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Author (up) Gustavo Yunda-Guarin, Thomas A. Brown, Loïc N. Michel, Blanche Saint-Béat, Rémi Amiraux, Christian Nozais, Philippe Archambault doi  openurl
  Title Reliance of deep-sea benthic macrofauna on ice-derived organic matter highlighted by multiple trophic markers during spring in Baffin Bay, Canadian Arctic Type Journal
  Year 2020 Publication Elementa: Science of the Anthropocene Abbreviated Journal  
  Volume 8 Issue 1 Pages  
  Keywords  
  Abstract Benthic organisms depend primarily on seasonal pulses of organic matter from primary producers. In the Arctic, declines in sea ice due to warming climate could lead to changes in this food supply with as yet unknown effects on benthic trophic dynamics. Benthic consumer diets and food web structure were studied in a seasonally ice-covered region of Baffin Bay during spring 2016 at stations ranging in depth from 199 to 2,111 m. We used a novel combination of highly branched isoprenoid (HBI) lipid biomarkers and stable isotope ratios (δ13C, δ15N) to better understand the relationship between the availability of carbon sources in spring on the seafloor and their assimilation and transfer within the benthic food web. Organic carbon from sea ice (sympagic carbon [SC]) was an important food source for benthic consumers. The lipid biomarker analyses revealed a high relative contribution of SC in sediments (mean SC% ± standard deviation [SD] = 86% ± 16.0, n = 17) and in benthic consumer tissues (mean SC% ± SD = 78% ± 19.7, n = 159). We also detected an effect of sea-ice concentration on the relative contribution of SC in sediment and in benthic consumers. Cluster analysis separated the study region into three different zones according to the relative proportions of SC assimilated by benthic macrofauna. We observed variation of the benthic food web between zones, with increases in the width of the ecological niche in zones with less sea-ice concentration, indicating greater diversity of carbon sources assimilated by consumers. In zones with greater sea-ice concentration, the higher availability of SC increased the ecological role that primary consumers play in driving a stronger transfer of nutrients to higher trophic levels. Based on our results, SC is an important energy source for Arctic deep-sea benthos in Baffin Bay, such that changes in spring sea-ice phenology could alter benthic food-web structure.  
  Programme 1164  
  Campaign  
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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 2325-1026 ISBN Medium  
  Area Expedition Conference  
  Notes Approved yes  
  Call Number Serial 8119  
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Author (up) Haberle, V. openurl 
  Title Automatic Characterisation of Magnetic Indices with Artificial Intelligence Type Master 2
  Year 2020 Publication Irap, Toulouse Abbreviated Journal  
  Volume Issue Pages  
  Keywords  
  Abstract  
  Programme 139  
  Campaign  
  Address  
  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 8098  
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Author (up) Hanane Marif, Jean Lilensten file  doi
openurl 
  Title Suprathermal electron moments in the ionosphere Type Journal
  Year 2020 Publication Journal of Space Weather and Space Climate Abbreviated Journal  
  Volume 10 Issue Pages 22  
  Keywords  
  Abstract The ionospheric electron population is divided into two groups. The ambient electrons are thermalized. Their energy is usually smaller than one electron volt. Their densities and temperatures are the usual ones measured by incoherent scatter radars, or modeled by international codes such as International Reference Ionosphere (IRI). There is however a second population called the suprathermal electrons. This one is either due to photoionization or to electron impact between the thermosphere and the precipitation in the high latitude zone. In the frame of space weather, it may be the source of scintillations, plasma bulks and other physical phenomena. The suprathermal electron population can only indirectly be measured through the plasmaline and had never been modeled. Its modeling requires the computation of the electron stationary flux by solving the Boltzmann transport equation. This flux is multiplied by various powers of the velocity v and integrated to obtain the different order moments. By integrating f over v0dv, one deduces the suprathermal electron density. An integration of v1fdv allows the computation of their mean velocity. Higher moments give access to their temperature and finally to their heat flux. In this work, we demonstrate for the first time the full and rigorous calculation of the ionospheric electron moments up to three. As two case studies, we focus on high latitude in the auroral oval and low magnetic latitude over Algiers for different solar and geophysical conditions. We compare the suprathermal densities and temperatures to the thermal electron parameters. Our results highlight that – as expected – the suprathermal density is small compared to the thermal one. Although it is close to 3 × 103 m−3 at 180 km during the day, it drops drastically at night, to hardly reach 3 m−3. Contrarily to the density, the velocity is about 10 times more important during the nighttime when precipitation occurs than during the daytime under the electromagnetic solar flux. At 400 km, it varies during the day between 700,000 m s−1 (active solar conditions) and 900,000 m s−1 (quiet Sun). At night, the velocity varies between 3 × 106 m s−1 (low mean energy precipitation) and 3 × 107 m s−1 (high mean energy precipitation) at 400 km. The suprathermal temperature increases as the solar activity decreases or as the mean energy of the electron precipitation increases. It may reach values close to 3 × 108 K. The heat flux may be fully oriented downward or experiences a reversal with some flux going up depending on the forcing.  
