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Université de Fribourg

Enigmatic dinosaur precursors bridge the gap to the origin of Pterosauria

Ezcurra, Martín D. ; Nesbitt, Sterling J. ; Bronzati, Mario ; Vecchia, Fabio Marco Dalla ; Agnolin, Federico L. ; Benson, Roger B. J. ; Egli, Federico Brissón ; Cabreira, Sergio F. ; Evers, Serjoscha W. ; Gentil, Adriel R. ; Irmis, Randall B. ; Martinelli, Agustín G. ; Novas, Fernando E. ; Silva, Lúcio Roberto da ; Smith, Nathan D. ; Stocker, Michelle R. ; Turner, Alan H. ; Langer, Max C.

In: Nature, 2020, vol. 588, no. 2020-7838, p. 445–449

Pterosaurs were the first vertebrates to evolve powered flight1 and comprised one of the main evolutionary radiations in terrestrial ecosystems of the Mesozoic era (approximately 252–66 million years ago), but their origin has remained an unresolved enigma in palaeontology since the nineteenth century2,3,4. These flying reptiles have been hypothesized to be the close relatives of a wide...

Université de Fribourg

Parallel heuristic community detection method based on node similarity

Zhou, Qiang ; Cai, Shi-Min ; Zhang, Yi-Cheng

In: IEEE Access, 2019, vol. 7, p. 184145–184159

Community structure discovery can help us better understand the capabilities and functions of the network. However, many existing methods have failed to identify nodes in communities accurately. In this paper, we proposed a heuristic community detection method based on node similarities that are computed by assigning different edge weight influence factors based on different neighbor types of...

Université de Fribourg

Hypersatellite x-ray decay of $3d$ hollow-$K$-shell atoms produced by heavy-ion impact

Maillard, Yves-Patrick ; Dousse, Jean-Claude ; Hoszowska, Joanna ; Berset, Michel ; Mauron, Olivier ; Raboud, Pierre-Alexandre ; Kavčič, Matjaz ; Rzadkiewicz, J. ; Banaś, Dariusz ; Tökési, K.

In: Physical Review A, 2018, vol. 98, no. 1, p. 012705

We report on the radiative decay of double K-shell vacancy states produced in solid Ca, V, Fe, and Cu targets by impact with about 10 MeV/amu C and Ne ions. The resulting K hypersatellite x-ray emission spectra were measured by means of high- energy-resolution spectroscopy using a von Hamos bent crystal spectrometer. The experiment was carried out at the Philips variable energy cyclotron of...

Université de Fribourg

Electronic fine structure calculation of metal complexes with three-open-shell s, d, and p configurations

Ramanantoanina, Harry ; Daul, Claude

In: Journal of Molecular Modeling, 2017, vol. 23, no. 8, p. 243

The ligand field density functional theory (LFDFT) algorithm is extended to treat the electronic structure and properties of systems with three-open-shell electron configurations, exemplified in this work by the calculation of the core and semi-core 1s, 2s, and 3s one-electron excitations in compounds containing transition metal ions. The work presents a model to non-empirically resolve the...

Université de Fribourg

The comparative osteology of Plesiochelys bigleri n. sp., a new coastal marine turtle from the Late Jurassic of Porrentruy (Switzerland)

Püntener​, Christian ; Anquetin, Jérémy ; Billon-Bruyat, Jean-Paul

In: PeerJ, 2017, vol. 5, p. e3482

During the Late Jurassic, several groups of eucryptodiran turtles inhabited the shallow epicontinental seas of Western Europe. Plesiochelyidae are an important part of this first radiation of crown-group turtles into coastal marine ecosystems. Fossils of Plesiochelyidae occur in many European localities, and are especially abundant in the Kimmeridgian layers of the Swiss Jura Mountains (Solothurn...

Université de Fribourg

Evolution properties of online user preference diversity

Guo, Qiang ; Ji, Lei ; Liu, Jian-Guo ; Han, Jingti

In: Physica A: Statistical Mechanics and its Applications, 2017, vol. 468, p. 698–713

Detecting the evolution properties of online user preference diversity is of significance for deeply understanding online collective behaviors. In this paper, we empirically explore the evolution patterns of online user rating preference, where the preference diversity is measured by the variation coefficient of the user rating sequence. The statistical results for four real systems show...