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Institution

University of Rennes

EducationRennes, France
About: University of Rennes is a education organization based out in Rennes, France. It is known for research contribution in the topics: Population & Crystal structure. The organization has 18404 authors who have published 40374 publications receiving 995327 citations.


Papers
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Journal ArticleDOI
03 Dec 1992-Nature
TL;DR: It is reported here that RNase E has an unprecedented substrate specificity for an endoribonuclease, as it preferentially cleaves RNAs that have several unpaired nucleotides at the 5′ end, which may explain how determinants near the5′ end can control rates of mRNA decay in bacteria.
Abstract: DESPITE the variety of messenger RNA half-lives in bacteria (0.5–30 min in Escherichia coli) and their importance in controlling gene expression, their molecular basis remains obscure. The life-time of an entire mRNA molecule can be determined by features near its 5′ end, but no 5′ exoribonuclease has been identified in any prokaryotic organism1–6. A mutation that inactivates E. coli RNase E also increases the average lifetime of bulk E. coli mRNA and of many individual messages, suggesting that cleavage by this endonuclease may be the rate-determining step in the degradation of most mRNAs in E. coli7–16. We have investigated the substrate preference of RNase E in E. coli by using variants of RNA I, a small untranslated RNA whose swift degradation in vivo is initiated by RNase E cleavage at an internal site. We report here that RNase E has an unprecedented substrate specificity for an endoribonuclease, as it preferentially cleaves RNAs that have several unpaired nucleotides at the 5′ end. The sensitivity of RNase E to 5′-terminal base pairing may explain how determinants near the 5′ end can control rates of mRNA decay in bacteria.

213 citations

Proceedings ArticleDOI
24 Feb 2018
TL;DR: This paper formally introduces the qubit allocation problem and provides an exact solution to it, and provides a heuristic solution to qu bit allocation, which is faster than the current solutions already implemented to deal with this problem.
Abstract: In May of 2016, IBM Research has made a quantum processor available in the cloud to the general public. The possibility of programming an actual quantum device has elicited much enthusiasm. Yet, quantum programming still lacks the compiler support that modern programming languages enjoy today. To use universal quantum computers like IBM's, programmers must design low-level circuits. In particular, they must map logical qubits into physical qubits that need to obey connectivity constraints. This task resembles the early days of programming, in which software was built in machine languages. In this paper, we formally introduce the qubit allocation problem and provide an exact solution to it. This optimal algorithm deals with the simple quantum machinery available today; however, it cannot scale up to the more complex architectures scheduled to appear. Thus, we also provide a heuristic solution to qubit allocation, which is faster than the current solutions already implemented to deal with this problem.

213 citations

Journal ArticleDOI
TL;DR: In this article, the future of hedgerows is studied and the role of land use and boundary management plays a major role in determining the floristic composition of hedgers.
Abstract: Hedgerows, rows of trees or shrubs enclosing or separating fields, are man made. They are part of rural landscapes and should not be studied without considering the farming systems and the rural society as a whole. Their species composition depends on the history of the countryside, as well as current farming practices. Land use and boundary management play a major role in determining the floristic composition of hedgerows, and are strongly related to the grain size of the field's mosaic. Hedgerow networks, due to their rectilinear shape, and with their high degree of connection, enhance or interrupt many fluxes in the landscape. Hedgerows act as a corridor of movement and dispersal for many forest species, such as carabids, small mammals, and plants. On the other hand, hedgerows interrupt or slow down air fluxes and the propagules they carry. In the heterogeneous mosaic of fields and wooded patches, hedgerows often increase the functional connectivity of rural landscapes. The future of hedgerows...

213 citations

Journal ArticleDOI
TL;DR: In this article, the authors examine recent theoretical investigations on 2D and 3D hybrid perovskites (HOPs) that combine classical solid-state physics concepts and density functional theory (DFT) simulations as a tool for studying their optoelectronic properties.
Abstract: In this review we examine recent theoretical investigations on 2D and 3D hybrid perovskites (HOPs) that combine classical solid-state physics concepts and density functional theory (DFT) simulations as a tool for studying their optoelectronic properties. Such an approach allows one to define a new class of semiconductors, where the pseudocubic high-temperature perovskite structure plays a central role. Bloch states and k.p. Hamiltonians yield new insight into the influence of lattice distortions, including loss of inversion symmetry, as well as spin–orbit coupling. Electronic band folding and degeneracy, effective masses, and optical absorption are analyzed. Concepts of Bloch and envelope functions, as well as confinement potential, are discussed in the context of layered HOP and 3D HOP heterostructures. Screening and dielectric confinements are important for room-temperature optical properties of 3D and layered HOP, respectively. Nonradiative Auger effects are analyzed for the first time close to the ele...

213 citations

Book ChapterDOI
TL;DR: These in vitro liver models should allow marked advances, especially in cell-based therapies and predictive and mechanistic hepatotoxicity of new drugs and other chemicals, and will benefit from new developments in throughput screening based on cell chips coupled with high-content imaging and in toxicogenomics technologies.
Abstract: In vitro hepatocyte models represent very useful systems in both fundamental research and various application areas. Primary hepatocytes appear as the closest model for the liver in vivo. However, they are phenotypically unstable, have a limited life span and in addition, exhibit large interdonor variability when of human origin. Hepatoma cell lines appear as an alternative but only the HepaRG cell line exhibits various functions, including major cytochrome P450 activities, at levels close to those found in primary hepatocytes. In vitro hepatocyte models have brought a substantial contribution to the understanding of the biochemistry, physiology, and cell biology of the normal and diseased liver and in various application domains such as xenobiotic metabolism and toxicity, virology, parasitology, and more generally cell therapies. In the future, new well-differentiated hepatocyte cell lines derived from tumors or from either embryonic or adult stem cells might be expected and although hepatocytes will continue to be used in various fields, these in vitro liver models should allow marked advances, especially in cell-based therapies and predictive and mechanistic hepatotoxicity of new drugs and other chemicals. All models will benefit from new developments in throughput screening based on cell chips coupled with high-content imaging and in toxicogenomics technologies.

213 citations


Authors

Showing all 18470 results

NameH-indexPapersCitations
Philippe Froguel166820118816
Bart Staels15282486638
Yi Yang143245692268
Geoffrey Burnstock141148899525
Shahrokh F. Shariat118163758900
Lutz Ackermann11666945066
Douglas R. MacFarlane11086454236
Elliott H. Lieb10751257920
Fu-Yuan Wu10736742039
Didier Sornette104129544157
Stefan Hild10345268228
Pierre I. Karakiewicz101120740072
Philippe Dubois101109848086
François Bondu10044069284
Jean-Michel Savéant9851733518
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Performance
Metrics
No. of papers from the Institution in previous years
YearPapers
202321
2022176
20212,655
20202,735
20192,670
20182,378