  Programme 1026  
  Campaign  
  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 2115-7251 ISBN Medium  
  Area Expedition Conference  
  Notes Approved yes  
  Call Number Serial 7679  
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Author (up) Hannah Joy Kriesell, Céline Le Bohec, Alexander F. Cerwenka, Moritz Hertel, Jean-Patrice Robin, Bernhard Ruthensteiner, Manfred Gahr, Thierry Aubin, Daniel Normen Düring file  doi
isbn  openurl
  Title Vocal tract anatomy of king penguins: morphological traits of two-voiced sound production Type Journal
  Year 2020 Publication Frontiers in Zoology Abbreviated Journal  
  Volume 17 Issue 1 Pages 5  
  Keywords  
  Abstract The astonishing variety of sounds that birds can produce has been the subject of many studies aiming to identify the underlying anatomical and physical mechanisms of sound production. An interesting feature of some bird vocalisations is the simultaneous production of two different frequencies. While most work has been focusing on songbirds, much less is known about dual-sound production in non-passerines, although their sound production organ, the syrinx, would technically allow many of them to produce “two voices”. Here, we focus on the king penguin, a colonial seabird whose calls consist of two fundamental frequency bands and their respective harmonics. The calls are produced during courtship and for partner and offspring reunions and encode the birds’ identity. We dissected, μCT-scanned and analysed the vocal tracts of six adult king penguins from Possession Island, Crozet Archipelago.  
  Programme 119,137  
  Campaign  
  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 1742-9994 ISBN 1742-9994 Medium  
  Area Expedition Conference  
  Notes Approved yes  
  Call Number Serial 7671  
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Author (up) Hanqin Tian, Rongting Xu, Josep G. Canadell, Rona L. Thompson, Wilfried Winiwarter, Parvadha Suntharalingam, Eric A. Davidson, Philippe Ciais, Robert B. Jackson, Greet Janssens-Maenhout, Michael J. Prather, Pierre Regnier, Naiqing Pan, Shufen Pan, Glen P. Peters, Hao Shi, Francesco N. Tubiello, Sönke Zaehle, Feng Zhou, Almut Arneth, Gianna Battaglia, Sarah Berthet, Laurent Bopp, Alexander F. Bouwman, Erik T. Buitenhuis, Jinfeng Chang, Martyn P. Chipperfield, Shree R. S. Dangal, Edward Dlugokencky, James W. Elkins, Bradley D. Eyre, Bojie Fu, Bradley Hall, Akihiko Ito, Fortunat Joos, Paul B. Krummel, Angela Landolfi, Goulven G. Laruelle, Ronny Lauerwald, Wei Li, Sebastian Lienert, Taylor Maavara, Michael MacLeod, Dylan B. Millet, Stefan Olin, Prabir K. Patra, Ronald G. Prinn, Peter A. Raymond, Daniel J. Ruiz, Guido R. van der Werf, Nicolas Vuichard, Junjie Wang, Ray F. Weiss, Kelley C. Wells, Chris Wilson, Jia Yang, Yuanzhi Yao doi  isbn
openurl 
  Title A comprehensive quantification of global nitrous oxide sources and sinks Type Journal
  Year 2020 Publication Nature Abbreviated Journal  
  Volume 586 Issue 7828 Pages 248-256  
  Keywords  
  Abstract Nitrous oxide (N2O), like carbon dioxide, is a long-lived greenhouse gas that accumulates in the atmosphere. Over the past 150 years, increasing atmospheric N2O concentrations have contributed to stratospheric ozone depletion1 and climate change2, with the current rate of increase estimated at 2 per cent per decade. Existing national inventories do not provide a full picture of N2O emissions, owing to their omission of natural sources and limitations in methodology for attributing anthropogenic sources. Here we present a global N2O inventory that incorporates both natural and anthropogenic sources and accounts for the interaction between nitrogen additions and the biochemical processes that control N2O emissions. We use bottom-up (inventory, statistical extrapolation of flux measurements, process-based land and ocean modelling) and top-down (atmospheric inversion) approaches to provide a comprehensive quantification of global N2O sources and sinks resulting from 21 natural and human sectors between 1980 and 2016. Global N2O emissions were 17.0 (minimum–maximum estimates: 12.2–23.5) teragrams of nitrogen per year (bottom-up) and 16.9 (15.9–17.7) teragrams of nitrogen per year (top-down) between 2007 and 2016. Global human-induced emissions, which are dominated by nitrogen additions to croplands, increased by 30% over the past four decades to 7.3 (4.2–11.4) teragrams of nitrogen per year. This increase was mainly responsible for the growth in the atmospheric burden. Our findings point to growing N2O emissions in emerging economies—particularly Brazil, China and India. Analysis of process-based model estimates reveals an emerging N2O–climate feedback resulting from interactions between nitrogen additions and climate change. The recent growth in N2O emissions exceeds some of the highest projected emission scenarios3,4, underscoring the urgency to mitigate N2O emissions.  
