Institution
University of Rennes
Education•Rennes, France•
About: University of Rennes is a education organization based out in Rennes, France. It is known for research contribution in the topics: Population & Catalysis. The organization has 18404 authors who have published 40374 publications receiving 995327 citations.
Papers published on a yearly basis
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Université catholique de Louvain1, Katholieke Universiteit Leuven2, University of Antwerp3, Royal Belgian Institute of Natural Sciences4, Ghent University5, University of Rennes6, Université de Namur7, National Research Council8, Helmholtz Centre for Environmental Research - UFZ9, Universidade Estadual de Maringá10, University of Turin11, University of Hasselt12
TL;DR: It is demonstrated that urban communities generally consist of smaller species, and that the general trend towards smaller-sized species is overruled by filtering for larger species when there is positive covariation between size and dispersal, which can mitigate the low connectivity of ecological resources in urban settings.
Abstract: Body size is intrinsically linked to metabolic rate and life-history traits, and is a crucial determinant of food webs and community dynamics1,2. The increased temperatures associated with the urban-heat-island effect result in increased metabolic costs and are expected to drive shifts to smaller body sizes
3
. Urban environments are, however, also characterized by substantial habitat fragmentation
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, which favours mobile species. Here, using a replicated, spatially nested sampling design across ten animal taxonomic groups, we show that urban communities generally consist of smaller species. In addition, although we show urban warming for three habitat types and associated reduced community-weighted mean body sizes for four taxa, three taxa display a shift to larger species along the urbanization gradients. Our results show that the general trend towards smaller-sized species is overruled by filtering for larger species when there is positive covariation between size and dispersal, a process that can mitigate the low connectivity of ecological resources in urban settings
5
. We thus demonstrate that the urban-heat-island effect and urban habitat fragmentation are associated with contrasting community-level shifts in body size that critically depend on the association between body size and dispersal. Because body size determines the structure and dynamics of ecological networks
1
, such shifts may affect urban ecosystem function. The urban-heat-island effect drives community-level shifts towards smaller body sizes; however, habitat fragmentation caused by urbanization favours larger body sizes in species with positive size–dispersal links.
175 citations
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TL;DR: In this paper, des conditions suffisantes pour que la martingale locale ℰ (M) definie par C. Doleans-Dade soit une Martingale uniformement integrable.
Abstract: Nous donnons des conditions suffisantes pour que la martingale localeℰ (M) definie par C. Doleans-Dade soit une martingale uniformement integrable. Le lien est etabli avec la martingale locale exponentielle α(N, z, Μ) de Kunita-Watanabe, ce qui permet de generaliser un theoreme de Novikov.
175 citations
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TL;DR: An overview of the different types of virus-aphid relationships, state-of-the-art knowledge of the molecular processes underlying these interactions, and the remaining black boxes waiting to be opened in the near future is presented.
175 citations
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TL;DR: This new dynamical picture of intermittency provides a direct link between the microscale flow, its intermittent properties, and non-Fickian dispersion.
Abstract: We study the intermittency of fluid velocities in porous media and its relation to anomalous dispersion. Lagrangian velocities measured at equidistant points along streamlines are shown to form a spatial Markov process. As a consequence of this remarkable property, the dispersion of fluid particles can be described by a continuous time random walk with correlated temporal increments. This new dynamical picture of intermittency provides a direct link between the microscale flow, its intermittent properties, and non-Fickian dispersion.
175 citations
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TL;DR: Magneto-optical spectroscopy shows that the dark exciton state in single formamidinium lead bromide perovskite nanocrystals is located below the bright exciton triplet, which explains the intense brightness of the nanoparticles.
Abstract: Lead halide perovskites have emerged as promising new semiconductor materials for high-efficiency photovoltaics, light-emitting applications and quantum optical technologies. Their luminescence properties are governed by the formation and radiative recombination of bound electron-hole pairs known as excitons, whose bright or dark character of the ground state remains unknown and debated. While symmetry analysis predicts a singlet non-emissive ground exciton topped with a bright exciton triplet, it has been predicted that the Rashba effect may reverse the bright and dark level ordering. Here, we provide the direct spectroscopic signature of the dark exciton emission in the low-temperature photoluminescence of single formamidinium lead bromide perovskite nanocrystals under magnetic fields. The dark singlet is located several millielectronvolts below the bright triplet, in fair agreement with an estimation of the long-range electron-hole exchange interaction. Nevertheless, these perovskites display an intense luminescence because of an extremely reduced bright-to-dark phonon-assisted relaxation.
175 citations
Authors
Showing all 18470 results
Name | H-index | Papers | Citations |
---|---|---|---|
Philippe Froguel | 166 | 820 | 118816 |
Bart Staels | 152 | 824 | 86638 |
Yi Yang | 143 | 2456 | 92268 |
Geoffrey Burnstock | 141 | 1488 | 99525 |
Shahrokh F. Shariat | 118 | 1637 | 58900 |
Lutz Ackermann | 116 | 669 | 45066 |
Douglas R. MacFarlane | 110 | 864 | 54236 |
Elliott H. Lieb | 107 | 512 | 57920 |
Fu-Yuan Wu | 107 | 367 | 42039 |
Didier Sornette | 104 | 1295 | 44157 |
Stefan Hild | 103 | 452 | 68228 |
Pierre I. Karakiewicz | 101 | 1207 | 40072 |
Philippe Dubois | 101 | 1098 | 48086 |
François Bondu | 100 | 440 | 69284 |
Jean-Michel Savéant | 98 | 517 | 33518 |