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. (2011). Gastrointestinal helminths of King penguins (Aptenodytes patagonicus) at Crozet Archipelago
. Polar Biol., 34(8), 1249–1252.
Abstract: Communities of helminths are known to be related to feeding behaviors of hosts. While climate change and overfishing can impact food availability for Antarctic piscivorous predators, knowledge about infectious and parasitic diseases among Antarctic species is scarce or fragmentary. We studied the helminth community of King penguins ( Aptenodytes patagonicus ) from the Crozet Archipelago, the main breeding area of the species. Based on a sample of 41 individuals found freshly dead from predation or starvation, the gastrointestinal helminth community in King penguins was composed of 1 species of cestode ( Tetrabothrius wrighti ) and 2 species of nematodes ( Tetrameres wetzeli and Contracaecum heardi ). Cestodes formed the core of the helminth community (97.5% of worms collected) with a prevalence of infestation of 100% and a mean intensity of 178.6 worms per host. Sources of infestation and pathologies caused by these worms are also discussed.
Keywords: Biomedical and Life Sciences,
Programme: 119
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. (2012). Hormonal responses to extreme fasting in subantarctic fur seal (Arctocephalus tropicalis) pups
. Am. J. Physiol. Regul. Integr. Comp. Physiol., 302 (8 ), R929–R940 .
Abstract: Surviving prolonged fasting implies closely regulated alterations in fuel provisioning to meet metabolic requirements, while preserving homeostasis. Little is known, however, of the endocrine regulations governing such metabolic adaptations in naturally fasting free-ranging animals. The hormonal responses to natural prolonged fasting and how they correlate to the metabolic adaptations observed, were investigated in subantarctic fur seal (Arctocephalus tropicalis) pups, which, because of the intermittent pattern of maternal attendance, repeatedly endure exceptionally long fasting episodes throughout their development (13 mo). Phase I fasting was characterized by a dramatic decrease in plasma insulin, glucagon, leptin, and total l-thyroxine (T4) associated with reductions in mass-specific resting metabolic rate (RMR), plasma triglycerides, glycerol, and urea-to-creatine ratio, while nonesterified fatty acids (NEFA) and -OHB increased. In contrast, the metabolic steady-state of phase II fasting reached within 6 days was associated with minimal concentrations of insulin, glucagon, and leptin; unchanged cortisol and triiodothyronine (T3); and moderately increased T4. The early fall in insulin and leptin may mediate the shift to the strategy of energy conservation, protein sparing, and primary reliance on body lipids observed in response to the cessation of feeding. In contrast to the typical mammalian starvation response, nonelevated cortisol and minimal glucagon levels may contribute to body protein preservation and downregulation of catabolic pathways, in general. Furthermore, thyroid hormones may be involved in a process of energy conservation, independent of pups' nutritional state. These original hormonal settings might reflect an adaptation to the otariid repeated fasting pattern and emphasize the crucial importance of a tight physiological control over metabolism to survive extreme energetic constraints.
Programme: 109
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Fund F, Perosanz F, Testut L, Loyer S, . (2013). An Integer Precise Point Positioning technique for sea surface observations using a GPS buoy
. Adv Space Res, 51(8), 1311–1322.
Abstract: GPS data dedicated to sea surface observation are usually processed using differential techniques. Unfortunately, the precision of resulting kinematic positions is baseline-length dependent. So, high precision sea surface observations using differential GPS techniques are limited to coasts, lakes, and rivers. Recent improvements in GPS satellite products (orbits, clocks, and phase biases) make phase ambiguity fixing at the zero difference level achievable and opens up the observation of the sea surface without geographical constraints. This paper recalls the concept of the Integer Precise Point Positioning technique and discusses the precision of GPS buoy positioning. A sequential version of the GINS software has been implemented to achieve single epoch GPS positioning. We used 1 Hz data from a two week GPS campaign conducted in the Kerguelen Islands. A GPS buoy has been moored close to a radar gauge and 90 m away from a permanent GPS station. This infrastructure offers the opportunity to compare both kinematic Integer Precise Point Positioning and classical differential GPS positioning techniques to in situ radar gauge data. We found that Precise Point Positioning results are not significantly biased with respect to radar gauge data and that horizontal time series are consistent with differential processing at the sub-centimetre precision level. Nevertheless, standard deviations of height time series with respect to radar gauge data are typically [45] cm. The dominant driver for noise at this level is attributed to errors in tropospheric estimates which propagate into position solutions.
