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Albane Barbero, Camille Blouzon, Joël Savarino, Nicolas Caillon, Aurélien Dommergue, Roberto Grilli. (2020). A compact incoherent broadband cavity-enhanced absorption spectrometer for trace detection of nitrogen oxides, iodine oxide and glyoxal at levels below parts per billion for field applications (Vol. 13). Bachelor's thesis, , .
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Maxime Pineaux, Thomas Merkling, Etienne Danchin, Scott Hatch, David Duneau, Pierrick Blanchard, Sarah Leclaire. (2020). Sex and hatching order modulate the association between MHC-II diversity and fitness in early-life stages of a wild seabird (Vol. 29).
Abstract: Genes of the major histocompatibility complex (MHC) play a pivotal role in parasite resistance, and their allelic diversity has been associated with fitness variations in several taxa. However, studies report inconsistencies in the direction of this association, with either positive, quadratic or no association being described. These discrepancies may arise because the fitness costs and benefits of MHC diversity differ among individuals depending on their exposure and immune responses to parasites. Here, we investigated in black-legged kittiwake (Rissa tridactyla) chicks whether associations between MHC class-II diversity and fitness vary with sex and hatching order. MHC-II diversity was positively associated with growth and tick clearance in female chicks, but not in male chicks. Our data also revealed a positive association between MHC-II diversity and survival in second-hatched female chicks (two eggs being the typical clutch size). These findings may result from condition-dependent parasite infections differentially impacting sexes in relation to hatching order. We thus suggest that it may be important to account for individual heterogeneities in traits that potentially exert selective pressures on MHC diversity in order to properly predict MHC–fitness associations.
Keywords: divergent allele advantage fitness heterozygote advantage immunity Ixodes uriae parasite-mediated selection
Programme: 1162
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Rémi Bigonneau, Romain Bazire, Cédric Marteau, Christophe Barbraud, Joan Ferrer-Obiol, Karine Delord. (2020). First record of Black-winged Pratincole Glareola nordmanni for Amsterdam Island, Indian Ocean (Vol. 27). Bachelor's thesis, , .
Abstract: Première mention de la Glaréole à ailes noires Glareola nordmanni pour l’Île Amsterdam, Océan Indien. Une Glaréole à ailes noires Glareola nordmanni de premier hiver à été observée sur l’Île Amsterdam, dans le sud de l’Océan indien, les 12–16 novembre 2013. Il s’agît de la première donnée de cette espèce paléarctique pour l’île. Les mentions antérieures les plus proches proviennent de l’île d’Alphonse, aux Seychelles, à environ 4.200 km de l’Île Amsterdam.
Programme: 109
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Vincent Lesur, Aude Chambodut. (2020). The French network of magnetic observatories.
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I. Wardinski, D. Saturnino, H. Amit, A. Chambodut, B. Langlais, M. Mandea, E. Thébault. (2020). Geomagnetic core field models and secular variation forecasts for the 13th International Geomagnetic Reference Field (IGRF-13) (Vol. 72).
Abstract: Observations of the geomagnetic field taken at Earth’s surface and at satellite altitude are combined to construct continuous models of the geomagnetic field and its secular variation from 1957 to 2020. From these parent models, we derive candidate main field models for the epochs 2015 and 2020 to the 13th generation of the International Geomagnetic Reference Field (IGRF). The secular variation candidate model for the period 2020–2025 is derived from a forecast of the secular variation in 2022.5, which results from a multi-variate singular spectrum analysis of the secular variation from 1957 to 2020.
Keywords: Forecasts of the geomagnetic field Geomagnetic field models Geomagnetic secular variation The geomagnetic field
Programme: 139
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L. G. Bouma, J. D. Hartman, R. Brahm, P. Evans, K. A. Collins, G. Zhou, P. Sarkis, S. N. Quinn, J. de Leon, J. Livingston, C. Bergmann, K. G. Stassun, W. Bhatti, J. N. Winn, G. Á Bakos, L. Abe, N. Crouzet, G. Dransfield, T. Guillot, W. Marie-Sainte, D. Mékarnia, A. H. M. J. Triaud, C. G. Tinney, T. Henning, N. Espinoza, A. Jordán, M. Barbieri, S. Nandakumar, T. Trifonov, J. I. Vines, M. Vuckovic, C. Ziegler, N. Law, A. W. Mann, G. R. Ricker, R. Vanderspek, S. Seager, J. M. Jenkins, C. J. Burke, D. Dragomir, A. M. Levine, E. V. Quintana, J. E. Rodriguez, J. C. Smith, B. Wohler. (2020). Cluster Difference Imaging Photometric Survey. II. TOI 837: A Young Validated Planet in IC 2602 (Vol. 160). Bachelor's thesis, , .
