Spring production of Calanus finmarchicus at the Iceland-Scotland Ridge

Distribution and reproduction activity of the calanoid copepod Calanus finmarchicus were studied in the waters between Scotland and Iceland in April 1997 during the expected time of the animals' ascent to surface waters following diapause. Ascent was taking place on both sides of the Iceland-Scotland Ridge, apparently from two separate overwintering centers. The population on the Faroe Shelf (FS) most likely came from the overwintering population in the Faroe Shetland Channel (FSC). Per capita egg production was highest on the FS (> 30 eggs female -1d-1) and lowest in the Iceland Basin (10 eggs female -1d-1). The maximum clutch size recorded was on the FS (145 eggs). As the maximum clutch sizes that females produced were between 40% and 77% (area averages of the station maximum rates) of their size-specific reproduction potential, it is argued that egg production rates were generally food-limited. Chlorophyll a concentrations were, at all but one station, under 1 ugL-1. Chlorophyll-based ingestion could, theoretically, support the observed average egg production rates in the Iceland Basin and on the FS but only about 30% of the observed production at the stations in the East Icelandic Current (EIC). The carbon assimilated through ingestion of phytoplankton, Calanus own eggs andnauplii in the EIC was estimated to be too low to support the frequently observed production of clutches consisting of over 100 eggs. Cannibalism on eggs and nauplii was not likely to have constituted a significant component of dietary carbon intake. However, a combination of feeding and assimilation of reserved lipid remaining from overwintering could be sufficient to explain the observed per capita egg production rates. C. finmarchicus copepod stages 1-3 were only recorded in considerable numbers only on the FS. This suggests higher survival rates of eggs in the shelf waters

La musique en Picardie du XIVe au XVIIe siècle

Pendant plusieurs siècles qui vont de l'édification des grandes cathédrales gothiques à la fin du règne d'Henri IV, la Picardie fut le berceau d'une production musicale fascinante. En témoignent des sources musicales incontournables (le graduel 239 de Laon), la lyrique profane des trouvères picards, les 'organa' de l''Ars vetus' ou la polyphonie de la Renaissance. Trois siècles durant, des générations de chantres formés dans des maîtrises picardes allaient devenir des interprètes recherchés et des compositeurs adulés. Ils envahissent les plus prestigieuses institutions musicales européennes, constituant une nation éclatée de musiciens que l'histoire dira " franco-flamands ". Cet ouvrage tente de tracer les conditions de l'émergence de ces générations, en parcourant un vaste territoire aux frontières fluctuantes, en scrutant les rares sources conservées, en visitant les lieux de formation et de pratique, en suivant des destins pour les uns banals, pour les autres brillants

Iron-Regulated Lysis of Recombinant Escherichia coli in Host Releases Protective Antigen and Confers Biological Containment▿

The use of a recombinant bacterial vector vaccine is an attractive vaccination strategy to induce an immune response to a carried protective antigen. The superiorities of live bacterial vectors include mimicry of a natural infection, intrinsic adjuvant properties, and the potential for administration by mucosal routes. Escherichia coli is a simple and efficient vector system for production of exogenous proteins. In addition, many strains are nonpathogenic and avirulent, making it a good candidate for use in recombinant vaccine design. In this study, we screened 23 different iron-regulated promoters in an E. coli BL21(DE3) vector and found one, PviuB, with characteristics suitable for our use. We fused PviuB with lysis gene E, establishing an in vivo inducible lysis circuit. The resulting in vivo lysis circuit was introduced into a strain also carrying an IPTG (isopropyl-β-d-thiogalactopyranoside)-inducible PT7-controlled protein synthesis circuit, forming a novel E. coli-based protein delivery system. The recombinant E. coli produced a large amount of antigen in vitro and could deliver the antigen into zebrafish after vaccination via injection. The strain subsequently lysed in response to the iron-limiting signal in vivo, implementing antigen release and biological containment. The gapA gene, encoding the protective antigen GAPDH (glyceraldehyde-3-phosphate dehydrogenase) from the fish pathogen Aeromonas hydrophila LSA34, was introduced into the E. coli-based protein delivery system, and the resultant recombinant vector vaccine was evaluated in turbot (Scophtalmus maximus). Over 80% of the vaccinated fish survived challenge with A. hydrophila LSA34, suggesting that the E. coli-based antigen delivery system has great potential in bacterial vector vaccine applications