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Author (down) Garcin N, Viblanc VA, Schull Q, Michaux D, Reichert S, Robin JP, Bize P, Stier A
Title Naturally equipped to resist stress Type Peer-reviewed symposium
Year 2021 Publication Society for experimental biology annual conference. poster. actes du colloque Abbreviated Journal
Volume Issue Pages
Keywords
Abstract Stress exposure and stress response are likely to vary according to life history strategies and environmental contexts. Although the acute release of glucocorticoids in response to unpredictable environmental conditions may lead to adaptative behavioral and physiological responses, exposure to high glucocorticoid levels on the long-term usually leads to deleterious cascading effects on animal’s physiology, behavior and fitness. Yet, some species may be more adapted to cope with challenging events than others and might naturally possess protective mechanisms limiting the adverse consequences of prolonged exposure to high glucocorticoid levels. King penguin chicks being naturally exposed to harsh weather, prolonged fasting and constant predation pressure, we investigated the life-history, behavioral and physiological consequences of an experimental increase in corticosterone levels on the medium and long-term (after removing implants), predicting to find relatively few costs associated with such treatment. Although non-significant, CORT-treated chicks were slightly larger, fledged slightly earlier and had slightly higher survival chances than placebo chicks. CORT-treated chicks were significantly more aggressive and displayed lower corticosterone response to acute stress on the medium term, while their physical activity and whole-body energetics were not significantly affected. While mitochondrial density was not significantly affected by the CORT treatment, CORT-treated chicks had lower oxidative stress levels on the long-term than placebo ones, and no significant impact was observed on telomere shortening. Finally, the expression of several genes (i.e. CORT receptor, HSP90, mTOR, NRF2 and TERF2) was up regulated in treated chicks, which could potentially mediate the apparent ‘stress’ resistance we observed at the phenotypic level.
Programme 119
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Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes Approved yes
Call Number Serial 8454
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Author (down) G. J. Sutton, C. A. Bost, A. Z. Kouzani, S. D. Adams, K. Mitchell, J. P. Y. Arnould
Title Fine-scale foraging effort and efficiency of Macaroni penguins is influenced by prey type, patch density and temporal dynamics Type Journal
Year 2021 Publication Marine Biology Abbreviated Journal
Volume 168 Issue 1 Pages 3
Keywords
Abstract Difficulties quantifying in situ prey patch quality have limited our understanding of how marine predators respond to variation within and between patches, and throughout their foraging range. In the present study, animal-borne video, GPS, accelerometer and dive behaviour data loggers were used to investigate the fine-scale foraging behaviour of Macaroni penguins (Eudyptes chrysolophus) in response to prey type, patch density and temporal variation in diving behaviour. Individuals mainly dived during the day and utilised two strategies, targeting different prey types. Subantarctic krill (Euphausia vallentini) were consumed during deep dives, while small soft-bodied fish were captured on shallow dives or during the ascent phase of deep dives. Despite breeding in large colonies individuals seemed to be solitary foragers and did not engage with conspecifics in coordinated behaviour as seen in other group foraging penguin species. This potentially reflects the high abundance and low manoeuvrability of krill. Video data were used to validate prey capture signals in accelerometer data and a Support Vector Machine learning algorithm was developed to identify prey captures that occurred throughout the entire foraging trip. Prey capture rates indicated that Macaroni penguins continued to forage beyond the optimal give up time. However, bout-scale analysis revealed individuals terminated diving behaviour for reasons other than patch quality. These findings indicate that individuals make complex foraging decisions in relation to their proximate environment over multiple spatio-temporal scales.