  Programme 416  
  Campaign  
  Address  
  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 1476-4687 ISBN 1476-4687 Medium  
  Area Expedition Conference  
  Notes Approved yes  
  Call Number Serial 7968  
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Author (up) Helle A. Pedersen, Nicolas Leroy, Dimitri Zigone, Martin Vallée, Adam T. Ringler, David C. Wilson doi  openurl
  Title Using Component Ratios to Detect Metadata and Instrument Problems of Seismic Stations: Examples from 18 Yr of GEOSCOPE Data Type Journal
  Year 2020 Publication Seismological research letters Abbreviated Journal  
  Volume 91 Issue 1 Pages 272-286  
  Keywords  
  Abstract Replacement or deterioration of seismic instruments and the evolution of the installation conditions and sites can alter the seismic signal in very subtle ways; therefore, it is notoriously difficult to monitor the signal quality of permanent seismic stations. We present a simple way to characterize and monitor signal quality, using energy ratios between each pair of the three components, as a complement to existing methods. To calculate stable daily energy ratios over a large frequency range (0.01–5 Hz), we use the daily median energy ratio over all 5 min windows within the day. The method is applied to all GEOSCOPE stations, for continuous BH channel data collected since 2001. We show applications to identify past gain problems (stations ROCAM and CRZF), to provide feedback after field interventions at remote sites (Antarctic station DRV), and to shed light on complex instrument problems (stations ECH and KIP). Our results show that component energy ratios have excellent time resolution and that they are visually simple for identification of problems. They can be used both for ongoing continuous monitoring of the signal quality, or as a tool to identify past problems. The Python code to produce the results in this work and the Python code for daily monitoring used by GEOSCOPE are available (see Data and Resources).  
  Programme 133  
  Campaign  
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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 7672  
Permanent link to this record
 

 
Author (up) Héloïse Barbel, Dominique Todisco, Najat Bhiry file  doi
openurl 
  Title A geochemical investigation of an Early Inuit semi-subterranean winter dwelling in a periglacial context Type Journal
  Year 2020 Publication Journal of archaeological science: reports Abbreviated Journal  
  Volume 33 Issue Pages 102552  
  Keywords C-N analysis Cryosolic soils geochemistry FTIR ICP-AES Inuit archaeology Nunavik Semi-subterranean house  
  Abstract Geochemical investigations using FTIR, ICP-AES and C-N analyses were carried out on a single-family semi-subterranean Inuit house in order to assess the contribution of Inuit domestic activities in the formation of cryosolic soils in a periglacial archaeological context (Kuuvik Bay, Nunavik, Canada). The geochemical elements data were analyzed using box plots and enrichment factors. The information was also summarized and visualized through principal component analysis (PCA). These complementary statistical approaches provided evidence of a moderate but identifiable and significant imprint of Inuit domestic activities on soil geochemistry. The box plots indicate moderate Ca, Mn, Cu and P enrichments and more noticeable Mg, Fe and S enrichments. These enrichment factors and the ICP-AES data show that samples from the peripheral wall and the tunnel entrance of the house and its vicinity are significantly enriched. While FTIR analysis highlighted the main soil element contents (e.g., organic and mineral components), ICP-AES analysis was used to further document variations in the background elements throughout the site. However, the obtained results do not allow us to undertake a spatial analysis of Inuit activities or to describe them in detail. In addition, the data highlight the difficulty of documenting the natural variability of element contents in cryosolic soils, especially in archaeological contexts. Cryo-pedological processes in the active layer as well as house cleaning and nutrient inputs resulting from Inuit occupations may have attenuated chemical signatures of previous Inuit domestic activities.  
