2,465 research outputs found

    A genome-wide investigation of the worldwide invader Sargassum muticum shows high success albeit (almost) no genetic diversity

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    Twenty years of genetic studies of marine invaders have shown that successful invaders are often characterized by native and introduced populations displaying similar levels of genetic diversity. This pattern is presumably due to high propagule pressure and repeated introductions. The opposite pattern is reported in this study of the brown seaweed, Sargassum muticum, an emblematic species for circumglobal invasions. Albeit demonstrating polymorphism in the native range, microsatellites failed to detect any genetic variation over 1,269 individuals sampled from 46 locations over the Pacific-Atlantic introduction range. Single-nucleotide polymorphisms (SNPs) obtained from ddRAD sequencing revealed some genetic variation, but confirmed severe founder events in both the Pacific and Atlantic introduction ranges. Our study thus exemplifies the need for extreme caution in interpreting neutral genetic diversity as a proxy for invasive potential. Our results confirm a previously hypothesized transoceanic secondary introduction from NE Pacific to Europe. However, the SNP panel unexpectedly revealed two additional distinct genetic origins of introductions. Also, conversely to scenarios based on historical records, southern rather than northern NE Pacific populations could have seeded most of the European populations. Finally, the most recently introduced populations showed the lowest selfing rates, suggesting higher levels of recombination might be beneficial at the early stage of the introduction process (i.e., facilitating evolutionary novelties), whereas uniparental reproduction might be favored later in sustainably established populations (i.e., sustaining local adaptation).Agence Nationale de la Recherche - ANR-10-BTBR-04; European Regional Development Fund; Fundacao para a Ciencia e a Tecnologia - SFRH/BPD/107878/2015, UID/Multi/04326/2016, UID/Multi/04326/2019; Brittany Region;info:eu-repo/semantics/publishedVersio

    Comparison of Information Structures and Completely Positive Maps

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    A theorem of Blackwell about comparison between information structures in classical statistics is given an analogue in the quantum probabilistic setup. The theorem provides an operational interpretation for trace-preserving completely positive maps, which are the natural quantum analogue of classical stochastic maps. The proof of the theorem relies on the separation theorem for convex sets and on quantum teleportation.Comment: 12 pages. Substantial changes. Accepted for publication in Journal of Physics

    Asymptotically optimal quantum channel reversal for qudit ensembles and multimode Gaussian states

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    We investigate the problem of optimally reversing the action of an arbitrary quantum channel C which acts independently on each component of an ensemble of n identically prepared d-dimensional quantum systems. In the limit of large ensembles, we construct the optimal reversing channel R* which has to be applied at the output ensemble state, to retrieve a smaller ensemble of m systems prepared in the input state, with the highest possible rate m/n. The solution is found by mapping the problem into the optimal reversal of Gaussian channels on quantum-classical continuous variable systems, which is here solved as well. Our general results can be readily applied to improve the implementation of robust long-distance quantum communication. As an example, we investigate the optimal reversal rate of phase flip channels acting on a multi-qubit register.Comment: 17 pages, 3 figure

    Fisher information and asymptotic normality in system identification for quantum Markov chains

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    This paper deals with the problem of estimating the coupling constant θ\theta of a mixing quantum Markov chain. For a repeated measurement on the chain's output we show that the outcomes' time average has an asymptotically normal (Gaussian) distribution, and we give the explicit expressions of its mean and variance. In particular we obtain a simple estimator of θ\theta whose classical Fisher information can be optimized over different choices of measured observables. We then show that the quantum state of the output together with the system, is itself asymptotically Gaussian and compute its quantum Fisher information which sets an absolute bound to the estimation error. The classical and quantum Fisher informations are compared in a simple example. In the vicinity of θ=0\theta=0 we find that the quantum Fisher information has a quadratic rather than linear scaling in output size, and asymptotically the Fisher information is localised in the system, while the output is independent of the parameter.Comment: 10 pages, 2 figures. final versio

    Protective action of taurine, given as a pretreatment or as a posttreatment, against endotoxin-induced acute lung inflammation in hamsters

