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Delille D., Marty G., Cansemi Soullard M. & Frankignoulle M. (1997). Influence of subantarctic Macrocystis bed metabolism in diel changes of marine bacterioplankton and CO2 fluxes. J. Plankton Res., 19(9), 1251–1264.
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Sarkissian A., Roscoe H.K., Fish D., Van Roozendael M., Gil M., Chen H.B., Wang P., Pommereau J.P. & Lenoble J. (1995). Ozone and NO2 air-mass factors for zenith-sky spectrometers: Intercomparison of calculations with different radiative transfer models. Geophysical research letters, 22(9), 1113–1116.
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. (2007). Tectonics and magma dynamics coupling in a dyke swarm of Iceland. Journal of structural geology, 29(9), 1477–1493.
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Van Petegem, F.,; Collins, T.,; Meuwis, M.-A.,; Gerday, C.,; Feller, G.,; Van Beeumen, J.,. (2002). Crystallization and preliminary X-ray analysis of a xylanase from the psychrophile Pseudoalteromonas haloplanktis. Acta Crystallogr. D Biol. Crystallogr., 58(9), 1494–1496.
Abstract: The 46 kDa xylanase from the Antarctic microorganism Pseudoalteromonas haloplanktis is an enzyme that efficiently catalyzes reactions at low temperatures. Here, the crystallization of both the native protein and the SeMet-substituted enzyme and data collection from both crystals using synchrotron radiation are described. The native data showed that the crystals diffract to 1.3 A resolution and belong to space group P212121, with unit-cell parameters a = 50.87, b = 90.51, c = 97.23 A. SAD data collected at the peak of the selenium absorption edge proved to be sufficient to determine the heavy-atom configuration and to obtain electron density of good quality.
Keywords: psychrophiles; cold-adapted enzyme; glycosyl hydrolases
Programme: 193
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. (2009). Limitation of population recovery: a stochastic approach to the case of the emperor penguin
. Oikos, 118(9), 1292–1298.
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Coco I, Amata E, Marcucci M F, Ambrosino D, Villain J-P, Hanuise C, . (2008). The effects of an interplanetary shock on the high-latitude ionospheric convection during an IMF By-dominated period
. Ann. Geophys., 26(9), 2937–2951.
Abstract: On 6 January 1998 an interplanetary shock hit the magnetosphere around 14:15 UT and caused a reconfiguration of the northern high-latitude ionospheric convection. We use SuperDARN, spacecraft and ground magnetometer data to study such reconfiguration. We find that the shock front was tilted towards the morning flank of the magnetosphere, while the Interplanetary Magnetic Field (IMF) was By-dominated, with By<0, IMF Bz>0 and |By|>>Bz. As expected, the magnetospheric compression started at the first impact point of the shock on the magnetopause causing an increase of the Chapman-Ferraro current from dawn to dusk and yielding an increase of the geomagnetic field at the geostationary orbit and on the ground. Moreover, the high-latitude magnetometer data show vortical structures clearly related to the interaction of the shock with the magnetosphere-ionosphere system. In this context, the SuperDARN convection maps show that at very high latitudes above the northern Cusp and in the morning sector, intense sunward convection fluxes appear, well correlated in time with the SI arrival, having a signature typical for Bz>0 dominated lobe reconnection. We suggest that in this case the dynamic pressure increase associated to the shock plays a role in favouring the setting up of a new lobe merging line albeit |By|>>Bz≥0.
Programme: 312;911
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Dobson F Stephen, Jouventin Pierre, . (2010). The trade-off of reproduction and survival in slow-breeding seabirds
. Can. J. Zool., 88(9), 889–899.
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. (2011). Integument coloration signals reproductive success, heterozygosity, and antioxidant levels in chick-rearing black-legged kittiwakes
. Naturwissenschaften, 98(9), 773–782.
