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Adam T. Devlin, Jiayi Pan, Hui Lin. (2020). Multi-Timescale Analysis of Tidal Variability in the Indian Ocean Using Ensemble Empirical Mode Decomposition (Vol. 125).
Abstract: Ocean tides have been observed to be changing worldwide for nonastronomical reasons, which can combine with rising mean sea level (MSL) to increase the long-term impact to coastal regions. Tides can also exhibit variability at shorter timescales, which may be correlated with short-term variability in MSL. This short-term coupling may yield higher peak water levels and increased impacts of exceedance events that may be equally significant as long-term sea level rise. Previous studies employed the tidal anomaly correlation (TAC) method to quantify the sensitivity of tides to MSL fluctuations at long-period (>20 years) tide gauges in basin-scale surveys of the Pacific and Atlantic Ocean, finding that TACs exist at most locations. The Indian Ocean also experiences significant sea level rise and tidal variability yet has been less studied due to a sparse network of tide gauges. However, since the beginning of the 21st century, more tide gauges have been established in a wider geographical range, bringing the possibility of better estimates of tidal and MSL variability. Here, we improve the TAC approach, using the ensemble empirical mode decomposition (EEMD) method to analyze tidal amplitudes and sea level at multiple frequency bands, allowing a more effective use of shorter record tide gauges and better understanding of multiple timescales of tidal variability. We apply this approach to 73 tide gauges in the Indian Ocean to better quantify tidal variability in these under-studied regions, finding that the majority of locations exhibit significant correlations of tides and MSL.
Keywords: Coastal risks Ensemble Empirical Mode Decomposition Indian Ocean Sea level variability Tidal evolution Tidal variability
Programme: 688
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Adélie Antoine, Sara Labrousse, Pauline Goulet, Mathilde Chevallay, Joris Laborie, Baptiste Picard, Christophe Guinet, David Nerini, Jean-Benoît Charrassin, Karine Heerah. (2023). Beneath the Antarctic sea-ice: Fine-scale analysis of Weddell seal (Leptonychotes weddellii) behavior and predator–prey interactions, using micro-sonar data in Terre Adélie (Vol. 13).
Abstract: Lactation is the most energy-demanding event in mammals' reproduction. In pinnipeds, females are the only food providers to the young and have developed numerous behavioral and physiological lactation strategies, from capital-breeding to income-breeding. Lactating females' fine-scale foraging strategy, and precise understanding of how females supplement their pup's needs as well as their own are important to understand the species' ecology and energetic balance. Polar pinnipeds, inhabiting extreme environments, are sensitive to climate change and variability, understanding their constraints and foraging strategy during lactation is therefore important. In 2019, three sonar tags were deployed on lactating Weddell seals in Terre Adélie (East Antarctica) for 7 days, to study fine-scale predator–prey interactions. Feeding activity was mostly benthic, reduced, central-placed, and spatially limited. Females spent most of their time hauled-out. A total of 331 prey capture attempts (PrCAs) were recorded using triaxial acceleration data, with 125 prey identified on echograms (5 cm, acoustic size). All PrCAs occurred on the seafloor, shallower than usual records (mean depth of 88 m, vs 280 m after their molt). We also found that they only fed in three of the five identified dive shapes, during the ascent or throughout the dive. Half of the prey were reactive to the seal's approach, either leaving the seafloor, or escaping just above the seafloor, suggesting that the seals hunt by chasing them from the seabed. Seals continuously scanned the area during the approach phase, evoking opportunistic foraging. Our results provide additional evidence that Weddell seal forage during lactation, displaying a mix of capital-breeding and income-breeding strategies during this period of physiological stress. This work sheds light on previously unexplored aspects of their foraging behavior, such as shallow water environments, targeting benthic prey, generally focusing on single prey rather than schools, and evidence of visual scanning through observed head movements.
Keywords: bio-logging diving foraging behavior predator–prey interaction sonar tags Weddell seal
Programme: 1182
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Adnan Ghribi for the QUBIC Collaboration. (2013). QUBIC: The QU bolometric Interferometer for Cosmology.
Abstract: Contributed talk at LTD15 held in Pasadena, California, USA, June 24th-28th 2013
Programme: 915
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Adoutte A. & Philippe H. (1993). The major lines of metazoan evolution: summary of traditional evidence and lessons from ribosomal RNA sequence analysis..
Abstract: In Y. Pichon (Ed.) Invertebrate Molecular Neurobiology, Basel, Birkhäuser.
Programme: 195
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Adriane Cristina Mendes Prado, Mauricio Tizziani Pazianotto, Jose Manuel Quesada Molina, Miguel Antonio Cortes-Giraldo, Guillaume Hubert, Marlon Antonio Pereira, Claudio Antonio Federico. (2020). Simulation of Cosmic Radiation Transport Inside Aircraft for Safety Applications (Vol. 56).
