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Andrew D. Foote, Michael D. Martin, Marie Louis, George Pacheco, Kelly M. Robertson, Mikkel-Holger S. Sinding, Ana R. Amaral, Robin W. Baird, Charles Scott Baker, Lisa Ballance, Jay Barlow, Andrew Brownlow, Tim Collins, Rochelle Constantine, Willy Dabin, Luciano Dalla Rosa, Nicholas J. Davison, John W. Durban, Ruth Esteban, Steven H. Ferguson, Tim Gerrodette, Christophe Guinet, M. Bradley Hanson, Wayne Hoggard, Cory J. D. Matthews, Filipa I. P. Samarra, Renaud de Stephanis, Sara B. Tavares, Paul Tixier, John A. Totterdell, Paul Wade, Laurent Excoffier, M. Thomas P. Gilbert, Jochen B. W. Wolf, Phillip A. Morin. (2019). Killer whale genomes reveal a complex history of recurrent admixture and vicariance (Vol. 28).
Abstract: Reconstruction of the demographic and evolutionary history of populations assuming a consensus tree-like relationship can mask more complex scenarios, which are prevalent in nature. An emerging genomic toolset, which has been most comprehensively harnessed in the reconstruction of human evolutionary history, enables molecular ecologists to elucidate complex population histories. Killer whales have limited extrinsic barriers to dispersal and have radiated globally, and are therefore a good candidate model for the application of such tools. Here, we analyse a global data set of killer whale genomes in a rare attempt to elucidate global population structure in a nonhuman species. We identify a pattern of genetic homogenisation at lower latitudes and the greatest differentiation at high latitudes, even between currently sympatric lineages. The processes underlying the major axis of structure include high drift at the edge of species' range, likely associated with founder effects and allelic surfing during postglacial range expansion. Divergence between Antarctic and non-Antarctic lineages is further driven by ancestry segments with up to four-fold older coalescence time than the genome-wide average; relicts of a previous vicariance during an earlier glacial cycle. Our study further underpins that episodic gene flow is ubiquitous in natural populations, and can occur across great distances and after substantial periods of isolation between populations. Thus, understanding the evolutionary history of a species requires comprehensive geographic sampling and genome-wide data to sample the variation in ancestry within individuals.
Keywords: admixture drift genomics population structure secondary contact
Programme: 109
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Andrew W. Mann, Mackenna L. Wood, Stephen P. Schmidt, Madyson G. Barber, James E. Owen, Benjamin M. Tofflemire, Elisabeth R. Newton, Eric E. Mamajek, Jonathan L. Bush, Gregory N. Mace, Adam L. Kraus, Pa Chia Thao, Andrew Vanderburg, Joe Llama, Christopher M. Johns-Krull, L. Prato, Asa G. Stahl, Shih-Yun Tang, Matthew J. Fields, Karen A. Collins, Kevin I. Collins, Tianjun Gan, Eric L. N. Jensen, Jacob Kamler, Richard P. Schwarz, Elise Furlan, Crystal L. Gnilka, Steve B. Howell, Kathryn V. Lester, Dylan A. Owens, Olga Suarez, Djamel Mekarnia, Tristan Guillot, Lyu Abe, Amaury H. M. J. Triaud, Marshall C. Johnson, Reilly P. Milburn, Aaron C. Rizzuto, Samuel N. Quinn, Ronan Kerr, George R. Ricker, Roland Vanderspek, David W. Latham, Sara Seager, Joshua N. Winn, Jon M. Jenkins, Natalia M. Guerrero, Avi Shporer, Joshua E. Schlieder, Brian McLean, Bill Wohler. (2022). TESS Hunt for Young and Maturing Exoplanets (THYME). VI. An 11 Myr Giant Planet Transiting a Very-low-mass Star in Lower Centaurus Crux (Vol. 163).
