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Author Christophe Barbraud, Dominique Joubert, Karine Delord
Title The demography of the White-headed Petrel at Mayes Island, Kerguelen Type Journal
Year (down) 2023 Publication Journal of Ornithology Abbreviated Journal
Volume Issue Pages
Keywords Adult survival Breeding Capture-mark-recapture Population growth rate Pterodroma lessonii Seabird
Abstract The demography and factors affecting the population dynamics of gadfly petrels (Pterodroma spp.) remain poorly known, although they constitute the most diverse genus of Procellariiformes and many species are threaten. Using a long-term individual monitoring dataset over 35 years, this study provides estimates of state-specific demographic parameters of the White-headed Petrel (Pterodroma lessonii) from Mayes Island, Kerguelen archipelago, and tests for the effects of environmental factors. Age at first breeding was 8.7 ± 2.6 years and apparent adult annual survival was 0.941 ± 0.058. Annual breeding probability was 0.356 ± 0.036 for successful breeders and 0.988 ± 0.054 for individuals that took a sabbatical year after a successful breeding event. Successful breeders that bred during two consecutive years had a lower breeding success (0.574 ± 0.048) that individuals that bred after a sabbatical year (0.655 ± 0.036). The realized population growth rate (1.073 ± 0.011) suggested that the population is increasing. There was a slight evidence for a positive effect of the Southern Annular Mode on the breeding probability of successful breeders, but no effect of sea surface temperature, chlorophyll a or wind was detected on demographic parameters. This study revealed that White-headed Petrels had a particularly high adult survival coherent with a quasi-biennial strategy and late age at first breeding. According to life history theory, populations of White-headed Petrel are thus likely to be very sensitive to small variations in adult survival, and anthropogenic factors causing additive mortality such as introduced predators will constitute serious threats for this species.
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 2193-7206 ISBN Medium
Area Expedition Conference
Notes Approved yes
Call Number Serial 8554
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Author Christophe Leroy-Dos Santos, Elise Fourré, Cécile Agosta, Mathieu Casado, Alexandre Cauquoin, Martin Werner, Benedicte Minster, Frederic Prié, Olivier Jossoud, Leila Petit, Amaëlle Landais
Title From atmospheric water isotopes measurement to firn core interpretation in Adelie Land: A case study for isotope-enabled atmospheric models in Antarctica Type Journal
Year (down) 2023 Publication EGUsphere Abbreviated Journal
Volume Issue Pages 1-20
Keywords
Abstract

Abstract. In a context of global warming and sea level rise acceleration, it is key to estimate the evolution of the atmospheric hydrological cycle and temperature in the polar regions, which directly influence the surface mass balance of the Arctic and Antarctic ice sheets. Direct observations are available from satellite data for the last 40 years and a few weather data since the 50’s in Antarctica. One of the best ways to access longer records is to use climate proxies in firn or ice cores. The water isotopic composition in these cores is widely used to reconstruct past temperature variations.

In order to progress in our understanding of the influence of the atmospheric hydrological cycle on the water isotopic composition, we first present a 2-year long time series of vapor and precipitation isotopic composition measurement at Dumont d’Urville station, in Adélie Land. We characterize diurnal variations of meteorological parameters (temperature, humidity and δ18O) for the different seasons and to determine the evolution of key relationships (δ18O versus temperature or humidity) along the year: we found mean annual slopes of 0.5 and 0.4 ‰ °C−1 for the relationship of δ18O vs. temperature in the water vapor and in the precipitation respectively. Then, this data set is used to evaluate the Atmospheric General Circulation Model ECHAM6-wiso (model version with embedded water stable isotopes) in a region where local conditions are controlled by strong katabatic winds which directly impact the isotopic signal. We show that a combination of continental (79 %) and oceanic (21 %) grid cells leads model outputs (temperature, humidity and δ18O) to nicely fit the observations, even winter extreme synoptic events are represented in the model. Therefore we demonstrate the added value of long-term water vapor isotopic composition records. Then, as a clear link is found between water vapor and precipitation isotopic composition, we evaluate how isotopic enabled models can help interpreting short firn cores.