Abstract: During the flight, an aircraft is submitted to a radiation environment composed of cosmic-ray-induced particles (CRIP) of which neutrons are responsible for approximately 40% of the crew effective dose and are the main cause of single event effects (SEE) in avionics systems at flight altitudes. A model of Learjet aircraft was developed on Monte Carlo simulation using the MCNPX code in order to detail the CRIP field inside the aircraft. The radiation source modeling was previously developed by a computational platform that simulates the energy and angular distributions of the CRIP along the atmosphere. In this article, we determined the variation of the neutron radiation field in several positions inside the aircraft at 11- and 18-km altitudes and for both equatorial and polar regions. The results suggest that the maximum variation of neutron fluence rate between different positions inside the aircraft shows a tendency of higher differences for a lower energy threshold (thermal and E > 1 MeV) in comparison with those differences for a higher energy threshold (E > 10 MeV). Moreover, the angular distribution results show relevant differences between positions inside aircraft, mainly for thermal neutrons close to the fuel. The general tendency is to enhance these discrepancies for devices with new technologies, due to their lower energy threshold for SEE occurrences.
Keywords: Aerospace electronics Aircraft Aircraft manufacture Aircraft simulation Atmospheric modeling Computational modeling cosmic radiation neutron fluence rate Neutrons safety single event effect
Programme: 1112
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Adrien Pajot, Alexandre Corbeau, Aurélie Jambon, Henri Weimerskirch. (2021). Diel at-sea activity of two species of great albatrosses: the ontogeny of foraging and movement behaviour (Vol. 52).
Abstract: The first year of life is a period of high mortality in animals. Reduced foraging capacities of naive individuals might be the primary cause of their mortality. These capacities are supposed to be progressively acquired during the first months of life. In this study, we investigate the ontogeny of flight capacities, by day and night, of first-year individuals, and compare it with adults from two closely related species of great albatrosses: Amsterdam Diomedea amsterdamensis and wandering Diomedea exulans albatrosses which forage in different environmental conditions. We used 71 tracks of 71 juvenile birds and 141 of 116 incubating adults to compare both age categories. In order to explore the effect of moon light on night activity, we elaborated a new formula which improves the precision of the proxy of moon illumination. By day, we found that juveniles of both species reach some adult foraging capacities in less than two months. By night, albatrosses have reduced activity increasing during the first weeks at sea for juveniles and changing in accordance with moon illumination for both juveniles and adults. A peak of flight activity at dawn and dusk was apparent for both species. Interspecific comparison underlined that Amsterdam albatrosses were more active than wandering albatrosses, suggesting a difference in food and foraging strategy. Overall, we highlighted how life history traits, environmental conditions and time of the day affect the foraging activity of two related species of seabirds.
Keywords: albatross diel activity pattern Diomedea flight behavior foraging activity moon illumination night activity seabirds
Programme: 109
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Aebischer, A., J. Lang, B. Sittler, and O. Gilg. (2014). Post-breeding movements as assessed via satellite telemetry of Greenlandic owls.
Abstract: 3rd International Snowy Owl Working Group. Russian Academy of Science, Oural Branch, Salekhard-Yamal, Russia, 2-6 March
Programme: 1036
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Aebischer, A., J. Lang, B. Sittler, and O. Gilg. (2014). Post-breeding movements as assessed via satellite telemetry of Greenlandic owls (2-6 March 2014). 3rd International Snowy Owl Working Group. Russian Academy of Science, Oural Branch, Salekhard-Yamal, Russia..
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Afonso E. (2004). Variabilité du cycle naturel de Toxoplasma gondii chez le chat domestique (Felis catus) : étude en populations naturelles..
Abstract: Rapport technique DEA ‘Analyse et modélisation des systèmes biologiques’ Lyon 1
Programme: 279
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Afonso E., Thulliez P., Pontier D., Gilot-Fromont E. (2007). Toxoplasmosis in prey species and consequences for prevalence in feral cats: not all preys are equal. Parasitology. Parasitology, 134, 1963–1971.
Abstract: Nous avons étudié l'infestation chez les chats capturés de 1994 à 2004 dans chaque site, et les anticorps IgG anti T.gondii ont été détectés dans le sérum en utilisant un test d'agglutination. La prévalence globale est égale à 51%. Malgré la faible densité de la population de chats, la transmission de la toxoplasmose est remarquablement efficace à Kerguelen comparativement aux chats de métropole: la plupart des individus séroconvertissent avant l'âge de trois ans. Comme attendu, la séroprévalence diffère entre les sites, selon le régime alimentaire et également selon le sexe, une fois pris en compte l'effet de l'âge. A Ratmanoff, où le lapin représente 50% des espèces retrouvées dans le régime alimentaire, les chats sont moins souvent infectés que dans les autres sites (Port-aux-français, Port Couvreux et Port Jeanne d'Arc où le lapin constitue plus de 90% du régime alimentaire) (Figure 1). Les mâles sont plus souvent infectés que les femelles et la différence entre sexes tend à être plus prononcée dans le site où un nombre plus important d'espèces de proies est disponible (Ratmanoff). Une différence dans l'efficacité de prédation entre mâles et femelles peut expliquer ce résultat. De façon générale, nos résultats suggèrent que la composition en proies influence le risque d'infectiondu chat à T. gondii. La composition en proies devrait donc être considérée comme un facteur majeur pour comprendre la dynamique d'infection de T. gondii.
Programme: 279
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