2,429 research outputs found

    Augmented 2D-TAN: A Two-stage Approach for Human-centric Spatio-Temporal Video Grounding

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    We propose an effective two-stage approach to tackle the problem of language-based Human-centric Spatio-Temporal Video Grounding (HC-STVG) task. In the first stage, we propose an Augmented 2D Temporal Adjacent Network (Augmented 2D-TAN) to temporally ground the target moment corresponding to the given description. Primarily, we improve the original 2D-TAN from two aspects: First, a temporal context-aware Bi-LSTM Aggregation Module is developed to aggregate clip-level representations, replacing the original max-pooling. Second, we propose to employ Random Concatenation Augmentation (RCA) mechanism during the training phase. In the second stage, we use pretrained MDETR model to generate per-frame bounding boxes via language query, and design a set of hand-crafted rules to select the best matching bounding box outputted by MDETR for each frame within the grounded moment.Comment: Best Paper Award at the 3rd Person in Context (PIC) Challenge CVPR Workshop 202

    GitNet: Geometric Prior-based Transformation for Birds-Eye-View Segmentation

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    Birds-eye-view (BEV) semantic segmentation is critical for autonomous driving for its powerful spatial representation ability. It is challenging to estimate the BEV semantic maps from monocular images due to the spatial gap, since it is implicitly required to realize both the perspective-to-BEV transformation and segmentation. We present a novel two-stage Geometry Prior-based Transformation framework named GitNet, consisting of (i) the geometry-guided pre-alignment and (ii) ray-based transformer. In the first stage, we decouple the BEV segmentation into the perspective image segmentation and geometric prior-based mapping, with explicit supervision by projecting the BEV semantic labels onto the image plane to learn visibility-aware features and learnable geometry to translate into BEV space. Second, the pre-aligned coarse BEV features are further deformed by ray-based transformers to take visibility knowledge into account. GitNet achieves the leading performance on the challenging nuScenes and Argoverse Datasets. The code will be publicly available

    Major Population Expansion of East Asians Began before Neolithic Time: Evidence of mtDNA Genomes

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    It is a major question in archaeology and anthropology whether human populations started to grow primarily after the advent of agriculture, i.e., the Neolithic time, especially in East Asia, which was one of the centers of ancient agricultural civilization. To answer this question requires an accurate estimation of the time of lineage expansion as well as that of population expansion in a population sample without ascertainment bias. In this study, we analyzed all available mtDNA genomes of East Asians ascertained by random sampling, a total of 367 complete mtDNA sequences generated by the 1000 Genome Project, including 249 Chinese (CHB, CHD, and CHS) and 118 Japanese (JPT). We found that major mtDNA lineages underwent expansions, all of which, except for two JPT-specific lineages, including D4, D4b2b, D4a, D4j, D5a2a, A, N9a, F1a1'4, F2, B4, B4a, G2a1 and M7b1'2'4, occurred before 10 kya, i.e., before the Neolithic time (symbolized by Dadiwan Culture at 7.9 kya) in East Asia. Consistent to this observation, the further analysis showed that the population expansion in East Asia started at 13 kya and lasted until 4 kya. The results suggest that the population growth in East Asia constituted a need for the introduction of agriculture and might be one of the driving forces that led to the further development of agriculture

    Observations on Copy Number Variations in a Kidney-yang Deficiency Syndrome Family

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    We have performed an analysis of a family with kidney-yang deficiency syndrome (KDS) in order to determine the structural genomic variations through a novel approach designated as “copy number variants” (CNVs). Twelve KDS subjects and three healthy spouses from this family were included in this study. Genomic DNA samples were genotyped utilizing an Affymetrix 100 K single nucleotide polymorphism array, and CNVs were identified by Copy Number Algorithm (CNAT4.0, Affymetrix). Our results demonstrate that 447 deleted and 476 duplicated CNVs are shared among KDS subjects within the family. The homologus ratio of deleted CNVs was as high as 99.78%. One-copy-duplicated CNVs display mid-range homology. For two copies of duplicated CNVs (CNV4), a markedly heterologous ratio was observed. Therefore, with the important exception of CNV4, our data shows that CNVs shared among KDS subjects display typical Mendelian inheritance. A total of 113 genes with established functions were identified from the CNV flanks; significantly enriched genes surrounding CNVs may contribute to certain adaptive benefit. These genes could be classified into categories including: binding and transporter, cell cycle, signal transduction, biogenesis, nerve development, metabolism regulation and immune response. They can also be included into three pathways, that is, signal transduction, metabolic processes and immunological networks. Particularly, the results reported here are consistent with the extensive impairments observed in KDS patients, involving the mass-energy-information-carrying network. In conclusion, this article provides the first set of CNVs from KDS patients that will facilitate our further understanding of the genetic basis of KDS and will allow novel strategies for a rational therapy of this disease

