Search

Due to environmental regulations, antifouling marine coatings must be gradually replaced by biocide-free coatings. Marine organisms weakly adhere to fouling release coatings, presenting a low surface free energy and a high elasticity, so they can be readily removed by the sheer force of water. Currently, these materials are mainly composed of petrochemical polymers, such as silicone or fluoropolymers, with hydrophilic polymers as additives. However, following the ever-increasing environmental concerns, the research on new, alternative, eco-friendly coatings is oriented towards the use of biobased polymers from renewable resources. Two main families have been studied: polyhydroxyalkanoates (PHAs) and polysaccharides. PHAs are produced by bacteria in stressful conditions, while polysaccharides are extracted from plants, animals, or micro-organisms such as bacteria, in which case they are called exopolysaccharides (EPS). Since the use of these polymers is a non-toxic approach to controlling fouling colonization, this review provides an overview of these biobased polymers for their applications in new anti-adhesive marine coatings.

Nanoparticles have recently emerged as valuable tools in biomedical imaging techniques. Here PEGylated and fluorinated nanocapsules based on poly(3-hydroxyalkanoate) containing a liquid core of perfluorooctyl bromide PFOB were formulated by an emulsion-evaporation process as potential 19F MRI imaging agents. Unsaturated poly(hydroxyalkanoate), PHAU, was produced by marine bacteria using coprah oil and undecenoic acid as substrates. PHA-g-(F; PEG) was prepared by two successive controlled thiol-ene reactions from PHAU with firstly three fluorinated thiols having from 3 up to 17 fluorine atoms and secondly with PEG-SH. The resulting PHA-g-(F; PEG)-based PFOB nanocapsules, with a diameter close to 250–300 nm, are shown to be visible in 19F MRI with an acquisition time of 15 min. The results showed that PFOB-nanocapsules based on PHA-g-(F; PEG) have the potential to be used as novel contrast agents for 19F MRI.

Two novel strains, HW T2.11T and HW T5.17T, were isolated from decaying wood (forest of Champenoux, France). Study of the 16S rRNA sequence similarity indicated that the novel strains belong to the genus Acidisoma. The sequence similarity of the 16S rRNA gene of HW T2.11T with the corresponding sequences of A. tundrae and A. sibiricum was 97.30% and 97.25%, while for HW T5.17T it was 96.85% and 97.14%, respectively. The DNA G+C contents of the strains were 62.32–62.50%. Cells were Gram-negative coccobacilli that had intracellular storage granules (poly-3-hydroxybutyrate (P3HB)) that confer resistance to environmental stress conditions. They were mesophilic and acidophilic organisms growing at 8–25 °C, at a pH of 2.0–6.5, and were capable of using a wide range of organic compounds and complex biopolymers such as starch, fucoidan, laminarin, pectin and cellulose, the latter two being involved in wood composition. The major cellular fatty acid was cyclo C19:0ω8c and the major quinone was Q-10. Overall, genome relatedness indices between genomes of strains HW T2.11T and HW T5.17T (Orthologous Average Nucleotide Identity (OrthoANI) value = 83.73% and digital DNA-DNA hybridization score = 27.5%) confirmed that they belonged to two different species. Genetic predictions indicate that the cyclopropane fatty acid (CFA) pathway is present, conferring acid-resistance properties to the cells. The two novel strains might possess a class IV polyhydroxyalcanoate (PHA) synthase operon involved in the P3HB production pathway. Overall, the polyphasic taxonomic analysis shows that these two novel strains are adapted to harsh environments such as decaying wood where the organic matter is difficult to access, and can contribute to the degradation of dead wood. These strains represent novel species of the genus Acidisoma, for which the names Acidisoma silvae sp. nov. and Acidisoma cellulosilytica sp. nov. are proposed. The type strains of Acidisoma silvae and Acidisoma cellulosilytica ar

Cet ouvrage constitue un parcours interprétatif de l'expression de l'identité culturelle galicienne dans la littérature, l'éducation et les médias, à travers des discours de natures variées. Les regards croisés sur Valle-Inclán, Torrente Ballester ou Celso Emilio Ferreiro, l'ouvrage scolaire de Manuel Murguía, la politique éditoriale de la revue Nós ou encore les spots publicitaires du début du XXIème siècle apportent des réponses spécifiques à des questionnements récurrents sur l'identité culturelle galicéenne.

The majority of the critically endangered chimpanzees (Pan troglodytes verus) occur outside protected areas. Ensuring their long-term survival in such areas implies addressing people-chimpanzee coexistence challenges. Using origin data of confiscated chimpanzees from two chimpanzee sanctuaries in West Africa, i.e. the Chimpanzee Conservation Center (CCC), Guinea and the Tacugama Chimpanzee Sanctuary, Sierra Leone, and forest loss data from 2001 to 2015, we highlight how deforestation exacerbates interactions between people-chimpanzees and acts as a driver for the killing and capture of chimpanzees in the region. Finally, we present results from a systematic camera trapping survey (24 camera traps deployed across 27 1.25x1.25 km grids) conducted in the Moyamba district in south-western Sierra Leone in an area dominated by subsistence agricultural activities and practically devoid of forest. We employed a hierarchical Bayesian framework accounting for spatial autocorrelation to explore ecological and anthropogenic factors influencing chimpanzee relative abundance across the landscape. Our findings revealed that chimpanzees in such landscapes, where people are relatively tolerant of their presence, tend to avoid roads, including untarmacked secondary roads, and prefer to range in close proximity to more intact habitats such as swamps. Unexpectedly, they showed no preference for abandoned settlements where fruit orchard persist. Finally, although chimpanzees in this area did not avoid human settlements or areas frequented by people, areas of spatial overlap between the two species revealed temporal divergence in utilization. Altogether, these studies emphasize the urgent need to understand better factors that influence chimpanzee abundance and distribution outside protected areas, especially in the context of the rate of forest loss, and for aligning land use planning and infrastructure development to serve both the needs of people and chimpanzees.

Classical ecology provides principles for construction and function of biological communities, but to what extent these apply to the animal-associated microbiota is just beginning to be assessed. Here, we investigated the influence of several well-known ecological principles on animal-associated microbiota by characterizing gut microbial specimens from bilaterally symmetrical animals (