Programme 394
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1432-1793 ISBN Medium
Area Expedition Conference
Notes Approved yes
Call Number Serial 2037
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Author (down) G. Hubert, S. Aubry
Title Study of the Impact of Past Extreme Solar Events on the Modern Air Traffic Type Journal
Year 2021 Publication Space Weather Abbreviated Journal
Volume 19 Issue 4 Pages e2020SW002665
Keywords
Abstract The ancient solar energetic particle (SEP) events of 774/775 CE and 993/994 CE were characterized thanks to radionuclide productions stored in environmental archives as ice cores or tree rings. Primary cosmic ray spectra deduced from these cosmogenic isotope data indicate that the impact of these extreme SEP events would have been much more significant than any of the ones observed during the modern era. However, the impact of these should be studied more accurately in the framework of the ambient dose equivalent impacting aircrew and passengers in the air traffic context by considering physical parameters such as time profile or anisotropy properties. In this study, the impact that 774/775 CE and 993/994 CE past extreme SEP events could have had on modern air traffic is discussed. Possible event spectra for these ancient events are derived from the spectra ground-level enhancement (GLE) 5 and GLE 69, which have been observed during the modern era and have been widely studied/characterized using measurements. The investigations include the impact of the SEP activity on ambient dose equivalent, including detailed analyses considering route, airplane characteristics (departure, arrival, continent, airplane type), and the time occurrence of the SEP event. Statistical analyses show that additional dose levels can reach values on the order of 70 mSv, which is absolutely significant considering the current air traffic recommendations. The orders of magnitude of the ambient dose equivalent induced during past extreme SEP events raises a number of issues, both for aircrews and for avionics hardware. This study demonstrates that simulations can be useful for the evaluation of risks in case of extreme SEP events.
Programme 1112
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1542-7390 ISBN Medium
Area Expedition Conference
Notes Approved yes
Call Number Serial 7934
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Author (down) G. Hubert, S. Aubry
Title Simulation of atmospheric cosmic-rays and their impacts based on pre-calculated databases, physical models and computational methods Type Journal
Year 2021 Publication Journal of Computational Science Abbreviated Journal
Volume 51 Issue Pages 101307
Keywords Ambient dose equivalent Atmospheric cosmic-rays Cosmogenic nuclide production Multi-physics Single event effect
Abstract The atmospheric cosmic-ray environment is composed of secondary particles produced when primary cosmic rays interact with the nucleus of atmospheric atoms. Modeling of atmospheric radiations is essential for investigating their impacts on human activities such as radiation risks in aviation or scientific fields such as cosmogenic dating. The nuclear transport codes are a common and accurate way to model the cosmic ray interaction in the atmosphere with minimal approximations. However, tracking all produced secondary particles in each event in the whole depth of the atmosphere and sampling many events to obtain the statistically meaningful results would be a computational challenge and disadvantageous from the point of view of time consumption. This paper presents a computational platform names ATMOS CORE based on pre-calculated databases coupled to physical models and computational methods. The fields of application concern the atmospheric cosmic-rays characterization as well as their effects on electronics systems, on the ambient dose for aircrews or the cosmogenic nuclide production for dating activities. Some comparisons between simulations and measurements are also presented and discussed.
