oalib

Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99

Submit

Any time

2019 ( 48 )

2018 ( 248 )

2017 ( 272 )

2016 ( 350 )

Custom range...

Search Results: 1 - 10 of 190046 matches for " G. Dupont-Nivet "
All listed articles are free for downloading (OA Articles)
Page 1 /190046
Display every page Item
Asian aridification linked to the first step of the Eocene-Oligocene climate Transition (EOT) in obliquity-dominated terrestrial records (Xining Basin, China)
G. Q. Xiao, H. A. Abels, Z. Q. Yao, G. Dupont-Nivet,F. J. Hilgen
Climate of the Past (CP) & Discussions (CPD) , 2010,
Abstract: Asian terrestrial records of the Eocene-Oligocene Transition (EOT) are rare and, when available, often poorly constrained in time, even though they are crucial in understanding the atmospheric impact of this major step in Cenozoic climate deterioration. Here, we present a detailed cyclostratigraphic study of the continuous continental EOT succession deposited between ~35 to 33 Ma in the Xining Basin at the northeastern edge of Tibetan Plateau. Lithology supplemented with high-resolution magnetic susceptibility (MS), median grain size (MGS) and color reflectance (a*) records reveal a prominent ~3.4 m thick basic cyclicity of alternating playa gypsum and dry mudflat red mudstones of latest Eocene age. The magnetostratigraphic age model indicates that this cyclicity was most likely forced by the 41-kyr obliquity cycle driving oscillations of drier and wetter conditions in Asian interior climate from at least 1 million year before the EOT. In addition, our results suggest a duration of ~0.9 Myr for magnetochron C13r that is in accordance with radiometric dates from continental successions in Wyoming, USA, albeit somewhat shorter than in current time scales. Detailed comparison of the EOT interval in the Tashan section with marine records suggest that the most pronounced lithofacies change in the Xining Basin corresponds to the first of two widely recognized steps in oxygen isotopes across the EOT. This first step precedes the major and second step (i.e. the base of Oi-1) and has recently been reported to be mainly related to atmospheric cooling rather than ice volume growth. Coincidence with lithofacies changes in our Chinese record would suggest that the atmospheric impact of the first step was of global significance, while the major ice volume increase of the second step did not significantly affect Asian interior climate.
Asian aridification linked to the first step of the Eocene-Oligocene climate Transition (EOT) in obliquity-dominated terrestrial records (Xining Basin, China)
G. Q. Xiao,H. A. Abels,Q. Z. Yao,G. Dupont-Nivet
Climate of the Past Discussions , 2010, DOI: 10.5194/cpd-6-627-2010
Abstract: Asian terrestrial records of the Eocene-Oligocene Transition (EOT) are rare and, when available, often poorly constrained in time, even though they are crucial in understanding the atmospheric impact of this major step in Cenozoic climate deterioration. Here, we present a detailed cyclostratigraphic study of the continuous continental EOT succession deposited between ~35 to 33 Ma in the Xining Basin at the northeastern edge of Tibetan Plateau. Lithology supplemented with high-resolution magnetic susceptibility (MS), median grain size (MGS) and color reflectance (a*) records reveal a prominent ~3.4 m thick basic cyclicity of alternating playa gypsum and dry mudflat red mudstones of latest Eocene age. The magnetostratigraphic age model indicates that this cyclicity was most likely forced by the 41-kyr obliquity cycle driving oscillations of drier and wetter conditions in Asian interior climate from at least 1 million year before the EOT. In addition, our results suggest a duration of ~0.9 Myr for magnetochron C13r that is in accordance with radiometric dates from continental successions in Wyoming, USA, albeit somewhat shorter than in current time scales. Detailed comparison of the EOT interval in the Tashan section with marine records suggest that the most pronounced lithofacies change in the Xining Basin corresponds to the first of two widely recognized steps in oxygen isotopes across the EOT. This first step precedes the major and second step (i.e. the base of Oi-1) and has recently been reported to be mainly related to atmospheric cooling rather than ice volume growth. Coincidence with lithofacies changes in our central Chinese record would suggest that the atmospheric impact of the first step was of global significance, while the major ice volume increase of the second step did not significantly affect Asian interior climate.
Paleoseismology of the Xorxol Segment of the Central Altyn Tagh Fault, Xinjiang, China