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 ISBN Medium
Area Expedition Conference
Notes Approved yes
Call Number Serial 8629
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Author Christophe Leroy-Dos Santos, Elise Fourré, Cécile Agosta, Mathieu Casado, Alexandre Cauquoin, Martin Werner, Benedicte Minster, Frédéric Prié, Olivier Jossoud, Leila Petit, Amaëlle Landais
Title From atmospheric water isotopes measurement to firn core interpretation in Adélie Land: a case study for isotope-enabled atmospheric models in Antarctica Type Journal
Year (down) 2023 Publication The Cryosphere Abbreviated Journal
Volume 17 Issue 12 Pages 5241-5254
Keywords
Abstract In a context of global warming and sea level rise acceleration, it is key to estimate the evolution of the atmospheric hydrological cycle and temperature in polar regions, which directly influence the surface mass balance of the Arctic and Antarctic ice sheets. Direct observations are available from satellite data for the last 40 years and a few weather data since the 1950s in Antarctica. One of the best ways to access longer records is to use climate proxies in firn or ice cores. The water isotopic composition in these cores is widely used to reconstruct past temperature variations. We need to progress in our understanding of the influence of the atmospheric hydrological cycle on the water isotopic composition of ice cores. First, we present a 2-year-long time series of vapor and precipitation isotopic composition measurement at Dumont d’Urville Station, in Adélie Land. We characterize diurnal variations of meteorological parameters (temperature, atmospheric water mixing ratio (hereafter humidity) and δ18O) for the different seasons and determine the evolution of key relationships (δ18O versus temperature or humidity) throughout the year: we find that the temperature vs. δ18O relationship is dependent on synoptic events dynamics in winter contrary to summer. Then, this data set is used to evaluate the atmospheric general circulation model ECHAM6-wiso (model version with embedded water stable isotopes) in a coastal region of Adélie Land where local conditions are controlled by strong katabatic winds which directly impact the isotopic signal. We show that a combination of continental (79 %) and oceanic (21 %) grid cells leads model outputs (temperature, humidity and δ18O) to nicely fit the observations, at different timescales (i.e., seasonal to synoptic). Therefore we demonstrate the added value of long-term water vapor isotopic composition records for model evaluation. Then, as a clear link is found between the isotopic composition of water vapor and precipitation, we assess how isotopic models can help interpret short firn cores. In fact, a virtual firn core built from ECHAM-wiso outputs explains much more of the variability observed in S1C1 isotopic record than a virtual firn core built from temperature only. Yet, deposition and post-deposition effects strongly affect the firn isotopic signal and probably account for most of the remaining misfits between archived firn signal and virtual firn core based on atmospheric modeling.
Programme 1110,1205
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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 1994-0416 ISBN Medium
Area Expedition Conference
Notes Approved yes
Call Number Serial 8699
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Author Christophe Sauser, Karine Delord, Christophe Barbraud
Title Demography of cape petrels in response to environmental changes Type Journal
Year (down) 2023 Publication Population Ecology Abbreviated Journal
Volume 65 Issue 1 Pages 25-37
Keywords cape petrel capture–mark–recapture population dynamics sea surface temperature southern annular mode
Abstract Predicting the responses of populations in changing environments is an important task for ecologists. Understanding the population dynamics of high-latitude breeding species is critical given the particularly rapid environmental changes that occur in these regions. Using long-term mark–resighting data acquired over 53-years in Pointe Géologie, Terre Adélie, Antarctica, we estimated age-specific demographic parameters and evaluated the effect of the environment on survival of a poorly known species, the cape petrel Daption capense. We then modeled the dynamics of this population using a life-history model and performed prospective and retrospective analyses to estimate the sensitivity of the population growth rate to demographic parameters, and to quantify their relative contribution. Survival of cape petrel increased with age, being 0.610 (±0.193) for juveniles, 0.739 (±0.158) for individuals from 2 to 4, and 0.920 (±0.031) for older individuals. Minimum age at first reproduction was 3 years old, the age at which all birds were recruited was 14 years, and mean age at first reproduction was 9.05 (±2.06) years. Adult survival increased over time and was positively correlated with the southern annular mode (SAM). The stochastic population growth rate was estimated at 1.019, and adult survival over age 5 made the largest contribution to variance of the population growth rate. Sensitivity analyses revealed that population regulation was mainly driven by the SAM. Our results suggest that despite the decrease in breeding success, the population of cape petrels at Pointe Géologie increased due to the increase in immature and adult survival.