Keywords: GPS, Ambiguity fixing, Tropospheric delays, Buoy, Radar gauge,
Programme: 688
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. (2012). Hormonal responses to extreme fasting in subantarctic fur seal (Arctocephalus tropicalis) pups
. Am. J. Physiol. Regul. Integr. Comp. Physiol., 302 (8 ), R929–R940 .
Abstract: Surviving prolonged fasting implies closely regulated alterations in fuel provisioning to meet metabolic requirements, while preserving homeostasis. Little is known, however, of the endocrine regulations governing such metabolic adaptations in naturally fasting free-ranging animals. The hormonal responses to natural prolonged fasting and how they correlate to the metabolic adaptations observed, were investigated in subantarctic fur seal (Arctocephalus tropicalis) pups, which, because of the intermittent pattern of maternal attendance, repeatedly endure exceptionally long fasting episodes throughout their development (13 mo). Phase I fasting was characterized by a dramatic decrease in plasma insulin, glucagon, leptin, and total l-thyroxine (T4) associated with reductions in mass-specific resting metabolic rate (RMR), plasma triglycerides, glycerol, and urea-to-creatine ratio, while nonesterified fatty acids (NEFA) and -OHB increased. In contrast, the metabolic steady-state of phase II fasting reached within 6 days was associated with minimal concentrations of insulin, glucagon, and leptin; unchanged cortisol and triiodothyronine (T3); and moderately increased T4. The early fall in insulin and leptin may mediate the shift to the strategy of energy conservation, protein sparing, and primary reliance on body lipids observed in response to the cessation of feeding. In contrast to the typical mammalian starvation response, nonelevated cortisol and minimal glucagon levels may contribute to body protein preservation and downregulation of catabolic pathways, in general. Furthermore, thyroid hormones may be involved in a process of energy conservation, independent of pups' nutritional state. These original hormonal settings might reflect an adaptation to the otariid repeated fasting pattern and emphasize the crucial importance of a tight physiological control over metabolism to survive extreme energetic constraints.
Programme: 119
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. (2012). Foraging in the Darkness of the Southern Ocean: Influence of Bioluminescence on a Deep Diving Predator
. PLOS ONE, 7(8), e43565.
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. (2012). MARINE BIOLOGY, 159(8), 1843–1852.
Abstract: Knowledge of habitat use by top marine predators in response to environmental conditions is crucial in the current context of global changes occurring in the Southern Ocean. We examined the at-sea locations of male Ad,lie penguins (Pygoscelis adeliae) breeding at Dumont d'Urville during their first, long incubation trip. Compared with the chick-rearing period, penguins performed longer trips, going to oceanic waters as far as 320 km from the colony. We observed 3 strategies: (1) five individuals covered large distances to the north, targeting open-ocean areas and following the currents of two persistent eddies; (2) five individuals foraged to the north-west, close to the Antarctic shelf slope at the limit of the pack ice; and (3) three individuals covered much shorter distances (northwards or eastwards). The foraging range also seemed to be limited by the body condition of the penguins before their departure to sea.
Keywords: Freshwater & Marine Ecology, Marine & Freshwater Sciences, Microbiology, Oceanography, Zoology,
Programme: 1091
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. (2013). Is the Species Flock Concept Operational? The Antarctic Shelf Case
. 1932-6203, 8(8), e68787.
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Laparie M, Renault D, Lebouvier M, Delattre T, . (2013). Is dispersal promoted at the invasion front? Morphological analysis of a ground beetle invading the Kerguelen Islands, Merizodus soledadinus (Coleoptera, Carabidae)
. Biol. Invasions, 15(8), 1641–1648.
Keywords: Biological invasion, Body size evolution, Developmental Biology, Dispersal syndrome, Ecology, Freshwater & Marine Ecology, Insect, Invasion succession, Plant Sciences, Sub-Antarctic islands,
Programme: 136
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. (2013). A Space Oddity: Geographic and Specific Modulation of Migration in Eudyptes Penguins
. PLOS ONE, 8(8).
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. (2013). Two years of atmospheric boundary layer observations on a 45-m tower at Dome C on the Antarctic plateau
. J. Geophys. Res., 118(8), 3218–3232.
Keywords: 3307 Boundary layer processes, 3329 Mesoscale meteorology, 3349 Polar meteorology, 3394 Instruments and techniques, 9310 Antarctica, Antarctica, Boundary layer processes, Mesoscale meteorology, Polar meteorology,
Programme: 1013
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