Éditeur(s) : Elsevier Sci Ltd
Résumé : Many questions remain unanswered regarding RNAi-based mechanisms and dsRNA-induced antiviral immune responses in penaeid shrimp. In this study, we report the characterization in the white leg shrimp Litopenaeus vannamei of RNAi pathway associated proteins Lv-Ago 1 and Lv-Ago 2, two members of the Argonaute family of proteins, as well as Lv-sid 1, the first shrimp homologue of Sid-1, a membrane channel-forming protein implicated in the cellular import of dsRNA. To decipher their functional implication in RNAi-related phenomena, we monitored their relative expression following stimulation by specific and non-specific RNA duplexes of diverse length. The findings show that the length of small RNA duplexes plays a critical role in the activation of both RNAi-related and innate antiviral responses. They also suggest that these two mechanisms of antiviral response may activate the same pathway, requiring Lv-Sid 1 and Lv-Ago 2 induction. (C) 2010 Elsevier Ltd. All rights reserved.
Developmental And Comparative Immunology (0145-305X) (Elsevier Sci Ltd), 2010-11 , Vol. 34 , N. 11 , P. 1209-1218

Droits : 2010 Elsevier Ltd All rights reserved.
http://archimer.ifremer.fr/doc/00015/12652/9587.pdf
DOI:10.1016/j.dci.2010.06.017
http://archimer.ifremer.fr/doc/00015/12652/

Éditeur(s) : HAL CCSD Elsevier
Résumé : Handheld energy dispersive portable X-ray spectrometers (pXRF) are generally designed and used for qualitative survey applications. We developed shipboard quantitative analysis protocols for pXRF and employed the instrument to make over 2000 individual abundance measurements for a selection of major and trace elements on over 1200 m of recovered core during the eight weeks of the International Ocean Discovery Program (IODP) Expedition 352 to the Izu-Bonin forearc. pXRF analytical performance, accuracy and precision were found to be the same on powdered rock samples and on freshly cut rock surfaces, and sample results were similar within error to measurements made via shipboard ICP-OES analysis save at low abundance levels for a few elements. Instrument performance was optimal for elements between Z = 19 and Z = 40, and the system yielded reproducible data for K, Ca, Ti, V, Cr, Mn, Fe, Cu, Zn, Rb, Sr, and Zr on both powdered samples and rock surfaces. Working curves developed via pXRF measurement of a suite of geologic standard reference materials and well-characterized lavas permitted accurate quantitative measurements for many of the examined elements on both sample powders and rock surfaces. Although pXRF has been sporadically employed on previous cruises, Expedition 352 is the first time a detailed, high-density chemostratigraphy of recovered core samples was collected using pXRF measurements of rock core surfaces. These high-resolution data allowed the recognition of chemically distinct eruptive units in near real-time. The rapid identification of geochemical trends vastly improved our selection of samples for shipboard and shore-based analysis, permitted a more comprehensive interpretation of our Expedition results, and provided key decision-making information for drilling operations.
ISSN: 0009-2541

hal-01553188
https://hal.archives-ouvertes.fr/hal-01553188
DOI : 10.1016/j.chemgeo.2017.01.007

Éditeur(s) : HAL CCSD Taylor & Francis
Résumé : International audience
ternational Ocean Discovery Program (IODP) Expedition 352 recovered a high-fidelity record of volcanism related to subduction initiation in the Bonin fore-arc. Two sites (U1440 and U1441) located in deep water nearer to the trench recovered basalts and related rocks; two sites (U1439 and U1442) located in shallower water further from the trench recovered boninites and related rocks. Drilling in both areas ended in dolerites inferred to be sheeted intrusive rocks. The basalts apparently erupted immediately after subduction initiation and have compositions similar to those of the most depleted basalts generated by rapid sea-floor spreading at mid-ocean ridges, with little or no slab input. Subsequent melting to generate boninites involved more depleted mantle and hotter and deeper subducted components as subduction progressed and volcanism migrated away from the trench. This volcanic sequence is akin to that recorded by many ophiolites, supporting a direct link between subduction initiation, fore-arc spreading, and ophiolite genesis.
ISSN: 0020-6814

hal-01685628
https://hal.archives-ouvertes.fr/hal-01685628
DOI : 10.1080/00206814.2016.1276482