Abstract: Mature super-Earths and sub-Neptunes are predicted to be ≃ Jovian radius when younger than 10 Myr. Thus, we expect to find 5–15 R ⊕ planets around young stars even if their older counterparts harbor none. We report the discovery and validation of TOI 1227b, a 0.85 ± 0.05 R J (9.5 R ⊕) planet transiting a very-low-mass star (0.170 ± 0.015 M ⊙) every 27.4 days. TOI 1227's kinematics and strong lithium absorption confirm that it is a member of a previously discovered subgroup in the Lower Centaurus Crux OB association, which we designate the Musca group. We derive an age of 11 ± 2 Myr for Musca, based on lithium, rotation, and the color–magnitude diagram of Musca members. The TESS data and ground-based follow-up show a deep (2.5%) transit. We use multiwavelength transit observations and radial velocities from the IGRINS spectrograph to validate the signal as planetary in nature, and we obtain an upper limit on the planet mass of ≃0.5 M J. Because such large planets are exceptionally rare around mature low-mass stars, we suggest that TOI 1227b is still contracting and will eventually turn into one of the more common <5 R ⊕ planets.
Programme: 1066
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Andrews JT, Belt ST, Olafsdottir S, Masse G, Vare LL, . (2009). Sea ice and marine climate variability for NW Iceland/Denmark Strait over the last 2000 cal. yr BP
. The Holocene, 19(5), 775–784.
Abstract: MD99-2263 is a 46 cm box core collected from Djupall, a trough that cuts across the NW Iceland Shelf and ends above Denmark Strait. We provide a multiproxy record that documents changes in the regional marine climate over the last ~1700 yr. The depth/age model is based on seven calibrated radiocarbon dates on mollusk shells and on 210Pb and 137Cs. Sediment accumulation rates were variable (0.2--0.8 mm/yr) but increased dramatically ~AD 1500. Grain-size, magnetic properties, quantitative mineral composition of the <2 mm sediment fraction, benthic foraminiferal composition, benthic and planktic {Delta}18O ratios, and abundances/fluxes of the sea ice biomarker IP25 were determined. To better compare the various proxies, 12 of the critical climate proxies were co-ordinated into 100-yr/sample time series, which were examined by Principal Component Analysis. The 1st axis explained 49% of the variance and the 2nd axis explained an additional 17%. The variables most strongly associated with the 1st axis were sediment properties (phi mean, clay%) and the sea ice biomarker. Mineralogical indicators of drift ice rafting, such as the presence of quartz and potassium- and sodium-feldspars, coincide with the IP25 biomarker data and show an increase after AD 1200, but high values of quartz and some feldspars also occurred between c. AD 300 and 900 with pronounced minima between AD 900 and 1100. Overall, our data suggest a simple two-fold division in climate conditions over the last 1700 yr, with the major change occurring c. AD 1200. In the last few decades, conditions have reverted towards those experienced prior to AD 1200.
Programme: 452
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Andrews-Goff V, Hindell MA, Field IC, Wheatley KE, Charrassin J, . (2010). Factors influencing the winter haulout behaviour of Weddell seals: consequences for satellite telemetry
. Endang Species Res, 10, 83–92.
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Andriambahoaka Z. (2008). Modélisation régionale du champ magnétique et établissement de cartes magnétiques détaillées appliqués à Madagascar.
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Andriambahoaka, Z., Schott, J.J., and Ranaivonomenjanahary F. (2007). Repeat station data reduction using the CM4 model. (Vol. 398). Bachelor's thesis, , .
Abstract: Publs. Inst. Geophys. Pol. Acad. Sc.
Programme: 139;905
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Angela K. Gore, And Yan Axel Gómez Coutouly. (2019). New Investigations at Little Panguingue Creek, Nenana Valley, Interior Alaska.