Abstract: We report the discovery of TOI 837b and its validation as a transiting planet. We characterize the system using data from the NASA TESS mission, the ESA Gaia mission, ground-based photometry from El Sauce and ASTEP400, and spectroscopy from CHIRON, FEROS, and Veloce. We find that TOI 837 is a $T=9.9$ mag G0/F9 dwarf in the southern open cluster IC 2602. The star and planet are therefore $35^{+11}{-5}$ million years old. Combining the transit photometry with a prior on the stellar parameters derived from the cluster color-magnitude diagram, we find that the planet has an orbital period of $8.3\,{\rm d}$ and is slightly smaller than Jupiter ($R{\rm p} = 0.77^{+0.09}{-0.07} \,R{\rm Jup}$). From radial velocity monitoring, we limit $M{\rm p}\sin i$ to less than 1.20 $M{\rm Jup}$ (3-$\sigma$). The transits either graze or nearly graze the stellar limb. Grazing transits are a cause for concern, as they are often indicative of astrophysical false positive scenarios. Our follow-up data show that such scenarios are unlikely. Our combined multi-color photometry, high-resolution imaging, and radial velocities rule out hierarchical eclipsing binary scenarios. Background eclipsing binary scenarios, though limited by speckle imaging, remain a 0.2% possibility. TOI 837b is therefore a validated adolescent exoplanet. The planetary nature of the system can be confirmed or refuted through observations of the stellar obliquity and the planetary mass. Such observations may also improve our understanding of how the physical and orbital properties of exoplanets change in time.
Keywords: Astrophysics – Earth and Planetary Astrophysics Astrophysics – Solar and Stellar Astrophysics
Programme: 1066
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Razzolini Julia. (2020). Croissance musculaire chez le poussin de manchot royal, liens avec la saisonnalité et la condition corporelle. Bachelor's thesis, , .
Abstract: One of the fundamental principles of life history trait theory is the existence of trade-offs. The amount of energy available to living beings is a limited resource that must be shared among different biological functions. The combination of traits best suited to ecological constraints will be selected.
Growth is a crucial phase during which the future phenotype of the adult is established. This period between birth and the acquisition of independence from parents is characterized by very fast stature and weight growth and tissue maturation, particularly in bone and muscle. This phenomenon is marked by sustained parental nutrition. On an intraspecific scale, variations in individual chick growth may reflect the quality/experience of the parents. In some species, parental dietary intake may, regardless of quality, show wide seasonal fluctuations due to environmental changes and for developing individuals the quantity and quality of nutrients ingested and metabolized may be a limiting factor in growth. There is little information to understand the trade-offs in energy allocation that will be established to ensure survival and growth of the young in the case of inadequate dietary intakes.
The king penguin chick is an atypical animal model for the study of these strategies. This seabird has an unusually long one-year development cycle for a bird and its growth is interrupted by a period of severe food restriction during the 4 months of the southern winter. In addition, exceptionally with a penguin, the period of initiation of reproduction is asynchronous and extends over several months. A direct consequence is a shorter time of accumulation of energy reserves in late-born chicks. We aim to determine whether the particularly long cycle of this chick and the environmental constraints to which it is subjected result in particular adaptations in terms of the relative development of the two muscle belts, pelvic and pectoral, and whether this growth compromise is expressed in the same way in early and late born chicks.
Programme: 119
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Nicolas Crouzet, Abdelkrim Agabi, Tristan Guillot, Lyu Abe, François-Xavier Schmider, Djamel Mékarnia, Amaury H. M. J. Triaud, Yves Bresson, Nicolas Mauclert, Christophe Bailet, Dennis Breeveld, Sander Blommaert, Brian Shortt, Jean-Baptiste Daban, Anne-Marie Lagrange, Romain Touzé, Justin Dufour, Valentin Stee, Jocelyn Caruana. (2020). Towards ASTEP+, a two-color photometric telescope at Dome C, Antarctica (Vol. 11447).
