Effect of trap symmetry and atom-atom interactions on a trapped atom interferometer with internal state labelling

In this paper, we study the dynamics of a trapped atom interferometer with internal state labelling in the presence of interactions. We consider two situations: an atomic clock in which the internal states remain superposed, and an inertial sensor configuration in which they are separated. From the average spin evolution, we deduce the fringe contrast and the phase-shift. In the clock configuration, we recover the well-known identical spin rotation effect (ISRE) which can significantly increase the spin coherence time. We also find that the magnitude of the effect depends on the trap geometry in a way that is consistent with our recent experimental results in a clock configuration [M. Dupont-Nivet, and al., New J. Phys., 20, 043051 (2018)], where ISRE was not observed. In the case of an inertial sensor, we show that despite the spatial separation it is still possible to increase the coherence time by using mean field interactions to counteract asymmetries of the trapping potential.Comment: 18 pages, 5 figure

Quantitative genetics of growth traits in the edible snail, Helix aspersa Müller

Genetic parameters of adult weight, age at maturity (adult age), weight after hibernation and relative loss of weight during hibernation were estimated in a population of edible snails (Helix aspersa Müller). Eight thousand four hundred and eighthy three animals were sampled from 143 pairs for adult weight, 4 333 from 87 pairs for adult age and 2 256 from 123 pairs for traits after hibernation. An animal model taking into account all the relationships was used to estimate genetic parameters. Estimates were also computed from the covariances between full-sibs and parent offspring regressions to assess possible non-additive genetic effects. Heritabilities were high except for relative loss of weight during hibernation. Estimates from the animal model were 0.48 ± 0.04 for adult weight, 0.40 ± 0.05 for adult age, 0.40 ± 0.05 for weight after hibernation and 0.12 ± 0.03 for relative loss of weight during hibernation. Adult weight and adult age were neither phenotypically nor genetically correlated (0.05 and 0.003 ± 0.07, respectively). A substantial maternal effect, especially on adult weight was found.Les paramètres génétiques de plusieurs caractères de croissance ont été estimés dans une population d’escargots Petit-Gris (Helix aspersa Müller). Il s’agit du poids adulte, de l’âge à maturité (âge adulte), du poids après hibernation et de la perte relative de poids lors de l’hibernation. Le nombre d’observations collectées se répartit ainsi : 8 483 animaux issus de 143 couples pour le poids adulte, 4 333 issus de 87 couples pour l’âge adulte et 2 256 issus de 123 couples pour les caractères mesurés après hibernation. Afin de tenir compte de toutes les relations de parenté, nous avons utilisé un modèle animal pour estimer les paramètres génétiques. Ils ont également été estimés à partir des covariances entre plein-frères et de la régression parents-descendants. Cela nous a permis de discuter des effets génétiques non additifs. Tous les caractères sauf la perte de poids relative lors de l’hibernation révèlent des héritabilités élevées. Les estimations issues du modèle animal sont de 0,48 ± 0,04 pour le poids adulte, 0,40 ± 0,05 pour l’âge adulte, 0,40 ± 0,05 pour le poids après hibernation et 0, 12 ± 0 03 pour la perte relative de poids lors de l’hibernation. Il n’y a pas de corrélation (ni phénotypique, ni génétique) significative entre le poids et l’âge adultes (0,05 et 0,003 ± 0,07, respectivement). Nous avons également mis en évidence un effet maternel important, en particulier sur le poids adulte

The Positive Impact of the Early-Feeding of a Plant-Based Diet on Its Future Acceptance and Utilisation in Rainbow Trout

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 swimup 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 shortterm 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

Asian monsoons and aridification response to Paleogene sea retreat and Neogene westerly shielding indicated by seasonality in Paratethys oysters

Asian climate patterns, characterised by highly seasonal monsoons and continentality, are thought to originate in the Eocene epoch (56 to 34 million years ago – Ma) in response to global climate, Tibetan Plateau uplift and the disappearance of the giant Proto-Paratethys sea formerly extending over Eurasia. The influence of this sea on Asian climate has hitherto not been constrained by proxy records despite being recognised as a major driver by climate models. We report here strongly seasonal records preserved in annual lamina of Eocene oysters from the Proto-Paratethys with sedimentological and numerical data showing that monsoons were not dampened by the sea and that aridification was modulated by westerly moisture sourced from the sea. Hot and arid summers despite the presence of the sea suggest a strong anticyclonic zone at Central Asian latitudes and an orographic effect from the emerging Tibetan Plateau. Westerly moisture precipitating during cold and wetter winters appear to have decreased in two steps. First in response to the late Eocene (34–37 Ma) sea retreat; second by the orogeny of the Tian Shan and Pamir ranges shielding the westerlies after 25 Ma. Paleogene sea retreat and Neogene westerly shielding thus provide two successive mechanisms forcing coeval Asian desertification and biotic crises