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Angelica Psaridi, François Bouchy, Monika Lendl, Babatunde Akinsanmi, Keivan G. Stassun, Barry Smalley, David J. Armstrong, Saburo Howard, Solène Ulmer-Moll, Nolan Grieves, Khalid Barkaoui, Joseph E. Rodriguez, Edward M. Bryant, Olga Suárez, Tristan Guillot, Phil Evans, Omar Attia, Robert A. Wittenmyer, Samuel W. Yee, Karen A. Collins, George Zhou, Franck Galland, Léna Parc, Stéphane Udry, Pedro Figueira, Carl Ziegler, Christoph Mordasini, Joshua N. Winn, Sara Seager, Jon M. Jenkins, Joseph D. Twicken, Rafael Brahm, Matías I. Jones, Lyu Abe, Brett Addison, César Briceño, Joshua T. Briegal, Kevin I. Collins, Tansu Daylan, Phillip Eigmüller, Gabor Furesz, Natalia M. Guerrero, Janis Hagelberg, Alexis Heitzmann, Rebekah Hounsell, Chelsea X. Huang, Andreas Krenn, Nicholas M. Law, Andrew W. Mann, James McCormac, Djamel Mékarnia, Dany Mounzer, Louise D. Nielsen, Ares Osborn, Yared Reinarz, Ramotholo R. Sefako, Michal Steiner, Paul A. Strøm, Amaury H. M. J. Triaud, Roland Vanderspek, Leonardo Vanzi, Jose I. Vines, Christopher A. Watson, Duncan J. Wright, Abner Zapata. (2023). Three Saturn-mass planets transiting F-type stars revealed with TESS and HARPS – TOI-615b, TOI-622b, and TOI-2641b (Vol. 675).
Abstract: While the sample of confirmed exoplanets continues to grow, the population of transiting exoplanets around early-type stars is still limited. These planets allow us to investigate the planet properties and formation pathways over a wide range of stellar masses and study the impact of high irradiation on hot Jupiters orbiting such stars. We report the discovery of TOI-615b, TOI-622b, and TOI-2641b, three Saturn-mass planets transiting main sequence, F-type stars. The planets were identified by the Transiting Exoplanet Survey Satellite (TESS) and confirmed with complementary ground-based and radial velocity observations. TOI-615b is a highly irradiated (~1277 F⊕) and bloated Saturn-mass planet (1.69−0.06+0.05 RJup and 0.43−0.08+0.09 MJup) in a 4.66 day orbit transiting a 6850 K star. TOI-622b has a radius of 0.82−0.03+0.03 RJup and a mass of 0.30−0.08+0.07 MJup in a 6.40 day orbit. Despite its high insolation flux (~600 F⊕), TOI-622b does not show any evidence of radius inflation. TOI-2641b is a 0.39−0.04+0.02 MJup planet in a 4.88 day orbit with a grazing transit (b = 1.04−0.06+0.05) that results in a poorly constrained radius of 1.61−0.64+0.46 RJup. Additionally, TOI-615b is considered attractive for atmospheric studies via transmission spectroscopy with ground-based spectrographs and JWST. Future atmospheric and spin-orbit alignment observations are essential since they can provide information on the atmospheric composition, formation, and migration of exoplanets across various stellar types.
Programme: 1066
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ANGELIER F, CHASTEL O. (2009). Stress, prolactin and parental investment in birds: A review. Gen. Comp. Endocrinol., 163, 142–148.
Abstract: In this paper, we review the relationships that link avian parental behavior, stress (acute or chronic) and energetic constraints to the secretion of prolactin, the ‘parental hormone’. Prolactin secretion is stimulated by exposure of the parent to tactile and visual stimuli from the nest, the eggs or the chicks, while prolactin facilitates/stimulates the expression of parental behaviors, such as incubating, brooding or feeding. Because of this role of prolactin in the expression of parental behaviors, we suggest that absolute circulating prolactin levels may reflect to the extent to which individuals provide parental care (i.e., parental effort). Stressors and energetic constraints (acute or chronic) depress prolactin levels (‘the prolactin stress response’) and this may be adaptive because it may disrupt the current parental effort of an individual and promote its survival. Alternatively, an attenuation of the prolactin stress response can be considered as a hormonal tactic permitting the maintenance of parental care to the detriment of parental survival during stressful situations. Therefore, we suggest that the magnitude of the prolactin stress response may reflect parental investment. Finally, we detail the interaction that links corticosterone, prolactin and stress in bird parents. We suggest that corticosterone and prolactin may mediate different components of the stress response, and, therefore, we emphasize the importance of considering both hormones when investigating the hormonal basis of parental investment.
Programme: 330
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ANGELIER F, CLEMENT-CHASTEL C, GABRIELSEN GW, CHASTEL O. (2007). Corticosterone and Time-activity budget: an experiment with Black-legged kittiwakes. Hormones and behavior, 52, 487–491.
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