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    To assess the effect of taurine on lipopolysaccharide (LPS)-induced lung inflammation, oxidative stress and apoptosis, female Golden Syrian hamsters were intratracheally instilled with bacterial LPS (0.02 mg in phosphate buffered saline (PBS) pH 7.4), before or after a 3-day intraperitoneal treatment with a single dose of taurine (50 mg/kg/day in PBS pH 7.4), and bronchoalveolar lavage fluid (BALF) and lung tissue samples were collected at 24 hr after the last treatment. In comparison to BALF samples from animals receiving only PBS pH 7.4, and serving as controls, those of LPS-stimulated animals exhibited a higher count of both total leukocytes and neutrophils and increased expression of tumor necrosis factor receptor 1. In comparison to lungs from control animals, those from LPS-treated animals showed increased cellular apoptosis, lipid peroxidation, decreased glutathione levels, altered activities of antioxidant enzymes (catalase, glutathione peroxidase, superoxide dismutase) and focal inflammation confined to the parenchyma. A treatment with taurine was found to significantly attenuate all these alterations, with the protection being, in all instances, greater when given before rather than after LPS. The present results suggest that taurine is endowed with antiinflammatory and antioxidant properties that are protective in the lung against the deleterious actions of Gram negative bacterial endotoxin

    Derived categories of Burniat surfaces and exceptional collections

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    We construct an exceptional collection Υ\Upsilon of maximal possible length 6 on any of the Burniat surfaces with KX2=6K_X^2=6, a 4-dimensional family of surfaces of general type with pg=q=0p_g=q=0. We also calculate the DG algebra of endomorphisms of this collection and show that the subcategory generated by this collection is the same for all Burniat surfaces. The semiorthogonal complement A\mathcal A of Υ\Upsilon is an "almost phantom" category: it has trivial Hochschild homology, and K_0(\mathcal A)=\bZ_2^6.Comment: 15 pages, 1 figure; further remarks expande

    A Christian Guide to Body Stewardship, Diet and Exercise - 3rd Edition

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    This free textbook provides readers with a wealth of practical information regarding body stewardship, nutrition, and exercise, all written from a Christian worldview. While other textbooks provide readers with the why proper nutrition and regular exercise is important, this textbook takes it one step further and provides readers with the how . Each chapter is filled with helpful charts, tables, and figures that equip readers with tangible resources and recommendations they can use to put into practice the various concepts being introduced. Additionally, each chapter is written from a Christian worldview recognizing that the human body was created for a purpose, and through Godly stewardship of our bodies, we can more effectively worship our creator.https://digitalcommons.cedarville.edu/cedrus_press_publications/1024/thumbnail.jp

    Motor and higher‐order functions topography of the human dentate nuclei identified with tractography and clustering methods

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    Deep gray matter nuclei are the synaptic relays, responsible to route signals between specific brain areas. Dentate nuclei (DNs) represent the main output channel of the cerebellum and yet are often unexplored especially in humans. We developed a multimodal MRI approach to identify DNs topography on the basis of their connectivity as well as their microstructural features. Based on results, we defined DN parcellations deputed to motor and to higher-order functions in humans in vivo. Whole-brain probabilistic tractography was performed on 25 healthy subjects from the Human Connectome Project to infer DN parcellations based on their connectivity with either the cerebral or the cerebellar cortex, in turn. A third DN atlas was created inputting microstructural diffusion-derived metrics in an unsupervised fuzzy c-means classification algorithm. All analyses were performed in native space, with probability atlas maps generated in standard space. Cerebellar lobule-specific connectivity identified one motor parcellation, accounting for about 30% of the DN volume, and two non-motor parcellations, one cognitive and one sensory, which occupied the remaining volume. The other two approaches provided overlapping results in terms of geometrical distribution with those identified with cerebellar lobule-specific connectivity, although with some differences in volumes. A gender effect was observed with respect to motor areas and higher-order function representations. This is the first study that indicates that more than half of the DN volumes is involved in non-motor functions and that connectivity-based and microstructure-based atlases provide complementary information. These results represent a step-ahead for the interpretation of pathological conditions involving cerebro-cerebellar circuits

    Simpósio Nacional de Culturas Agro-industriais Potencialidades e perspectivas

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    Simpósio Nacional de Culturas Agro-industriais Potencialidades e perspectiva

    Data-driven efficient score tests for deconvolution problems

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    We consider testing statistical hypotheses about densities of signals in deconvolution models. A new approach to this problem is proposed. We constructed score tests for the deconvolution with the known noise density and efficient score tests for the case of unknown density. The tests are incorporated with model selection rules to choose reasonable model dimensions automatically by the data. Consistency of the tests is proved
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