Programme 109
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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 1438-390X ISBN Medium
Area Expedition Conference
Notes Approved yes
Call Number Serial 8626
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Author Christopher Hoang, Olivier Magand, Jérôme Brioude, Andrea Dimuro, Christophe Brunet, Claudine Ah-Peng, Yann Bertrand, Aurelien Dommergue, Ying Duan Lei, Frank Wania
Title Probing the limits of sampling gaseous elemental mercury passively in the remote atmosphere Type Journal
Year (down) 2023 Publication Environmental Science: Atmospheres Abbreviated Journal
Volume 3 Issue 2 Pages 268-281
Keywords
Abstract Reliably recording very low ambient concentrations of gaseous elemental mercury (GEM) in remote regions is often required, for example in the context of evaluating how effective the Minamata Convention is in reducing global Hg emissions. However, sampling over extended periods of time at sites that are difficult to access can be very challenging. In order to establish what role inexpensive and easy-to-use passive air samplers may play in this regard, we deployed a sampler using a Radiello diffusive barrier and activated carbon sorbent for periods of up to three years and with sampling periods ranging from one to three months in some of the most extreme, remote and challenging global environments: at Concordia station on the Antarctic plateau, on Amsterdam Island in the remote Southern Indian Ocean and at several sites on the tropical island of La Réunion. The ability to reliably record the GEM concentrations at these sites was strongly influenced by the size of the sequestered amount of mercury relative to the extent and variability of the contamination of field blank samples. In some cases, acceptably low and consistent field blank contamination could only be achieved by storing samplers in sealed glass jars during transport and storage. The size of the sequestered amount is easily increased by extending deployment times, and the experience of the current study suggests that deployment periods in excess of two months are advisable. Sampling in Antarctica was compromised by the extreme low temperatures, which caused unknown sampling rates, hoar frost accumulation, material failure and potential failure of storage seals. While good agreement with GEM concentrations measured with an active sampler was noted on Amsterdam Island, the passive sampler derived levels at the Maïdo Observatory in La Réunion were notably higher than concentrations measured simultaneously with a Tekran vapour analyzer, which was possibly related to sampling rates being temporarily elevated at the very beginning of deployment at low GEM concentrations.
Programme 1028
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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 2634-3606 ISBN Medium
Area Expedition Conference
Notes Approved yes
Call Number Serial 8636
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Author Chuxian Li, Maxime Enrico, Oliver Magand, Beatriz F. Araujo, Gaël Le Roux, Stefan Osterwalder, Aurélien Dommergue, Yann Bertrand, Jérôme Brioude, François De Vleeschouwer, Jeroen E. Sonke
Title A peat core Hg stable isotope reconstruction of Holocene atmospheric Hg deposition at Amsterdam Island (37.8oS) Type Journal
Year (down) 2023 Publication Geochimica et Cosmochimica Acta Abbreviated Journal
Volume 341 Issue Pages 62-74
Keywords Hg deposition Hg stable isotopes Peat Rain Southern Hemisphere
Abstract Mercury (Hg) stable isotopes have been broadly used to investigate the sources, transformation and deposition of atmospheric Hg during the industrial era thanks to the multiple isotope signatures deriving from mass-dependent (represented by δ202Hg) and mass-independent fractionation (represented by ΔxxxHg) in the environment. Less is known about the impact of past climate change on atmospheric Hg deposition and cycling, and whether Hg isotopes covary with past climate. Here, we investigate Hg concentration and Hg isotope signatures in a 6600-year-old ombrotrophic peat record from Amsterdam Island (AMS, 37.8oS), and in modern AMS rainfall and gaseous elemental Hg (Hg0) samples. Results show that Holocene atmospheric Hg deposition and plant Hg uptake covary with dust deposition, and are both lower under a high humidity regime associated with enhanced Southern Westerly Winds. Modern AMS gaseous Hg0 and rainfall HgII isotope signatures are similar to those in the Northern Hemisphere (NH). Holocene peat Δ199Hg and Δ200Hg are significantly correlated (R2 = 0.67, P < 0.001, n = 58), consistently oscillating between the modern Hg0 and rainfall HgII end-members. Peat Δ200Hg and Δ199Hg provide evidence of plant uptake of Hg0 as the dominant pathway of Hg deposition to AMS peatland, with some exceptions during humid periods. In contrast to NH archives generally documenting a modern increase in Δ199Hg, recent peat layers (post-1900CE) from AMS show the lowest Δ199Hg in the peat profile (−0.42 ± 0.27 ‰, 1σ, n = 8). This likely reflects a significant change in the post-depositional process on deposited anthropogenic Hg in 20th century (i.e. dark abiotic reduction), enabling more negative Δ199Hg to be observed in AMS peat. We further find that the oscillations of Hg isotopes are consistent with established Holocene climate variability from dust proxies. We suggest peat Hg isotope records might be a valid rainfall indicator.
