110 research outputs found

    Speaker Recognition Using Isomorphic Graph Attention Network Based Pooling on Self-Supervised Representation

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    The emergence of self-supervised representation (i.e., wav2vec 2.0) allows speaker-recognition approaches to process spoken signals through foundation models built on speech data. Nevertheless, effective fusion on the representation requires further investigating, due to the inclusion of fixed or sub-optimal temporal pooling strategies. Despite of improved strategies considering graph learning and graph attention factors, non-injective aggregation still exists in the approaches, which may influence the performance for speaker recognition. In this regard, we propose a speaker recognition approach using Isomorphic Graph ATtention network (IsoGAT) on self-supervised representation. The proposed approach contains three modules of representation learning, graph attention, and aggregation, jointly considering learning on the self-supervised representation and the IsoGAT. Then, we perform experiments for speaker recognition tasks on VoxCeleb1\&2 datasets, with the corresponding experimental results demonstrating the recognition performance for the proposed approach, compared with existing pooling approaches on the self-supervised representation.Comment: 9 pages, 4 figure

    HPLC-based activity profiling for GABAA receptor modulators from the traditional Chinese herbal drug Kushen ( Sophora flavescens root)

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    An EtOAc extract from the roots of Sophora flavescens (Kushen) potentiated γ-aminobutyric acid (GABA)-induced chloride influx in Xenopus oocytes transiently expressing GABAA receptors with subunit composition, α 1 β 2 γ 2S. HPLC-based activity profiling of the extract led to the identification of 8-lavandulyl flavonoids, kushenol I, sophoraflavanone G, (−)-kurarinone, and kuraridine as GABAA receptor modulators. In addition, a series of inactive structurally related flavonoids were characterized. Among these, kushenol Y (4) was identified as a new natural product. The 8-lavandulyl flavonoids are first representatives of a novel scaffold for the targe

    Anderson Localization from Berry-Curvature Interchange in Quantum Anomalous Hall System

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    We theoretically investigate the localization mechanism of the quantum anomalous Hall effect (QAHE) in the presence of spin-flip disorders. We show that the QAHE keeps quantized at weak disorders, then enters a Berry-curvature mediated metallic phase at moderate disorders, and finally goes into the Anderson insulating phase at strong disorders. From the phase diagram, we find that at the charge neutrality point although the QAHE is most robust against disorders, the corresponding metallic phase is much easier to be localized into the Anderson insulating phase due to the \textit{interchange} of Berry curvatures carried respectively by the conduction and valence bands. At the end, we provide a phenomenological picture related to the topological charges to better understand the underlying physical origin of the QAHE Anderson localization.Comment: 6 pages, 4 figure

    Antidiabetic Activity of a Flavonoid-Rich Extract From Sophora davidii (Franch.) Skeels in KK-Ay Mice via Activation of AMP-Activated Protein Kinase

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    The present study was undertaken to investigate the hypoglycemic activity and potential mechanisms of action of a flavonoid-rich extract from Sophora davidii (Franch.) Skeels (SD-FRE) through in vitro and in vivo studies. Four main flavonoids of SD-FRE namely apigenin, maackiain, leachianone A and leachianone B were purified and identified. In vitro, SD-FRE significantly promoted the translocation and expression of glucose transporter 4 (GLUT4) in L6 cells, which was significantly inhibited by Compound C (AMPK inhibitor), but not by Wortmannin (PI3K inhibitor) or Gö6983 (PKC inhibitor). These results indicated that SD-FRE enhanced GLUT4 expression and translocation to the plasma membrane via the AMPK pathway and finally resulted in an increase of glucose uptake. In vivo, using a spontaneously type 2 diabetic model, KK-Ay mice received intragastric administration of SD-FRE for 4 weeks. As a consequence, SD-FRE significantly alleviated the hyperglycemia, glucose intolerance, insulin resistance and hyperlipidemia in these mice. Hepatic steatosis, islet hypertrophy and larger adipocyte size were observed in KK-Ay mice. However, these pathological changes were effectively relieved by SD-FRE treatment. SD-FRE promoted GLUT4 expression and activated AMPK phosphorylation in insulin target tissues (muscle, adipose tissue and liver) of KK-Ay mice, thus facilitating glucose utilization to ameliorate insulin resistance. Regulation of ACC phosphorylation and PPARγ were also involved in the antidiabetic effects of SD-FRE. Taken together, these findings indicated that SD-FRE has the potential to alleviate type 2 diabetes

    De quelques catéchismes créoles anciens: oublis, pertes, disparitions, réapparitions, découvertes

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    Il existe, dans le très vaste domaine des études postcoloniales, des territoires contigus ou semblables qui connaissent des phénomènes communs mais aux histoires très différentes, sinon radicalement opposées : tels les catéchismes - en langues romanes - fruit de la colonisation. Plus précisément, à l’histoire des catéchismes issus de la colonisation hispano-américaine, s’oppose l’histoire des catéchismes issus de la colonisation française, de l’Amérique et d’ailleurs. Ces derniers arrivent un siècle et demi environ après les espagnols et se manifestent de tout autre manière ; différents en sont l’époque, la scène et les acteurs : les destinateurs mais surtout les destinataires. Ce travail se propose de retracer l’histoire souvent aventureuse des plus anciens catéchismes des colonies ou ex-colonies françaises de la Caraïbe et de l’Océan Indien ; écrits en créole ou, parfois, en d’autres langues autochtones, ils constituent aussi des témoignages linguistiques absolument précieux. Rédigés généralement sur place, mais non toujours publiés, leur histoire est faite d’oublis, pertes, disparitions, réapparitions et découvertes. - - - In the wide field of postcolonial studies, there exist related or similar areas whose stories are nevertheless very different, if not indeed opposed. This is the case of catechisms in Romance languages (or of Romance origin), outcomes of European colonization. In particular, contradictions between the history of catechisms from Hispanic-American colonization and the catechisms produced by French colonization, in America and elsewhere. The latter appear a century and a half after the Spanish texts, and exhibit completely distinct characteristics: different periods, settings, actors, and especially recipients. I set out to recount the often adventurous history of the oldest catechisms in the French colonies, or ex-colonies, of the Caribbean and the Indian Ocean. Written in Creole or sometimes other indigenous languages, they are precious linguistic records. Compiled in the colonies, but not always published, these texts are often forgotten, lost, misplaced, resurfaced, discovered
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