Enquête sur les petits métiers de la pêche en Languedoc-Roussillon

Le programme de recherche POLYPECHE, réalisé avec le support financier de la Fondation de France, a comme objet principal l'étude de la polyvalence de la pêche aux petits métiers dans la région Languedoc-Roussillon et ses implications en termes de durabilité et de gestion. Une connaissance actualisée des formes techniques et organisationnelles de cette polyvalence nous est apparue nécessaire. L'enquête présentée ici entend répondre à ce besoin. Elle a été réalisée d'octobre 2012 à janvier 2013 dans l'ensemble des prud'homies de la région auprès d'un échantillon de patrons pêcheurs. Les questions posées concernent les moyens humains et matériels des entreprises individuelles de pêche, les conditions d'accès et de maintien dans la profession, les pratiques de pêche, la perception des patrons pêcheurs sur les milieux exploités, leurs ressources, le système de gestion de l'activité. Elle a été complétée par une étude plus spécifique sur les conditions d'installation dans la profession de patron pêcheur petits métiers. Ce rapport présentera dans un premier temps les aspects méthodologiques de l'enquête et de son traitement statistique. Les résultats d'ensemble seront ensuite présentés et discutés. Des annexes présenteront ensuite l'étude sur les conditions d'installation dans la pêche aux petits métiers et enfin les résultats obtenus par prud'homie

Governance of marine protected areas in the least-developed countries : case studies from West Africa

ISSN 2070-7010International audienceThe need for effective governance of the marine protected areas (MPAs) in least developed countries (LDCs) is commensurate with the significant territorial stakes raised by their extensive maritime domain. Another significant challenge is the conservation of biodiversity and of ecosystems whose level of productivity is similar to that of coral reefs (e.g. in East Africa and Madagascar, the Red Sea, Maldives, Cambodia, and South Pacific islands), upwelling systems (e.g. in West Africa and Angola) and estuarine and delta ecosystems (e.g. in West and East Africa, Bangladesh and Myanmar). However, the overriding issue is to reconcile conservation and human presence as, in LDCs, human activities are tolerated in almost all MPAs covered by International Union for Conservation of Nature categories II-VI. Finally, issues related to identity claims and to the process of establishment of property and other legal entitlements on nature are gaining importance. A review of the literature on fisheries and MPAs governance showed how polysemous and vague the notion of governance was until very recently and how few or oversimplified were the analyses of MPA governance in the LDCs. However, only detailed analyses would allow the characterization of governance systems and identification of their weaknesses with the view to suggesting new governance arrangements and appropriate public policy options. Such analytical deficiencies may be explained by the lack of analytical frameworks capable of taking into account the plurality and intricacy of socio-economic organizations and institutions, the sociocultural features and the role of new mediators and "development brokers" that shape MPA governance in the LDCs. The deficiencies may also be explained by the fact that the dominating hierarchical governancesystems tend to underestimate the complexity of MPA governance systems. Therefore, it has been necessary to develop an analytical framework to study the governance of MPAs in the LDCs, drawing on four sources of inspiration: (i) the interactive fisheries governance approach; (ii) the risk governance approach; (iii) the socioanthropology of mediations and brokerage; and (iv) the governance analytical framework. The framework indicates the five issues that must be addressed in order to operationalize the concept of governance in LDC MPAs: (i) definition of the problem or the issue at stake; (ii) identification of the set of relevant governance norms; (iii) presentation of the actors involved in the governance process; (iv) highlighting the nodes around which actors' strategies converge; and (v) recalling the processes that have led to the current state of governance. This analytical framework makes it possible to characterize the governance system of each of the MPAs considered and to develop a typology of these systems. The characterization of different governance systems highlights their weaknessesand paves the way for new public policy options and, more generally, for the restructuring of governance to correct these weaknesses. However, prior to the development of the analytical framework and the characterization of governance systems, the main MPA governance principles and constraints, as well their legal context, must be clarified. The whole methodology was tested on three West African coastal and marine protected areas, which seemed to provide textbook cases illustrating the difficulties of governance in LDCs: the Banc d'Arguin National Park in Mauritania, the Saloum Delta Biosphere Reserve in Senegal, and the Bolama Bijagos Archipelago Biosphere Reserve in Guinea-Bissau. The analysis of demographic and economic constraints in these West African MPAs showed the importance of: (i) increasing population density and mobility; (ii) the intensification of resource exploitation; and (iii) and the openingof the MPA economy. The analysis of the legal and institutional contexts showed the international inspiration of the MPA objectives and conservation arrangements,and the syncretism of the legal system

