The deep-sea macrobenthos on the continental slope of the northwestern Mediterranean Sea: a quantitative approach

As part of the ECOMARGE operation (J.G.O.F.S. France), macrobenthic assemblages in the Toulon Canyon were described and quantified on the basis of sampling carried out between 250 and 2000 m depth on the Mediterranean continental slope. Results show that Mediterranean bathyal assemblages are made up mainly of continental shelf eurybathic species. The qualitative and quantitative composition of populations varies with depth on the slope and also varies with station position at equivalent depth, whether on the flanks or in the canyon channel. Various analyses have provided evidence on the factors responsible for this population distribution pattern. No single factor emerges as predominant, but rather a group of factors, which are related to the nature and origin of sediments and more particularly their grain size distribution, geochemical composition and mode of transportation and sedimentation (benthic nepheloid or originating from the water column), act in conjunction to determine the pattern. Comparison with ocean continental slopes shows that in the Mediterranean Sea the absence of tidal current modifies the trophic structure of the macrobenthic assemblages, which are characterized by a dominance of surface and subsurface deposit feeders as compared to a dominance of suspension feeders and carnivores in the upper and median part of the slope in the ocean. Surface dumping of dredge spoil at the canyon head and channelling of waste induces an increase of organic matter and pollutant concentrations in sediment from the upper part of the canyon channel but does not give rise to any marked population degradation

Elemental analysis for profiling counterfeit watches

Counterfeit watches are products of illicit activity and contain traces of their production and distribution. Traces provide pertinent information through one of their fundamental characteristics: the ability to reveal links between specimens or cases. The aim of this study was to develop an analytical strategy to obtain the elemental composition of watchcases, by analysing a selection of 35 counterfeit watches. We propose a methodology based on multivariate statistical analysis of chemical results that discriminates between watches from common and different origins, and, ultimately, classifies them into chemical groups. All watchcases were analysed using inductively coupled plasma mass spectrometry (ICP-MS), providing representative descriptive data on the composition of watchcases. Several multivariate approaches were assessed, considering different scenarios, each using a different set of variables. It appeared that the model that performed best in terms of classification criteria could be misleading, especially in an exploratory context that focuses on the production of intelligence. At the end of the day, hierarchical cluster analysis (HCA) allowed us to classify the specimens into 14 chemical classes. Information gained through chemical analysis revealed several links between the specimens. This initial study was performed on a very limited number of watches. Although still in the developmental stage, our approach exhibits promising capabilities and encourages chemical profiling of counterfeit watches on larger scale

Forensic intelligence on illicit markets: the example of watch counterfeiting

Counterfeit luxury fashion goods have rarely been the subject of scientific studies. Very little is known about the mechanisms of this illicit market despite the apparent prevalence and their adverse consequences. Counterfeit watches remain one of the preferred targets in the luxury goods segment. The study of marks or traces in a forensic intelligence perspective can contribute to an improved understanding of the phenomenon. The aim of our research was to highlight different types of links that can be drawn between specimens of counterfeit watches, to carry out a thorough study of the information conveyed by the revealed links, to study their complementarity and to get an understanding of the intelligence that can be produced from these pieces of information. Thirty-five counterfeit watches of a commonly counterfeit watch brand including seven popular models were studied in this research. Chemical and physical links were found that corroborated existing knowledge and also revealed new connections between different seizures or specimens. The comparison of chemical and physical features combined with spatiotemporal information on the seized watches enabled us to produce intelligence disclosing possible aspects of the structure and the organisation of production and distribution channels. We were able to reveal or confirm links between watches that were previously unknown or uncertain and demonstrated the interconnection of all watches on a chemical and/or physical level, suggesting an overhead organised network with substructures. Despite the limited set of specimens that was considered, this study illustrates that forensic intelligence on this illicit market can be used to support consistent decision-making from all the key-players involved in the anti-counterfeiting process

Modified bacterial reaction centers

Pigments of borohydride-treated reaction centers of Rhodobacter sphaeroides R 26 and Rhodopseudomonas viridis were analyzed by HPLC with polychromatic detection. In both species, pigment composition and contents were unchanged. Reaction centers from Rhodobacter sphaeroides R26 were prepared in which bacteriochlorophylls (BA,B) and bacteriopheophytins (HA,B) were exchanged with their potential borohydride products reduced at C-31. [3-Hydroxyethyl]-BChl a exchanges selectively into the BA,B pockets, and 31-OH-BPh a to the HA,B pockets. Stable reaction centers are obtained in both cases. A comparison of the absorption and circular dichroism spectra of reaction centers after exchange with 31-OH pigments, and of borohydride-modified reaction centers, reveal distinct differences. It is concluded that during borohydride reduction none of the pigments is chemically modified or extracted from the reaction centers

