Ampelisca lusitanica (Crustacea: Amphipoda): new species for the Atlantic coast of Morocco

Background This study reports for the first time the presence of the Lusitanian ampeliscid amphipod Ampelisca lusitanica Bellan-Santini & Marques, 1986 in the northwestern Atlantic coast of Morocco. Methods Specimens were collected in January 2015 from intertidal rock pools along the El Jadida shoreline associated with the brown algae Bifurcaria bifurcata and Sargassum muticum. Results Systematic description of the species is presented, as well as a discussion of its ecological and geographical distribution. Conclusion This new finding extends the geographical distribution from the Lusitanian (Europe) to the Mauritanian (Africa) region and increases knowledge of the ecology and the global distribution of A. lusitanica found, previously, only on Portuguese and Spanish coasts.info:eu-repo/semantics/publishedVersio

A unified model for BAM function that takes into account type Vc secretion and species differences in BAM composition

Transmembrane proteins in the outer membrane of Gram-negative bacteria are almost exclusively β-barrels. They are inserted into the outer membrane by a conserved and essential protein complex called the BAM (for β-barrel assembly machinery). In this commentary, we summarize current research into the mechanism of this protein complex and how it relates to type V secretion. Type V secretion systems are autotransporters that all contain a β-barrel transmembrane domain inserted by BAM. In type Vc systems, this domain is a homotrimer. We argue that none of the current models are sufficient to explain BAM function particularly regarding type Vc secretion. We also find that current models based on the well-studied model system Escherichia coli mostly ignore the pronounced differences in BAM composition between different bacterial species. We propose a more holistic view on how all OMPs, including autotransporters, are incorporated into the lipid bilayer

Polychaete fauna from the intertidal zone of the Kneiss Islands (central Mediterranean Sea)

International audienc

Stock discrimination of <i>Chelidonichthys obscurus</i> (Triglidae) in the central Mediterranean Sea using morphometric analysis and parasite markers

Abstract Assessing fish stocks has important implications for fisheries management and conservation biology. Gurnards are marine demersal fish that commonly occur in the Mediterranean, but their population in this region remains to be quantified. This study examines the population structure of the longfin gurnard Chelidonichthys obscurus (Walbaum, 1792) in waters off eastern Tunisia, using morphometry and parasite assemblages. A total of 134 fish are investigated from two studied zones – the Gulf of Hammamet and the Gulf of Gabès. Discriminant analysis is used to compare gurnard populations in the two studied zones using 13 morphometric characters and the infection parameters of seven parasites. Morphometric analysis reveals strong spatial variations between the studied zones, providing evidence for the existence of an ecological differentiation along the eastern Tunisian coast. Mahalanobis distances show that body height, pectoral fin length and first dorsal fin length are the most salient morphometric characters for determining the position of samples from the Gulf of Gabès. The effectiveness of using parasites to study longfin gurnard stocks is uncertain. The use of short-lived parasites as biological tags is questionable, at least in the present case. Future research, based on complementary approaches such as otolith microchemistry and genetics, may improve our understanding of the global stock structure of longfin gurnard to suitably inform regional organizations involved in fisheries management.</jats:p

Spatial distribution and abundance of intertidal benthic macrofauna in the Kneiss Islands (Gulf of Gabès, Tunisia)