Z. Washburn,J. R. Arrowsmith,G. Dupont-Nivet,W. X. Feng
Annals of Geophysics , 2003, DOI: 10.4401/ag-3443
Abstract: Although the Altyn Tagh Fault (ATF) is thought to play a key role in accommodating India-Eurasian convergence, little is known about its earthquake history. Studies of this strike-slip fault are important for interpretation of the role of faulting versus distributed deformation in the accommodation of the India- Eurasia collision. In addition, the > 1200 km long fault represents one of the most important and exemplary intracontinental strike-slip faults in the world. We mapped fault trace geometry and interpreted paleoseismic trench exposures to characterize the seismogenic behavior of the ATF. We identified 2 geometric segment boundaries in a 270 km long reach of the central ATF. These boundaries define the westernmost Wuzhunxiao, the Central Pingding, and the easternmost Xorxol (also written as Suekuli or Suo erkuli) segments. In this paper, we present the results from the Camel paleoseismic site along the Xorxol Segment at 91.759°E, 38.919°N. There evidence for the last two earthquakes is clear and 14C dates from layers exposed in the excavation bracket their ages. The most recent earthquake occurred between 1456 and 1775 cal A.D. and the penultimate event was between 60 and 980 cal A.D. Combining the Camel interpretations with our published results for the central ATF, we conclude that multiple earthquakes with shorter rupture lengths (?? 50 km) rather than complete rupture of the Xorxol Segment better explain the paleoseismic data. We found 2-3 earthquakes in the last 2-3 kyr. When coupled with typical amounts of slip per event (5-10 m), the recurrence times are tentatively consistent with 1-2 cm/yr slip rates. This result favors models that consider the broader distribution of collisional deformation, rather than those with northward motion of India into Asia absorbed along a few faults bounding rigid blocks.
Quantitative genetics of growth traits in the edible snail, Helix aspersa Müller
M Dupont-Nivet, J Mallard, JC Bonnet, JM Blanc
Genetics Selection Evolution , 1997, DOI: 10.1186/1297-9686-29-5-571
Abstract:
Les escargots comestibles de C te d'Ivoire: effets de quelques plantes, d'aliments concentrés et de la teneur en calcium alimentaire sur la croissance d'Archachatina ventricosa (Gould, 1850) en élevage hors-sol en batiment
Otchoumou, A.,Dupont-Nivet, M.,Dosso, H.
Tropicultura , 2004,
Abstract: The Edible Ivorian Snails: Effects of Some Vegetables, Concentrated Diets and Dietary Calcium on the Growth of Archachatina ventricosa (Gould, 1850) in Indoor Rearing. Archachatina ventricosa (Gould) snails with 37.06 g body weight and 6.01 cm shell length were given two vegetable diets dialed with leaves of Lactuca sativa (Apiaceae) and Brassica oleracea (Brassicaceae) for R1, leaves of Laportea aestuans (Urticaceae) and Phaulopsis falcisepala (Acanthaceae) for R2 and four concentrated diets (RT, R3, R4 and R5) with variable calcium content (0.05%, 0.59%, 6.82%, 12.02%, 14.03% et 16.01% respectively) in order to determine the calcium content inducing the best growth and the cumulated mortality rate. This optimum calcium content was 16.01%. At higher calcium content, Archachatina ventricosa produced more shell than meat.
Microwave-stimulated Raman adiabatic passage in a Bose-Einstein condensate on an atom chip
Matthieu Dupont-Nivet,Mathias Casiulis,Théo Laudat,Christoph I. Westbrook,Sylvain Schwartz
Physics , 2015, DOI: 10.1103/PhysRevA.91.053420
Abstract: We report the achievement of stimulated Raman adiabatic passage (STIRAP) in the microwave frequency range between internal states of a Bose-Einstein condensate (BEC) magnetically trapped in the vicinity of an atom chip. The STIRAP protocol used in this experiment is robust to external perturbations as it is an adiabatic transfer, and power-efficient as it involves only resonant (or quasi-resonant) processes. Taking into account the effect of losses and collisions in a non-linear Bloch equations model, we show that the maximum transfer efficiency is obtained for non-zero values of the one- and two-photon detunings, which is confirmed quantitatively by our experimental measurements.
The Positive Impact of the Early-Feeding of a Plant-Based Diet on Its Future Acceptance and Utilisation in Rainbow Trout
Inge Geurden, Peter Borchert, Mukundh N. Balasubramanian, Johan W. Schrama, Mathilde Dupont-Nivet, Edwige Quillet, Sadasivam J. Kaushik, Stéphane Panserat, Fran?oise Médale
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0083162