Programme 1028
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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 0016-7037 ISBN Medium
Area Expedition Conference
Notes Approved yes
Call Number Serial 8527
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Author Clive R. McMahon, Mark A. Hindell, Jean Benoit Charrassin, Richard Coleman, Christophe Guinet, Robert Harcourt, Sara Labrousse, Benjemin Raymond, Michael Sumner, Natalia Ribeiro
Title Southern Ocean pinnipeds provide bathymetric insights on the East Antarctic continental shelf Type Journal
Year (down) 2023 Publication Communications Earth & Environment Abbreviated Journal
Volume 4 Issue 1 Pages 1-10
Keywords Environmental sciences Ocean sciences
Abstract Poor coverage of the Antarctic continental shelf bathymetry impedes understanding the oceanographic processes affecting Antarctica’s role in global climate. Continental shelf bathymetry influences warm modified Circumpolar Deep Water movement onto the shelf, making it an important factor promoting ice shelf melting and influencing the flow of ice shelves into the ocean. Building on previous work using seal dives to redefine bathymetry, our longitudinal study of ocean physics and animal behaviour provided new depth information from over 500,000 individual seal dives on the East Antarctic continental shelf. About 25% of these seal dives were 220 m (sometimes over 1000 m) deeper than the interpolated seafloor from IBCSO V2. Focusing on four well-sampled regions, we show that the bathymetry of 22% to 60% of the sampled area was improved by incorporating seal dive data. This revealed new bathymetric features, including troughs off the Shackleton Ice Shelf and Underwood Glacier and a deep canyon near the Vanderford Glacier. This deep canyon, the Mirounga-Nuyina Canyon, was confirmed by a recent multi-beam echo sounder survey. Further acquisitions of seal data will improve our understanding and modelling of Antarctic coastal ocean processes and ice-sheet dynamics.
Programme 1201
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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 2662-4435 ISBN Medium
Area Expedition Conference
Notes Approved yes
Call Number Serial 8774
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Author Coline Marciau, David Costantini, Sophie Bestley, Olivia Hicks, Mark A. Hindell, Akiko Kato, Thierry Raclot, Cécile Ribout, Yan Ropert-Coudert, Frederic Angelier
Title Environmental Drivers of Growth and Oxidative Status during Early Life in a Long-Lived Antarctic Seabird, the Adélie Penguin Type Journal
Year (down) 2023 Publication Physiological and biochemical zoology: PBZ Abbreviated Journal
Volume 96 Issue 3 Pages 177-191
Keywords Adélie penguin Animals Antarctic Regions brood competition brood size early life hatching order oxidative stress Oxidative Stress protein carbonyls reactive oxygen metabolites Spheniscidae
Abstract AbstractIn vertebrates, developmental conditions can have long-term effects on individual performance. It is increasingly recognized that oxidative stress could be one physiological mechanism connecting early-life experience to adult phenotype. Accordingly, markers of oxidative status could be useful for assessing the developmental constraints encountered by offspring. Although some studies have demonstrated that developmental constraints are associated with high levels of oxidative stress in offspring, it remains unclear how growth, parental behavior, and brood competition may altogether affect oxidative stress in long-lived species in the wild. Here, we investigated this question in a long-lived Antarctic bird species by testing the impact of brood competition (e.g., brood size and hatching order) on body mass and on two markers of oxidative damage in Adélie penguin chicks. We also examined the influence of parental effort (i.e., foraging trip duration) and parental body condition on chick body mass and oxidative damage. First, we found that brood competition and parental traits had significant impacts on chick body mass. Second, we found that chick age and, to a lesser extent, chick body mass were two strong determinants of the levels of oxidative damage in Adélie penguin chicks. Finally, and importantly, we also found that brood competition significantly increased the levels of one marker of oxidative damage and was associated with a lower survival probability. However, parental effort and parental condition were not significantly linked to chick levels of oxidative damage. Overall, our study demonstrates that sibling competition can generate an oxidative cost even for this long-lived Antarctic species with a limited brood size (maximum of two chicks).