International audienceThe Kneiss islands, located in the Gulf of Gabès (Southeastern Tunisia), represent a site of international interest in terms of their ornithological diversity (Important Bird Area, SPAMI and Ramsar Site) and are heavily exploited for clams and fish resources. In an effort to assess the ecological status of the intertidal ecosystem, and to facilitate management and conservation of the resources, an ecological survey of the macrobenthic component was carried out from January to March 2012. This study involved identifying the benthic fauna and assessing the spatial distribution on the southern unperturbed Zostera noltei mudflats by human activities. A total of 102 macrobenthos taxa is identified at 19 stations with a predominance of crustaceans (37%), polychaetes (27%) and molluscs (23%). The AMBI index shows that the area has a good ecological status. Cluster Analysis and Multidimensional scaling identify three benthic assemblages on the basis of their faunal similarity in relation to sediment types and organic matter contents.RésDistribution spatiale et abondance de la macrofaune intertidale des îles Kneiss (Golfe de Gabès, Tunisie). La distribution spatiale et l'abondance des communautés macrobenthiques des îles Kneiss (Golfe de Gabès, Tunisie) ont été étudiées. Par leur diversité ornithologique, les îles Kneiss présentent un intérêt international (Site Ramsar, ZICO, ASPIM), mais l'activité de collecte de la palourde (Ruditapes decussatus) et la pêche intensive au chalut benthique ont conduit à la surexploitation des ressources. Pour évaluer l'état écologique de cet écosystème et faciliter la gestion et la conservation des ressources, une étude écologique de la composante benthique a été réalisée. La macrofaune benthique des vasières des îles Kneiss a été étudiée de janvier à mars 2012 dans une zone d'herbier de Zostera noltei peu perturbée par des activités humaines. Un total de 102 taxa de macrobenthos a été identifié dans 19 stations, avec une dominance de crustacés Amphipodes (37%), des Annélides Polychètes (27%) et des Mollusques (23%). L'indice biotique AMBI a montré que la région est en bon état écologique. Trois assemblages benthiques ont été identifiés par la classification ascendante hiérarchique et le positionnement multidimensionnel sur la base de leur spécificité faunistique, le type de sédiments et les contenus en matière organique

Study of nano bioactive glass for use as bone biomaterial comparison with micro bioactive glass behaviour

International audienceThis research is based on the study of bioactivity kinetic in function of the glass particles size. Bioactive glasses have been elaborated in the ternary system SiO2-CaO-P2O5. Nano bioactive glass and micro bioactive glass have been synthesized by using two different processes. They are destined for use as bone biomaterials. The comparison was focused on the kinetic of the development of a calcium phosphate layer on their surfaces after immersion in a Simulated Body Fluid (SBF). The first bioactive glass BG is a melting-made glass with a particles size of about 60 μm. The second bioactive glass NBG is a sol-gel made glass through an emulsion system of synthesized particles of about 110 nm. The growing of the calcium phosphate layer at the surface of the glasses has been followed using several physicochemical techniques. Obtained results show the development of a calcium phosphate layer similar to carbonated hydroxyapatite. It crystallises in a hexagonal system with an P63/m space group. While melting-made glass needs 14 days to develop carbonated hydroxyapatite like crystal, sol-gel needs only 3 days to develop similar crystals. This difference offers wide opportunities and complementarities for the use of nano or micro bioactive glasses in the biomedical field. © Published under licence by IOP Publishing Ltd

Study of nano bioactive glass for use as bone biomaterial comparison with micro bioactive glass behaviour

Abstract This research is based on the study of bioactivity kinetic in function of the glass particles size. Bioactive glasses have been elaborated in the ternary system SiO2-CaO-P2O5. Nano bioactive glass and micro bioactive glass have been synthesized by using two different processes. They are destined for use as bone biomaterials. The comparison was focused on the kinetic of the development of a calcium phosphate layer on their surfaces after immersion in a Simulated Body Fluid (SBF). The first bioactive glass BG is a melting-made glass with a particles size of about 60 μm. The second bioactive glass NBG is a sol-gel made glass through an emulsion system of synthesized particles of about 110 nm. The growing of the calcium phosphate layer at the surface of the glasses has been followed using several physicochemical techniques. Obtained results show the development of a calcium phosphate layer similar to carbonated hydroxyapatite. It crystallises in a hexagonal system with an P63/m space group. While melting-made glass needs 14 days to develop carbonated hydroxyapatite like crystal, sol-gel needs only 3 days to develop similar crystals. This difference offers wide opportunities and complementarities for the use of nano or micro bioactive glasses in the biomedical field.</jats:p