1,851 research outputs found

    Strong density for higher order Sobolev spaces into compact manifolds

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    Given a compact manifold NnN^n, an integer k∈N∗k \in \mathbb{N}_* and an exponent 1≤p<∞1 \le p < \infty, we prove that the class C∞(Q‾m;Nn)C^\infty(\overline{Q}^m; N^n) of smooth maps on the cube with values into NnN^n is dense with respect to the strong topology in the Sobolev space Wk,p(Qm;Nn)W^{k, p}(Q^m; N^n) when the homotopy group π⌊kp⌋(Nn)\pi_{\lfloor kp \rfloor}(N^n) of order ⌊kp⌋\lfloor kp \rfloor is trivial. We also prove the density of maps that are smooth except for a set of dimension m−⌊kp⌋−1m - \lfloor kp \rfloor - 1, without any restriction on the homotopy group of $N^n

    The bud break process and its variation among local populations of boreal black spruce

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    Phenology of local populations can exhibit adaptations to the current environmental conditions resulting from a close interaction between climate and genotype. The bud break process and its variations among populations were analyzed in greenhouse by monitoring the growth resumption in black spruce [Picea mariana (Mill.) BSP] seedlings originating from seeds of five stands across the closed boreal forest in Quebec, Canada. Bud break lasted 15 days and occurred earlier and quicker in northern provenances. Provenance explained between 10.2 and 32.3% of the variance in bud break, while the families accounted for a smaller but still significant part of the variance. The late occurrence of one phenological phase corresponded to a delayed occurrence of the others according to linear relationships. A causal model was proposed in the form of a chain of events with each phase of bud break being related to the previous and successive one, while no link was observed between non-adjacent phases. The adaptation of black spruce populations along the latitudinal gradient points toward a strategy based on rapid physiological processes triggered by temperature increase inducing high metabolic activity. The variation observed in bud break reflects an evolutionary trade-off between maximization of security and taking advantage of the short growing season. This work provides evidence of the phenological adaptations of black spruce to its local environmental conditions while retaining sizeable genetic diversity within populations. Because of the multigenic nature of phenology, this diversity should provide some raw material for adaptation to changing local environmental conditions

    ARIA-EAACI statement on asthma and COVID-19 (June 2, 2020)

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    Artículo con numerosos autores sólo se mencionan el primero y el de la UAMOpen access funding enabled and organized by Projekt DEA

    Typicality extraction in a Speaker Binary Keys model

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    International audienceIn the field of speaker recognition, the recently proposed notion of "Speaker Binary Key" provides a representation of each acoustic frame in a discriminant binary space. This approach relies on an unique acoustic model composed by a large set of speaker specific local likelihood peaks (called specificities). The model proposes a spatial coverage where each frame is characterized in terms of neighborhood. The most frequent specificities, picked up to represent the whole utterance, generate a binary key vector. The flexibility of this modeling allows to capture non-parametric behaviors. In this paper, we introduce a concept of "typicality" between binary keys, with a discriminant goal. We describe an algorithm able to extract such typicalities, which involves a singular value decomposition in a binary space. The theoretical aspects of this decomposition as well as its potential in terms of future developments are presented. All the propositions are also experimentally validated using NIST SRE 2008 framework
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