Current observed global mean sea level rise and acceleration estimated from satellite altimetry and the associated measurement uncertainty

We present the latest release of the global mean sea level (GMSL) record produced by the French space agency Centre National d’Etudes Spatiales (CNES) and distributed on the AVISO+ website. This dataset is based on reprocessed along-track data, so-called L2P 21, of the reference missions TOPEX/Poseidon (TP) and Jason-1, Jason-2 and Jason-3. The L2P 21 CNES/AVISO+ GMSL record covers the period January 1993 to December 2021 and is now delivered with an estimate of its measurement uncertainties following the method presented in Ablain et al. (2019). Based on the latest calibration (Cal) and validation (Val) knowledge, we updated the uncertainty budget of the reference altimetry mission measurements and demonstrate that the CNES/AVISO+ GMSL record now achieves stability of performances of ± 0.3 mm yr−1 at the 90 % confidence level (C.L.) for its trend and ±0.05 mm yr−2 (90 % C.L.) for its acceleration over the 29 years of the altimetry record. Thanks to an analysis of the relative contribution of each measurement uncertainty budget contributor, i.e. the altimeter, the radiometer, the orbit determination and the geophysical corrections, we identified the current limiting factors to the GMSL monitoring stability and accuracy. We find that the radiometer wet troposphere correction (WTC) and the high-frequency errors with timescales shorter than 1 year are the major contributors to the GMSL measurement uncertainty over periods of 10 years (30 %–70 %), for both the trend and acceleration estimations. For longer periods of 20 years, the TP data quality is still a limitation, but more interestingly, the International Terrestrial Reference Frame (ITRF) realization uncertainties becomes dominant over all the other sources of uncertainty. Such a finding challenges the altimetry observing system as it is designed today and highlights clear topics of research to be explored in the future to help the altimetry community to improve the GMSL measurement accuracy and stability.</p

Origin and Evolution of GALA-LRR, a New Member of the CC-LRR Subfamily: From Plants to Bacteria?

The phytopathogenic bacterium Ralstonia solanacearum encodes type III effectors, called GALA proteins, which contain F-box and LRR domains. The GALA LRRs do not perfectly fit any of the previously described LRR subfamilies. By applying protein sequence analysis and structural prediction, we clarify this ambiguous case of LRR classification and assign GALA-LRRs to CC-LRR subfamily. We demonstrate that side-by-side packing of LRRs in the 3D structures may control the limits of repeat variability within the LRR subfamilies during evolution. The LRR packing can be used as a criterion, complementing the repeat sequences, to classify newly identified LRR domains. Our phylogenetic analysis of F-box domains proposes the lateral gene transfer of bacterial GALA proteins from host plants. We also present an evolutionary scenario which can explain the transformation of the original plant LRRs into slightly different bacterial LRRs. The examination of the selective evolutionary pressure acting on GALA proteins suggests that the convex side of their horse-shoe shaped LRR domains is more prone to positive selection than the concave side, and we therefore hypothesize that the convex surface might be the site of protein binding relevant to the adaptor function of the F-box GALA proteins. This conclusion provides a strong background for further functional studies aimed at determining the role of these type III effectors in the virulence of R. solanacearum

Extensive recombination events and horizontal gene transfer shaped the Legionella pneumophila genomes

<p>Abstract</p> <p>Background</p> <p><it>Legionella pneumophila </it>is an intracellular pathogen of environmental protozoa. When humans inhale contaminated aerosols this bacterium may cause a severe pneumonia called Legionnaires' disease. Despite the abundance of dozens of <it>Legionella </it>species in aquatic reservoirs, the vast majority of human disease is caused by a single serogroup (Sg) of a single species, namely <it>L. pneumophila </it>Sg1. To get further insights into genome dynamics and evolution of Sg1 strains, we sequenced strains Lorraine and HL 0604 1035 (Sg1) and compared them to the available sequences of Sg1 strains Paris, Lens, Corby and Philadelphia, resulting in a comprehensive multigenome analysis.</p> <p>Results</p> <p>We show that <it>L. pneumophila </it>Sg1 has a highly conserved and syntenic core genome that comprises the many eukaryotic like proteins and a conserved repertoire of over 200 Dot/Icm type IV secreted substrates. However, recombination events and horizontal gene transfer are frequent. In particular the analyses of the distribution of nucleotide polymorphisms suggests that large chromosomal fragments of over 200 kbs are exchanged between <it>L. pneumophila </it>strains and contribute to the genome dynamics in the natural population. The many secretion systems present might be implicated in exchange of these fragments by conjugal transfer. Plasmids also play a role in genome diversification and are exchanged among strains and circulate between different <it>Legionella </it>species.</p> <p>Conclusion</p> <p>Horizontal gene transfer among bacteria and from eukaryotes to <it>L. pneumophila </it>as well as recombination between strains allows different clones to evolve into predominant disease clones and others to replace them subsequently within relatively short periods of time.</p