Programme 1112
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1877-7503 ISBN Medium
Area Expedition Conference
Notes Approved yes
Call Number Serial 7957
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Author (down)
Title Theoretical and Experimental Analysis for Cleaning Ice Cores from EstisolTM 140 Drill Liquid Type Journal
Year 2021 Publication Applied Sciences Abbreviated Journal
Volume 11 Issue 9 Pages 3830
Keywords Beyond EPICA drilling Estisol ice cores
Abstract
Programme 1202
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes Approved yes
Call Number Serial 8247
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Author (down)
Title Spatial segregation in a sexually dimorphic central place forager: Competitive exclusion or niche divergence? Type Journal
Year 2021 Publication Journal of Animal Ecology Abbreviated Journal
Volume 90 Issue 10 Pages 2404-2420
Keywords bio-logging central place foraging ecological niche theory intraspecific competition kernel density estimates resource selection functions sexual segregation wandering albatross
Abstract
Programme 109,394
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Address
Corporate Author Thesis Bachelor's thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1365-2656 ISBN Medium
Area Expedition Conference
Notes Approved yes
Call Number Serial 8093
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Author (down)
Title Radar altimeter waveform simulations in Antarctica with the Snow Microwave Radiative Transfer Model (SMRT) Type Journal
Year 2021 Publication Remote Sensing of Environment Abbreviated Journal
Volume 263 Issue Pages 112534
Keywords Antarctic ice sheet Field measurements Modeling Radar altimetry Remote sensing SMRT Waveform
Abstract Radar altimeters are important tools to monitor the volume of the ice sheets. The penetration of radar waves in the snowpack is a major source of uncertainty to retrieve surface elevation. To correct this effect, a better understanding of the sensitivity of the radar waveforms to snow properties is needed. Here, we present an extension of the Snow Model Radiative Transfer (SMRT) to compute radar waveforms and conduct a series of simulations on the Antarctic ice sheet. SMRT is driven by snow and surface roughness properties measured over a large latitudinal range during two field campaigns on the Antarctic Plateau. These measurements show that the snowpack is rougher, denser, less stratified, warmer, and has smaller snow grains near the coast than on the central Plateau. These simulations are compared to satellite observations in the Ka, Ku, and S bands. SMRT reproduces the observed waveforms well. For all sites and all sensors, the main contribution comes from the surface echo. The echo from snow grains (volume scattering) represents up to 40% of the amplitude of the total waveform power in the Ka band, and less at the lower frequencies. The highest amplitude is observed on the central Plateau due to the combination of higher reflection from the surface, higher scattering by snow grains in the Ka and Ku bands, and higher inter-layer reflections in the S band. In the Ka band, the wave penetrates in the snowpack less deeply on the central Plateau than near the coast because of the strong scattering caused by the larger snow grains. The opposite is observed in the S band, the wave penetrates deeper on the central Plateau because of the lower absorption due to the lower snow temperatures. The elevation bias caused by wave penetration into the snowpack show a constant bias of 10 cm for all sites in the Ka band, and a bias of 11 cm, and 21 cm in the Ku band for sites close to the coast and the central Plateau, respectively. Now that SMRT is performing waveform simulations, further work will address how the snowpack properties affect the parameters retrieved by more advanced retracking algorithms such as ICE-2 for different snow cover surfaces.
Programme 1110
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0034-4257 ISBN Medium
Area Expedition Conference
Notes Approved yes
Call Number Serial 7997
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Author (down) Fabrice Genevois, Christophe Barbraud
Title Type Journal
Year 2021 Publication Polar Biology Abbreviated Journal
Volume 44 Issue 1 Pages 217-219
Keywords Antarctic Interspecific feeding Penguin
Abstract
Programme 109
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1432-2056 ISBN 1432-2056 Medium
Area Expedition Conference
Notes Approved yes
Call Number Serial 8324
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Author (down) F. Thibon, L. Weppe, N. Vigier, C. Churlaud, T. Lacoue-Labarthe, M. Metian, Y. Cherel, P. Bustamante
Title Large-scale survey of lithium concentrations in marine organisms Type Journal
Year 2021 Publication Science of The Total Environment Abbreviated Journal
Volume 751 Issue Pages 141453
Keywords Bio-reduction Bioaccumulation Biogeography Ecotoxicology Multiple correspondence analyses Trophic webs
Abstract
Programme 109
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Corporate Author Thesis
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Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
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ISSN ISBN 0048-9697 Medium
Area Expedition Conference
Notes Approved yes
Call Number Serial 7944
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Author (down)
Title Molecular response of a sub-antarctic population of the blue mussel (Mytilus edulis platensis) to a moderate thermal stress Type Journal
Year 2021 Publication Marine Environmental Research Abbreviated Journal
Volume 169 Issue Pages 105393
Keywords 2DE Abiotic stress Biomonitoring Gills Indicator species Kerguelen island Mytilus sp. qRT-PCR Temperature
Abstract
Programme 409
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0141-1136 ISBN Medium
Area Expedition Conference
Notes Approved yes
Call Number Serial 8256
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