Abstract: Sustainable aquaculture, which entails proportional replacement of fish-based feed sources by plant-based ingredients, is impeded by the poor growth response frequently seen in fish fed high levels of plant ingredients. This study explores the potential to improve, by means of early nutritional exposure, the growth of fish fed plant-based feed. Rainbow trout swim-up fry were fed for 3 weeks either a plant-based diet (diet V, V-fish) or a diet containing fishmeal and fish oil as protein and fat source (diet M, M-fish). After this 3-wk nutritional history period, all V- or M-fish received diet M for a 7-month intermediate growth phase. Both groups were then challenged by feeding diet V for 25 days during which voluntary feed intake, growth, and nutrient utilisation were monitored (V-challenge). Three isogenic rainbow trout lines were used for evaluating possible family effects. The results of the V-challenge showed a 42% higher growth rate (P = 0.002) and 30% higher feed intake (P = 0.005) in fish of nutritional history V compared to M (averaged over the three families). Besides the effects on feed intake, V-fish utilized diet V more efficiently than M-fish, as reflected by the on average 18% higher feed efficiency (P = 0.003). We noted a significant family effect for the above parameters (P<0.001), but the nutritional history effect was consistent for all three families (no interaction effect, P>0.05). In summary, our study shows that an early short-term exposure of rainbow trout fry to a plant-based diet improves acceptance and utilization of the same diet when given at later life stages. This positive response is encouraging as a potential strategy to improve the use of plant-based feed in fish, of interest in the field of fish farming and animal nutrition in general. Future work needs to determine the persistency of this positive early feeding effect and the underlying mechanisms.
Symmetric micro-wave potentials for interferometry with thermal atoms on a chip
M. Ammar,M. Dupont-Nivet,L. Huet,J. -P. Pocholle,P. Rosenbusch,I. Bouchoule,C. I. Westbrook,J. Estève,J. Reichel,C. Guerlin,S. Schwartz
Physics , 2014, DOI: 10.1103/PhysRevA.91.053623
Abstract: A trapped atom interferometer involving state-selective adiabatic potentials with two microwave frequencies on a chip is proposed. We show that this configuration provides a way to achieve a high degree of symmetry between the two arms of the interferometer, which is necessary for coherent splitting and recombination of thermal (i.e. non-condensed) atoms. The resulting interferometer holds promise to achieve high contrast and long coherence time, while avoiding the mean-field interaction issues of interferometers based on trapped Bose-Einstein condenstates.
Selection for Adaptation to Dietary Shifts: Towards Sustainable Breeding of Carnivorous Fish
Richard Le Boucher, Mathilde Dupont-Nivet, Marc Vandeputte, Thierry Kerne?s, Lionel Goardon, Laurent Labbé, Béatrice Chatain, Marie Josée Bothaire, Laurence Larroquet, Fran?oise Médale, Edwige Quillet
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0044898
Abstract: Genetic adaptation to dietary environments is a key process in the evolution of natural populations and is of great interest in animal breeding. In fish farming, the use of fish meal and fish oil has been widely challenged, leading to the rapidly increasing use of plant-based products in feed. However, high substitution rates impair fish health and growth in carnivorous species. We demonstrated that survival rate, mean body weight and biomass can be improved in rainbow trout (Oncorhynchus mykiss) after a single generation of selection for the ability to adapt to a totally plant-based diet (15.1%, 35.3% and 54.4%, respectively). Individual variability in the ability to adapt to major diet changes can be effectively used to promote fish welfare and a more sustainable aquaculture.
Caldero-Keller approach to the denominators of cluster variables
G. Dupont
Mathematics , 2007,
Abstract: Buan, Marsh and Reiten proved that if a cluster-tilting object $T$ in a cluster category $\mathcal C$ associated to an acyclic quiver $Q$ satisfies certain conditions with respect to the exchange pairs in $\mathcal C$, then the denominator in its reduced form of every cluster variable in the cluster algebra associated to $Q$ has exponents given by the dimension vector of the corresponding module over the endomorphism algebra of $T$. In this paper, we give an alternative proof of this result using the Caldero-Keller approach to acyclic cluster algebras and the work of Palu on cluster characters.
Page 1 /190046
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.