  Programme 1080  
  Campaign LOTECHAIN  
  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 2352-409X ISBN Medium  
  Area Expedition Conference  
  Notes Approved yes  
  Call Number Serial 8206  
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Author (up) Henri Weimerskirch, Julien Collet, Alexandre Corbeau, Adrien Pajot, Floran Hoarau, Cédric Marteau, Dominique Filippi, Samantha C. Patrick doi  openurl
  Title Ocean sentinel albatrosses locate illegal vessels and provide the first estimate of the extent of nondeclared fishing Type Journal
  Year 2020 Publication Proceedings of the National Academy of Sciences Abbreviated Journal  
  Volume 117 Issue 6 Pages 3006-3014  
  Keywords bio-logging conservation illegal fisheries seabird vessel attraction  
  Abstract With threats to nature becoming increasingly prominent, in order for biodiversity levels to persist, there is a critical need to improve implementation of conservation measures. In the oceans, the surveillance of fisheries is complex and inadequate, such that quantifying and locating nondeclared and illegal fisheries is persistently problematic. Given that these activities dramatically impact oceanic ecosystems, through overexploitation of fish stocks and bycatch of threatened species, innovative ways to monitor the oceans are urgently required. Here, we describe a concept of “Ocean Sentinel” using animals equipped with state-of-the-art loggers which monitor fisheries in remote areas. Albatrosses fitted with loggers detecting and locating the presence of vessels and transmitting the information immediately to authorities allowed an estimation of the proportion of nondeclared fishing vessels operating in national and international waters of the Southern Ocean. We found that in international waters, more than one-third of vessels had no Automatic Identification System operating; in national Exclusive Economic Zones (EEZs), this proportion was lower on average, but variable according to EEZ. Ocean Sentinel was also able to provide unpreceded information on the attraction of seabirds to vessels, giving access to crucial information for risk-assessment plans of threatened species. Attraction differed between species, age, and vessel activity. Fishing vessels attracted more birds than other vessels, and juveniles both encountered fewer vessels and showed a lower attraction to vessels than adults. This study shows that the development of technologies offers the potential of implementing conservation policies by using wide-ranging seabirds to patrol oceans.  
  Programme 109  
  Campaign  
  Address  
  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 0027-8424, 1091-6490 ISBN Medium  
  Area Expedition Conference  
  Notes Approved yes  
  Call Number Serial 7684  
Permanent link to this record
 

 
Author (up) Herlédan M., Delattre M., Masson E., Régnier S., Armynot Du Châtelet E. openurl 
  Title Les environnements des Kerguelen : étude des amibes à thèque et des caractéristiques géochimiques Type Peer-reviewed symposium
  Year 2020 Publication 16émes journées scientifiques du cnfra, 22-23 septembre 2020, la rochelle, france Abbreviated Journal  
  Volume Issue Pages  
  Keywords  
  Abstract  
  Programme 1200  
  Campaign  
  Address  
  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 8054  
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Author (up) Hila Levy, Steven R Fiddaman, Juliana A Vianna, Daly Noll, Gemma V Clucas, Jasmine K H Sidhu, Michael J Polito, Charles A Bost, Richard A Phillips, Sarah Crofts, Gary D Miller, Pierre Pistorius, Francesco Bonnadonna, Céline Le Bohec, Andrés Barbosa, Phil Trathan, Andrea Raya Rey, Laurent A F Frantz, Tom Hart, Adrian L Smit file  doi
openurl 
  Title Evidence of Pathogen-Induced Immunogenetic Selection across the Large Geographic Range of a Wild Seabird Type Journal
  Year 2020 Publication Molecular Biology and Evolution Abbreviated Journal  
  Volume 37 Issue 6 Pages 1708-1726  
  Keywords immunogenetics, positive selection, Toll-like receptors, pathogen-mediated selection, Antarctica and Southern Ocean, Gentoo penguin  
  Abstract Over evolutionary time, pathogen challenge shapes the immune phenotype of the host to better respond to an incipient threat. The extent and direction of this selection pressure depend on the local pathogen composition, which is in turn determined by biotic and abiotic features of the environment. However, little is known about adaptation to local pathogen threats in wild animals. The Gentoo penguin (Pygoscelis papua) is a species complex that lends itself to the study of immune adaptation because of its circumpolar distribution over a large latitudinal range, with little or no admixture between different clades. In this study, we examine the diversity in a key family of innate immune genes—the Toll-like receptors (TLRs)—across the range of the Gentoo penguin. The three TLRs that we investigated present varying levels of diversity, with TLR4 and TLR5 greatly exceeding the diversity of TLR7. We present evidence of positive selection in TLR4 and TLR5, which points to pathogen-driven adaptation to the local pathogen milieu. Finally, we demonstrate that two positively selected cosegregating sites in TLR5 are sufficient to alter the responsiveness of the receptor to its bacterial ligand, flagellin. Taken together, these results suggest that Gentoo penguins have experienced distinct pathogen-driven selection pressures in different environments, which may be important given the role of the Gentoo penguin as a sentinel species in some of the world’s most rapidly changing environments.  
  Programme 137,354  
  Campaign  
  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 0737-4038 ISBN Medium  
  Area Expedition Conference  
  Notes Approved yes  
  Call Number Serial 7663  
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