Programme 1091
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Corporate Author Thesis
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Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1537-5293 ISBN Medium
Area Expedition Conference
Notes Approved yes
Call Number Serial 8766
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Author Coline Marciau, Thierry Raclot, Sophie Bestley, Christophe Barbraud, Karine Delord, Mark Andrew Hindell, Akiko Kato, Charline Parenteau, Timothée Poupart, Cécile Ribout, Yan Ropert-Coudert, Frédéric Angelier
Title Body condition and corticosterone stress response, as markers to investigate effects of human activities on Adélie penguins (Pygoscelis adeliae) Type Journal
Year (down) 2023 Publication Frontiers in Ecology and Evolution Abbreviated Journal
Volume 11 Issue Pages
Keywords Antarctica basal corticosterone disturbance Human activity Pygoscelis adeliae seabird stress response stress-induced corticosterone
Abstract In Antarctica, there is growing concern about the potential effect of anthropogenic activities (i.e., tourism, research) on wildlife, especially since human activities are developing at an unprecedented rate. Although guidelines exist to mitigate negative impacts, fundamental data are currently lacking to reliably assess impacts. Physiological tools, such as circulating corticosterone levels, appear promising to assess the potential impact of human disturbance on Antarctic vertebrates. In this study, we compared the body condition, and the physiological sensitivity to stress (i.e., basal and stress-induced corticosterone level) of adult and chick Adélie penguins between a disturbed and an undisturbed area (i.e., 2 colonies located in the middle of a research station exposed to intense human activities and 2 colonies located on protected islands with minimal human disturbance). We did not find any significant impact of human activities on body condition and corticosterone levels in adults (incubating adults, brooding adults). In chicks, there were significant inter-colony variations in stress-induced corticosterone levels. Specifically, the chicks from the disturbed colonies tended to have higher stress-induced corticosterone levels than the chicks from the protected areas although this difference between areas was not significant. Overall, our study suggests that this species is not dramatically impacted by human activities, at least when humans and penguins have cohabited for several decades. Our results support therefore the idea that this species is likely to be tolerant to human disturbance and this corroborates with the persistence of Adélie penguin colonies in the middle of the research station. However, our results also suggest that chicks might be more sensitive to human disturbance than adults and might therefore potentially suffer from human disturbance. In addition, and independently of human disturbance we also found significant differences in adult body condition, and chick corticosterone level between colonies, suggesting that other individual and environmental variables outweigh the potential minor impact of human disturbance on these variables. Combining corticosterone with complementary stress-related physiological markers, such as heart rate, may strengthen further studies examining whether human disturbance may have subtle detrimental impacts on individuals.
Programme 1091
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Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN 2296-701X Medium
Area Expedition Conference
Notes Approved yes
Call Number Serial 8762
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Author Concepcion Sanchez-Cid, Christoph Keuschnig, Timothy M Vogel, Catherine Larose
Title Impact of in situ solar irradiation on snow bacterial communities and functional potential Type Journal
Year (down) 2023 Publication FEMS Microbiology Ecology Abbreviated Journal
Volume 99 Issue 6 Pages fiad042
Keywords
Abstract Polar regions are increasingly exposed to ultraviolet light due to ozone depletion. Snowpacks contain photochemically active particles that, when irradiated, can lead to the production and accumulation of reactive species that can induce oxidative stress on snow microorganisms. This could generate a selective pressure on snowpack bacteria. In this study, snow microcosms were buried in a snowpack at Ny-Ålesund (Svalbard), either exposed to solar irradiation or incubated in the dark for 10 days, and the bacterial response to solar irradiation was evaluated in situ using a metagenomics approach. Solar irradiation induced a significant decrease in bacterial abundance and richness. Genes involved in glutathione synthesis, sulphur metabolism, and multidrug efflux were significantly enriched in the light, whereas genes related to cell wall assembly and nutrient uptake were more abundant in the dark. This is the first study demonstrating the response of snow bacterial communities to solar irradiation in situ and providing insights into the mechanisms involved. Our research shows that polar sun irradiation is sufficiently intense to impose a selective pressure on snow bacteria and supports the concern that increased ultraviolet exposure due to anthropogenic activities and climatic change could drive critical changes in the structure and functioning of snow bacterial communities.
Programme 1192
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Corporate Author Thesis
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Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0168-6496 ISBN Medium
Area Expedition Conference
Notes Approved yes
Call Number Serial 8539
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