Abstract: Dome C, Antarctica is unique in particular for long-duration astronomical observations due to the excellent weather conditions and nearly uninterrupted nights during the Southern winter period. The 40 cm telescope ASTEP has been operating successfully at the Concordia base, at Dome C, since 2010. We describe the new ASTEP+, a major upgrade of its camera box which will allow it to observe simultaneously in two colors. Approximately three times more photons will be collected for science, yielding more sensitive and accurate observations. The southern location of the telescope means that it is ideally located to follow-up exoplanetary targets in preparation for the future JWST and Ariel observations, in particular when located in the southern continuous viewing zones of these space-based telescopes.
Programme: 1066
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Christophe Barbraud, Adrien Chaigne, Maxime Loubon, Olivier Lamy, Fabrice Le Bouard. (2020). An estimate of the South Georgia diving petrel Pelecanoides georgicus population at Ile de la Possession, Crozet archipelago (Vol. 32).
Abstract: Burrow-nesting seabirds constitute an important part of seabird diversity, yet accurate estimates of their abundance are largely lacking, limiting our understanding of their population dynamics and conservation status. We conducted a survey to estimate the number of South Georgia diving petrel (Pelecanoides georgicus) burrows during the 2013–14 breeding season on Ile de la Possession, Crozet archipelago, southern Indian Ocean. We used distance sampling and acoustic playback in order to estimate burrow densities in a priori-selected favourable nesting areas. A total of 855 burrows were detected. The mean altitude of burrows was 601.8 ± 69.4 m. The mean burrow detection distance was 1.77 ± 1.63 m. The burrow density was estimated at 15.649 burrows ha-1 (95% confidence interval (CI): 10.245–23.903) and the slope-corrected total favourable area was 2365.53 ha, which yielded an estimate 37 018 burrows (95% CI: 24 235–56 544). The playback response rate was 15.8 ± 1.3%, and 40.8 ± 1.7% of burrows were occupied or showed signs of occupation. Occupancy rates were low compared to those measured by systematic burrow inspection in other studies. Assuming that laying occurred in 80–93% of the estimated number of burrows, as estimated by previous studies, gives an estimate of 29 614 (95% CI: 19 388–45 235) to 34 426 (95% CI: 22 538–52 585) breeding pairs.
Keywords: acoustic playback burrowing petrel detection probability distance sampling Procellariiformes
Programme: 109
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Fabienne Joliet, Véronique Van Tilbeurgh, Anne Atlan. (2020). La valeur d’existence du monde vivant selon les Inuits du Nunavik et les Occidentaux aux Kerguelen (Vol. 732).
Abstract: Dans le contexte actuel de transition socio-écologique internationale, l’objectif de cet article est d’interroger la relation entre les humains et les autres vivants et choses naturelles dans les derniers espaces de vaste naturalité aux pôles. C’est à travers la notion de valeur d’existence que cette relation sera analysée dans ses retranchements chez les Inuits qui habitent le Nunavik en subarctique et les Occidentaux qui veillent sur les Kerguelen en subantarctique. Plus particulièrement, c’est la nature du lien qu’ils entretiennent avec les vivants non-humains et autres choses naturelles, et ses registres de valeurs qui sont étudiées.Ces enquêtes boréales et australes en zone protégée ou bien à ses abords montrent ainsi que ce qui prédomine, c’est le fait qu’il est attribué aux éléments naturels une valeur d’existence en fonction d’un esprit commun spirituel ou bien d’une enveloppe commune charnelle d’« être vivant ». Selon ces principes, les modalités prises par l’attribution de la valeur d’existence changent : les humains se concevant soit, comme une partie d’un ensemble au même titre que les autres vivants et choses naturelles ayant un esprit ou conscience, soit comme maîtres et protecteurs des autres vivants et choses naturelles, en tant qu’ayant une fonction dominante au sein d’« êtres vivants ». Dans cette perspective, le territoire joue un rôle spécifique favorisant l’existence même de cette valeur au-delà de ses fonctions de régulation couramment retenues.
Programme: 136
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