Identification of tissue-specific and common methylation quantitative trait loci in healthy individuals using MAGAR

Background Understanding the influence of genetic variants on DNA methylation is fundamental for the interpretation of epigenomic data in the context of disease. There is a need for systematic approaches not only for determining methylation quantitative trait loci (methQTL), but also for discriminating general from cell type-specific effects. Results Here, we present a two-step computational framework MAGAR (https://bioconductor.org/packages/MAGAR), which fully supports the identification of methQTLs from matched genotyping and DNA methylation data, and additionally allows for illuminating cell type-specific methQTL effects. In a pilot analysis, we apply MAGAR on data in four tissues (ileum, rectum, T cells, B cells) from healthy individuals and demonstrate the discrimination of common from cell type-specific methQTLs. We experimentally validate both types of methQTLs in an independent data set comprising additional cell types and tissues. Finally, we validate selected methQTLs located in the PON1, ZNF155, and NRG2 genes by ultra-deep local sequencing. In line with previous reports, we find cell type-specific methQTLs to be preferentially located in enhancer elements. Conclusions Our analysis demonstrates that a systematic analysis of methQTLs provides important new insights on the influences of genetic variants to cell type-specific epigenomic variation

Identification of tissue-specific and common methylation quantitative trait loci in healthy individuals using MAGAR.

BackgroundUnderstanding the influence of genetic variants on DNA methylation is fundamental for the interpretation of epigenomic data in the context of disease. There is a need for systematic approaches not only for determining methylation quantitative trait loci (methQTL), but also for discriminating general from cell type-specific effects.ResultsHere, we present a two-step computational framework MAGAR ( https://bioconductor.org/packages/MAGAR ), which fully supports the identification of methQTLs from matched genotyping and DNA methylation data, and additionally allows for illuminating cell type-specific methQTL effects. In a pilot analysis, we apply MAGAR on data in four tissues (ileum, rectum, T cells, B cells) from healthy individuals and demonstrate the discrimination of common from cell type-specific methQTLs. We experimentally validate both types of methQTLs in an independent data set comprising additional cell types and tissues. Finally, we validate selected methQTLs located in the PON1, ZNF155, and NRG2 genes by ultra-deep local sequencing. In line with previous reports, we find cell type-specific methQTLs to be preferentially located in enhancer elements.ConclusionsOur analysis demonstrates that a systematic analysis of methQTLs provides important new insights on the influences of genetic variants to cell type-specific epigenomic variation

Les politiques des sciences. Séminaire alternatif

Michel Agier, Mathieu Arnoux, Alban Bensa, Alain Blum, Simona Cerutti, Francis Chateauraynaud, Robert Descimon, Nicolas Dodier, Jean-Claude Galey, Nancy L. Green, Christian Jouhaud, Christian Topalov, directeurs d’étudesIsabelle Backouche, Juliette Cadiot, Fanny Cosandey, Sophie Desrosiers, André Gunthert, Liora Israël, Cyril Lemieux, Mary Picone, Sylvain Piron, maîtres de conférencesIrène Bellier, directrice de recherche au CNRSMichel Barthélémy, Elie Haddad, Cédric Lomba, Birgit Müller, Sop..

The Drosophila melanogaster host model

The deleterious and sometimes fatal outcomes of bacterial infectious diseases are the net result of the interactions between the pathogen and the host, and the genetically tractable fruit fly, Drosophila melanogaster, has emerged as a valuable tool for modeling the pathogen–host interactions of a wide variety of bacteria. These studies have revealed that there is a remarkable conservation of bacterial pathogenesis and host defence mechanisms between higher host organisms and Drosophila. This review presents an in-depth discussion of the Drosophila immune response, the Drosophila killing model, and the use of the model to examine bacterial–host interactions. The recent introduction of the Drosophila model into the oral microbiology field is discussed, specifically the use of the model to examine Porphyromonas gingivalis–host interactions, and finally the potential uses of this powerful model system to further elucidate oral bacterial-host interactions are addressed