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. (2012). Antarctic, Sub-Antarctic and cold temperate echinoid database
. ZOOKEYS, 204, 47–52.
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Merieme Chadid, Chris Sneden and George Preston. (2016). Spectroscopic Comparison of Metal–Rich RRab Stars of theGalactic Field with Their Metal–Poor Counterparts. Astrophys. J., 835(2), 187.
Abstract: We investigate atmospheric properties of 35 stable RRab stars that possess the full ranges of period, light amplitude, and metal abundance found in Galactic RR Lyrae stars. Our results are derived from several thousand echelle spectra obtained over several years with the du Pont telescope of Las Campanas Observatory. Radial velocities of metal lines and the Hα line were used to construct curves of radial velocity versus pulsation phase. From these we estimated radial velocity amplitudes for metal lines (formed near the photosphere) and Hα Doppler cores (formed at small optical depths). We also measured Hα emission fluxes when they appear during primary light rises. Spectra shifted to rest wavelengths, binned into small phase intervals, and co-added were used to perform model atmospheric and abundance analyses. The derived metallicities and those of some previous spectroscopic surveys were combined to produce a new calibration of the Layden abundance scale. We then divided our RRab sample into metal-rich (disk) and metal-poor (halo) groups at [Fe/H] = −1.0; the atmospheres of RRab families, so defined, differ with respect to (a) peak strength of Hα emission flux, (b) Hα radial velocity amplitude, (c) dynamical gravity, (d) stellar radius variation, (e) secondary acceleration during the photometric bump that precedes minimum light, and (f) duration of Hα line-doubling. We also detected Hα line-doubling during the
Programme: 1096
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. (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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. (2015). Heavy metal contamination and hepatic toxicological responses in brown trout (Salmo trutta) from the Kerguelen Islands. (Vol. 34). Bachelor's thesis, , .
Keywords: biomarkers Brown trout fish freshwater liver sub-Antarctic
Programme: 409
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. (2012). Correlative and dynamic species distribution modelling for ecological predictions in the Antarctic: a cross-disciplinary concept
. POLAR RESEARCH, 31(110091).
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. (2012). Correlative and dynamic species distribution modelling for ecological predictions in the Antarctic: a cross-disciplinary concept
. POLAR RESEARCH, 31, 110091.
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Alexander Kokhanovsky, Maxim Lamare, Olaf Danne, Carsten Brockmann, Marie Dumont, Ghislain Picard, Laurent Arnaud, Vincent Favier, Bruno Jourdain, Emmanuel Le Meur, Biagio Di Mauro, Teruo Aoki, Masashi Niwano, Vladimir Rozanov, Sergey Korkin, Sepp Kipfstuhl, Johannes Freitag, Maria Hoerhold, Alexandra Zuhr, Diana Vladimirova, Anne-Katrine Faber, Hans Christian Steen-Larsen, Sonja Wahl, Jonas K. Andersen, Baptiste Vandecrux, Dirk van As, Kenneth D. Mankoff, Michael Kern, Eleonora Zege, Jason E. Box. (2019). Retrieval of snow properties from the Sentinel-3 Ocean and Land Colour Instrument (Vol. 11). Bachelor's thesis, , .
Keywords: albedo OLCI optical remote sensing Sentinel 3 snow characteristics sow grain size specific surface area
Programme: 1110
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. (2019). Variations of Secondary Metabolites among Natural Populations of Sub-Antarctic Ranunculus Species Suggest Functional Redundancy and Versatility (Vol. 8). Bachelor's thesis, , .
Keywords: Ranunculus biternatus Ranunculus moseleyi Ranunculus pseudotrullifolius amines environment natural populations quercetins redundancy secondary metabolite variation sub-Antarctic plants
Programme: 136,1116
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David Renault. (2020). A Review of the Phenotypic Traits Associated with Insect Dispersal Polymorphism, and Experimental Designs for Sorting out Resident and Disperser Phenotypes (Vol. 11). Bachelor's thesis, , .
Abstract: Dispersal represents a key life-history trait with several implications for the fitness of organisms, population dynamics and resilience, local adaptation, meta-population dynamics, range shifting, and biological invasions. Plastic and evolutionary changes of dispersal traits have been intensively studied over the past decades in entomology, in particular in wing-dimorphic insects for which literature reviews are available. Importantly, dispersal polymorphism also exists in wing-monomorphic and wingless insects, and except for butterflies, fewer syntheses are available. In this perspective, by integrating the very latest research in the fast moving field of insect dispersal ecology, this review article provides an overview of our current knowledge of dispersal polymorphism in insects. In a first part, some of the most often used experimental methodologies for the separation of dispersers and residents in wing-monomorphic and wingless insects are presented. Then, the existing knowledge on the morphological and life-history trait differences between resident and disperser phenotypes is synthetized. In a last part, the effects of range expansion on dispersal traits and performance is examined, in particular for insects from range edges and invasion fronts. Finally, some research perspectives are proposed in the last part of the review.
Keywords: fecundity hostile matrix life-history mating morphology movement range expansion reproduction wing-dimorphic wing-monomorphic
Programme: 136
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. (2013). The Dynamic Arctic Snow Pack: An Unexplored Environment for Microbial Diversity and Activity
. biology, 2(1), 317–330.
Abstract: The Arctic environment is undergoing changes due to climate shifts, receiving contaminants from distant sources and experiencing increased human activity. Climate change may alter microbial functioning by increasing growth rates and substrate use due to increased temperature. This may lead to changes of process rates and shifts in the structure of microbial communities. Biodiversity may increase as the Arctic warms and population shifts occur as psychrophilic/psychrotolerant species disappear in favor of more mesophylic ones. In order to predict how ecological processes will evolve as a function of global change, it is essential to identify which populations participate in each process, how they vary physiologically, and how the relative abundance, activity and community structure will change under altered environmental conditions. This review covers aspects of the importance and implication of snowpack in microbial ecology emphasizing the diversity and activity of these critical members of cold zone ecosystems.
Keywords: biogeochemical cycling, microbial ecology, snow, Arctic,
Programme: 399
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