicellular organisms as a likely consequence of differences in effective population sizes. We anticipate that biodiversity of microbial eukaryotic species is underestimated and that numerous ''cryptic species'' will become discernable with the future acquisition of genomic and metagenomic sequences
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