Éditeur(s) : Pêche thonière et dispositifs de concentration de poissons, Caribbean-Martinique, 15-19 Oct 1999
Résumé : Over the last 16 years, the Secretariat of the Pacific Community (SPC - formerly the South Pacific Commission) has been developing and providing information on mid-water fishing techniques targeting the larger, deeper-swimming tunas that aggregate around FADs. SPC masterfishermen have conducted in-country fishing trials to test methods, such as vertical longlines, and train local fishermen in their construction and use. Vertical longline catch rates have varied considerably due to a range of reasons with no catches reported in some locations, or just sharks, to highs of over 6.5 kg /10 hooks/hour being recorded in other locations. Other methods like drop-stone, palu-ahi, and single-hook drifting lines have been developed within the region, with SPC adopting and transferring this technology to other locations. To further disseminate this information, SPC has recently published a technical manual outlining a range of mid-water fishing gears and techniques that can be used in association with FADs. An outline of the main gears and techniques with catch data where available is presented, with factors influencing catches discussed based on the findings of SPC masterfishermen over the years.

Droits : info:eu-repo/semantics/openAccess
http://archimer.ifremer.fr/doc/00042/15295/12653.pdf
http://archimer.ifremer.fr/doc/00042/15295/

Éditeur(s) : Pêche thonière et dispositifs de concentration de poissons, Caribbean-Martinique, 15-19 Oct 1999 15-19 octobre 1999
Résumé : In the area served by the Secretariat of the Pacific Community (SPC), which includes 22 Pacific Island countries and territories, anchored FADs have been used since the late 1970s. First introduced from the Philippines, via Hawaii, they were quickly adopted by both industrial and artisanal fisheries sectors : in 1984 more than 600 anchored FADs had been deployed in the region. Since these early days, the development of the technique by the industrial and the artisanal sectors have followed parallel paths with little interaction. In the industrial private sector, companies are funding, deploying and monitoring their own FADs. For some fishing companies, using purse seiners and pole-and-line vessels, from the Solomon Islands or Papua-New-Guinea, these FADs have become a necessity. FAD programmes for small-scale fisheries have been almost exclusively run by the public sector, with technical support from regional and international development agencies and financial assistance from overseas funding agencies. These programmes have had mixed successes : becoming an on-going and essential tool in some places like French Polynesia or Guam; or being momentarily suspended, like in Vanuatu or Tonga, because of the lack of funds, partly due to the scarcity of proven economic return to the fishing communities. This document is an attempt to synthesise the current information on these very diverse situations, including technical, economical and social considerations.

Droits : Ifremer
http://archimer.ifremer.fr/doc/00042/15283/12669.pdf
http://archimer.ifremer.fr/doc/00042/15283/

Éditeur(s) : Elsevier
Résumé : injection of non-specific dsRNA initiates a broad-spectrum innate antiviral immune response in the Pacific white shrimp, Litopenaeus vannamei, however, the receptor involved in recognition of this by-product of viral infections remains unknown. In vertebrates, dsRNA sensing is mediated by a class of Toll-like receptors (TLRs) and results in activation of the interferon system. Because a TLR (lToll) was recently characterized in L. vannamei, we investigated its potential role in dsRNA recognition. We showed that injection of non-specific RNA duplexes did not modify lToll gene expression. A reverse genetic approach was therefore implemented to study its role in vivo. Silencing of lToll did not impair the ability of nonspecific dsRNA to trigger protection from white spot syndrome virus and did not increase the shrimp susceptibility to viral infection, when compared to controls. In contrast, gene-specific dsRNA injected to specifically silence lToll expression activated an antiviral response. These data strongly suggest that shrimp lToll plays no role in dsRNA-induced antiviral immunity. (C) 2009 Elsevier Ltd. All rights reserved.
Developmental & Comparative Immunology (0145-305X) (Elsevier), 2009-07 , Vol. 33 , N. 7 , P. 806-810

Droits : 2009 Elsevier Ltd All rights reserved.
http://archimer.ifremer.fr/doc/2009/publication-6428.pdf
DOI:10.1016/j.dci.2009.02.005
http://archimer.ifremer.fr/doc/00000/6428/