Le thon : enjeux et stratégies pour l'océan Indien

La pêche réunionnaise est, depuis les cinq dernières années, placée à contre temps complet de l'immense majorité des autres pêcheries communautaires (Union européenne), dans une situation de développement rapide de l'ensemble de ses segments (pêche artisanale, grande pêche hauturière antarctique, pêche palangrière). Le plus rapide de ces développements est certainement celui du segment palangrier qui, né il y a 5 ans, va cette année 1996 égaliser, voire dépasser la pêche artisanale, soit près de 1 500 t/an. Cette pêcherie est composée par 9 armements alignant 28 navirees de 12 à 33 m dont 20 sont opérationnels en 1996. Sa production est constituée pour les espèces majeures, de 2/3 d'espadons et de 1/3 de thonidés. La zone de pêche exploitée est très vaste, depuis l'équateur jusqu'au 35°Sud. Les rendements, après avoir présenté une augmentation très significative de 1992 à 1994, présentent un tassement certain de 1994 à 1996 pour tous les navires de la flotte. Ce développement se poursuit aujourd'hui au niveau de la région COI par un développement des flottilles palangrières régionales, amorcé aux Seychelles et bientôt à Maurice. Un équilibre d'exploitation pérenne doit impérativement s'appuyer sur les recherches halieutiques et socio-économiques d'accompagnement de cette pêcherie. (Résumé d'auteur

The quadrupole resonator: Construction, RF System Field Calculations and First Applications

The quadrupole resonator allows measurement of the RF properties of superconducting (sc) films deposited on disk-shaped metallic substrates. We describe the construction of the apparatus, the brazing and electron-beam welding procedures, the arrangements for compensating mechanical tolerances of samples and for assuring reproducible sample illumination. We explain the special features of the RF sy stem and give the results of field calculations with a 3D cavity code. Finally we present first measurements of Nb on Cu film samples and compare them with calibrations done with a bulk Nb sample

Longitudinal investigation of Salmonella spp. from farm to fork in the pig industry in Reunion Island

Salmonella is, after Campylobacter, the most reported zoonotic pathogen in Europe. Pork meat is frequently incriminated in salmonellosis. However, asymptomatic carrying of Salmonella by pigs makes its detection difficult. Despite its tropical situation, pig industry of Reunion Island is also concerned by this public health burden

Networks with fourfold connectivity in two dimensions

The elastic properties of planar, C4-symmetric networks under stress and at nonzero temperature are determined by simulation and mean field approximations. Attached at fourfold coordinated junction vertices, the networks are self-avoiding in that their elements (or bonds) may not intersect each other. Two different models are considered for the potential energy of the elements: either Hooke’s law springs or flexible tethers (square well potential). For certain ranges of stress and temperature, the properties of the networks are captured by one of several models: at large tensions, the networks behave like a uniform system of square plaquettes, while at large compressions or high temperatures, they display many characteristics of an ideal gas. Under less severe conditions, mean field models with more general shapes (parallelograms) reproduce many essential features of both networks. Lastly, the spring network expands without limit at a two-dimensional tension equal to the force constant of the spring; however, it does not appear to collapse under compression, except at zero temperature

Prevalence and risk indicators associated with Salmonella infection in farrow-to-finish farm in Reunion Island

Salmonella is the second cause of foodborne diseases in France and pork products are regularly incriminated. For the implementation of control measures in farms, it is necessary to better understand the risks of infection of pigs by Salmonella at farms. Our epidemiological study aims to determine Salmonella prevalence of fattening pigs in Reunion Island, oversea territory of France, and the main risk indicators for pig infection. Fifty farms (farrow-to finish and multiplier) were randomly selected and visited 4 times: at slaughtered previous batch, after cleaning and disinfection, beginning and end of the fattening period for the studied batch. Pools of fresh faeces, gauze socks and gauze swabs were sampled to assess the bacteriological status of these pig farms. A questionnaire was submitted to farmers and analysed for the further identification of risk indicators

The translational regulator dFMRP interacts with epidermal growth factor receptor to regulate apoptosis in Drosophila

poster abstractPosttranscriptional gene regulation is required for all aspects of cellular and tissue development and is a major mechanism underlying many diseases ranging from neurological disorders to cancer. The translational repressor fragile x mental retardation protein (FMRP) is ubiquitously expressed throughout development but is silenced in Fragile X Syndrome, an autism spectrum disorder. Interestingly, high levels of FMRP have recently been identified in human metastatic breast cancer. FMRP overexpression in these patients is directly correlated with increased lung metastasis suggesting a direct role for translational regulation both in cell proliferation and in invasive cell migration. Interestingly, however, FMRP can promote both proliferation and apoptosis. To dissect FMRP’s role in cancer development and progression, we are exploiting the powerful genetic system of Drosophila. Drosophila is an excellent model organism for human diseases associated with FMRP due to the strong evolutionary conservation of the fragile x mental retardation gene 1 which encodes this protein. dFMRP was overexpressed in the Drosophila imaginal wing disc, an epithelial tissue model. Contrary to a role in proliferation, overexpression of dFMRP leads to obvious cell loss in the adult wing and an increase in apoptotic markers. Using a combinatorial genetic screen, we have identified genes which are able to suppress this apoptotic phenotype and thus may be important for FMRP-­‐dependent tumorigenesis. Our focus is now on the epidermal growth factor receptor (EGFR) signaling pathway since blocking this mechanism is able to completely rescue the dFMRP-­‐overexpression wing defects. Clonal analysis reveals that dFMRP overexpressing cells survive their dFMRP-­induced apoptotic programming when co-­‐expressing a dominant negative form of EGFR. Additional clonal analyses are being used to explore the potential significance of this survival on tumor formation and metastasis