Abstract: Carotenoid pigments are important for immunity and as antioxidants, and carotenoid-based colors are believed to provide honest signals of individual quality. Other colorless but more efficient antioxidants such as vitamins A and E may protect carotenoids from bleaching. Carotenoid-based colors have thus recently been suggested to reflect the concentration of such colorless antioxidants, but this has rarely been tested. Furthermore, although evidence is accruing for multiple genetic criteria for mate choice, carotenoid-based colors have rarely been shown to reflect both phenotypic and genetic quality. In this study, we investigated whether gape, tongue, eye-ring, and bill coloration of chick-rearing black-legged kittiwakes Rissa tridactyla reflected circulating levels of carotenoids and vitamins A and E. We further investigated whether integument coloration reflected phenotypic (body condition and fledging success) and genetic quality (heterozygosity). We found that the coloration of fleshy integuments was correlated with carotenoid and vitamin A levels and fledging success but only in males. Furthermore, the coloration of tongue and eye-ring was correlated with heterozygosity in both males and females. Integument colors might therefore be reliable signals of individual quality used by birds to adjust their parental care during the chick-rearing period.
Keywords: Biomedical and Life Sciences,
Programme: 1162
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. (2011). A large new species of the genus Ptilocrinus (Echinodermata, Crinoidea, Hyocrinidae) from Antarctic seamounts
. Polar Biol., 34(9), 1385–1397.
Abstract: Ptilocrinus amezianeae n. sp. is a new species of stalked crinoid attributed to the family Hyocrinidae. Forty-five specimens were collected from seamounts north of the Ross Sea, and one specimen from the Kerguelen Plateau at depths ranging from 450 to 1,680 m. The collection from Admiralty and Scott seamounts constitutes the first example of a hyocrinid population known both from in situ photographs and from numerous collected specimens ranging from small juvenile to large adult. Variation in theca and stalk articulation characters throughout ontogeny is congruent with the molecular data and indicates that all the specimens examined belong to a single species. Tegmen and pinnule architecture, brachial arrangement, and stalk articular facets indicate that Ptilocrinus amezianeae n. sp. has close affinities with P. clarki and P. pinnatus from the northeastern Pacific and displays the most derived characters among these three species. Two cases of true arm division into two unequal branches suggest that Ptilocrinus and Calamocrinus are closely related. The picture and video transects on Admiralty seamount show a patchy distribution of living specimens with patches of mean density ca. 2.6 individuals m-2. In situ photographs also document predation by a sea urchin and a sea star on tegmen and proximal arms. The COI gene sequences analyzed in 25 specimens from Admiralty and Scott seamounts display low pairwise distances, low nucleotidic diversity, and intermediate haplotype diversity. These results, together with disarticulated ossicles and attachment disks observed on in situ photographs, indicate that the population investigated here is in decline.
Keywords: Biomedical and Life Sciences,
Programme: 1124
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. (2011). Genetic structure of marine Borrelia garinii and population admixture with the terrestrial cycle of Lyme borreliosis
. Environ. Microbiol., 13(9), 2453–2467.
Abstract: Despite the importance of population structure for the epidemiology of pathogenic bacteria, the spatial and ecological heterogeneity of these populations is often poorly characterized. Here, we investigated the genetic diversity and population structure of the Lyme borreliosis (LB) spirochaete Borrelia garinii in its marine cycle involving colonial seabirds and different host races of the seabird tick Ixodes uriae. Multilocus sequence analyses (MLSA) on eight chromosomal and two plasmid loci (ospA and ospC) indicate that B. garinii circulating in the marine system is highly diverse. Microevolution in marine B. garinii seems to be mainly clonal, but recombination and selection do occur. Sequence types were not evenly distributed among geographic regions, with substantial population subdivision between Atlantic and Pacific Ocean basins. However, no geographic structuring was evident within regions. Results of selection analyses and phylogenetic discordance between chromosomal and plasmid loci indicate adaptive evolution is likely occurring in this system, but no pattern of host or vector-associated divergence was found. Recombination analyses showed evidence for population admixture between terrestrial and marine strains, suggesting that LB spirochaetes are exchanged between these enzootic cycles. Importantly, our results highlight the need to explicitly consider the marine system for a complete understanding of the evolutionary ecology and global epidemiology of Lyme borreliosis.
Programme: 333
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