Molecular Mimicry by an F-Box Effector of Legionella pneumophila Hijacks a Conserved Polyubiquitination Machinery within Macrophages and Protozoa

The ability of Legionella pneumophila to proliferate within various protozoa in the aquatic environment and in macrophages indicates a remarkable evolution and microbial exploitation of evolutionarily conserved eukaryotic processes. Ankyrin B (AnkB) of L. pneumophila is a non-canonical F-box-containing protein, and is the only known Dot/Icm-translocated effector of L. pneumophila essential for intra-vacuolar proliferation within both macrophages and protozoan hosts. We show that the F-box domain of AnkB and the 9L10P conserved residues are essential for intracellular bacterial proliferation and for rapid acquisition of polyubiquitinated proteins by the Legionella-containing vacuole (LCV) within macrophages, Dictyostelium discoideum, and Acanthamoeba. Interestingly, translocation of AnkB and recruitment of polyubiquitinated proteins in macrophages and Acanthamoeba is rapidly triggered by extracellular bacteria within 5 min of bacterial attachment. Ectopically expressed AnkB within mammalian cells is localized to the periphery of the cell where it co-localizes with host SKP1 and recruits polyubiquitinated proteins, which results in restoration of intracellular growth to the ankB mutant similar to the parental strain. While an ectopically expressed AnkB-9L10P/AA variant is localized to the cell periphery, it does not recruit polyubiquitinated proteins and fails to trans-rescue the ankB mutant intracellular growth defect. Direct in vivo interaction of AnkB but not the AnkB-9L10P/AA variant with the host SKP1 is demonstrated. Importantly, RNAi-mediated silencing of expression of SKP1 renders the cells non-permissive for intracellular proliferation of L. pneumophila. The role of AnkB in exploitation of the polyubiquitination machinery is essential for intrapulmonary bacterial proliferation in the mouse model of Legionnaires' disease. Therefore, AnkB exhibits a novel molecular and functional mimicry of eukaryotic F-box proteins that exploits conserved polyubiquitination machinery for intracellular proliferation within evolutionarily distant hosts

Proteomic Analysis of Growth Phase-Dependent Expression of Legionella pneumophila Proteins Which Involves Regulation of Bacterial Virulence Traits

Legionella pneumophila, which is a causative pathogen of Legionnaires' disease, expresses its virulent traits in response to growth conditions. In particular, it is known to become virulent at a post-exponential phase in vitro culture. In this study, we performed a proteomic analysis of differences in expression between the exponential phase and post-exponential phase to identify candidates associated with L. pneumophila virulence using 2-Dimentional Fluorescence Difference Gel Electrophoresis (2D-DIGE) combined with Matrix-Assisted Laser Desorption/Ionization–Mass Spectrometry (MALDI-TOF-MS). Of 68 identified proteins that significantly differed in expression between the two growth phases, 64 were up-regulated at a post-exponential phase. The up-regulated proteins included enzymes related to glycolysis, ketone body biogenesis and poly-3-hydroxybutyrate (PHB) biogenesis, suggesting that L. pneumophila may utilize sugars and lipids as energy sources, when amino acids become scarce. Proteins related to motility (flagella components and twitching motility-associated proteins) were also up-regulated, predicting that they enhance infectivity of the bacteria in host cells under certain conditions. Furthermore, 9 up-regulated proteins of unknown function were found. Two of them were identified as novel bacterial factors associated with hemolysis of sheep red blood cells (SRBCs). Another 2 were found to be translocated into macrophages via the Icm/Dot type IV secretion apparatus as effector candidates in a reporter assay with Bordetella pertussis adenylate cyclase. The study will be helpful for virulent analysis of L. pneumophila from the viewpoint of physiological or metabolic modulation dependent on growth phase