    Low-mass dark matter search results from full exposure of PandaX-I experiment

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    We report the results of a weakly-interacting massive particle (WIMP) dark matter search using the full 80.1\;live-day exposure of the first stage of the PandaX experiment (PandaX-I) located in the China Jin-Ping Underground Laboratory. The PandaX-I detector has been optimized for detecting low-mass WIMPs, achieving a photon detection efficiency of 9.6\%. With a fiducial liquid xenon target mass of 54.0\,kg, no significant excess event were found above the expected background. A profile likelihood analysis confirms our earlier finding that the PandaX-I data disfavor all positive low-mass WIMP signals reported in the literature under standard assumptions. A stringent bound on the low mass WIMP is set at WIMP mass below 10\,GeV/c2^2, demonstrating that liquid xenon detectors can be competitive for low-mass WIMP searches.Comment: v3 as accepted by PRD. Minor update in the text in response to referee comments. Separating Fig. 11(a) and (b) into Fig. 11 and Fig. 12. Legend tweak in Fig. 9(b) and 9(c) as suggested by referee, as well as a missing legend for CRESST-II legend in Fig. 12 (now Fig. 13). Same version as submitted to PR

    Emerging technologies for conversion of sustainable macroalgal carrageenan biomass into L-lactic acid: A state-of-the-art review

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    The environmental awareness and concerns (plastic pollution) worldwide have driven the development of sustainable and environmentally friendly biopolymer derived from renewable materials. Biopolymers, especially L-lactic acid (L-LA) have played a crucial role in manufacturing polylactic acid, a biodegradable thermoplastic. Recently, L-LA production from non-edible macroalgal biomass has gained immense attraction due to it offers the simplest saccharification process for the biorefinery route. However, the commercialization of macroalgal-based L-LA is still limited due to high production costs. This paper has comprehensively reviewed the potential and development of third-generation feedstock for L-LA production, including significant technological barriers to be overcome for potential commercialization purposes. Then, an insight into the state-of-the-art hydrolysis and fermentation technologies using macroalgae as feedstock are also deliberated in detail. Furthermore, this review provides a conceivable picture of macroalgae-based L-LA biorefinery and future research directions that can be served as an important guideline for scientists, policymakers, and industrial players

    Coexistence of superconductivity with exotic ferromagnetic state in pressurized non-superconducting UTe2_2

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    The discovery of superconductivity in heavy Fermion UTe2_2, a candidate topological and triplet-paired superconductor, has aroused widespread interest. However, to date, superconductivity has only been reported in nonstoichiometric crystals of UTe2_2 with a Te deficit. Here, we demonstrate that the application of uniaxial pressure induces superconductivity in stoichiometric UTe2_2 crystals. Measurements of resistivity, magnetoresistance and susceptibility reveal that uniaxial pressure results in a suppression of the Kondo coherent state seen at ambient pressure, leading to the emergence of superconductivity initially at 1.5 GP, followed by the development of bulk superconductivity at 4.8 GPa. The superconducting state coexists with an exotic ferromagnetically ordered (FM) state that develops just below the onset temperature of the superconducting transition. High-pressure synchrotron x-ray diffraction measurements performed at 20 K indicate that no structural phase transition occurs over the measured pressure range. Our results not only demonstrate the coexistence of superconductivity with an exotic ferromagnetic state in pressurized stoichiometric UTe2_2, but also highlight a vital role of Te deficiency in developing superconductivity at ambient pressures.Comment: 17 pages, 4 figure

    Role of hypoxia-inducible factors in epigenetic regulation via histone demethylases.

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    Eukaryotic chromatin is subject to multiple posttranslational histone modifications such as acetylation, methylation, phosphorylation, and ubiquitination. These various covalent modifications have been proposed to constitute a "histone code," playing important roles in the establishment of global chromatin environments, transcription, DNA repair, and DNA replication. Among these modifications, histone methylation specifies regulatory marks that delineate transcriptionally active and inactive chromatin. These histone methyl marks were considered irreversible; however, recent identification of site-specific histone demethylases demonstrates that histone methylation is dynamically regulated, which may allow cells to rapidly change chromatin conformation to adapt to environmental stresses or intrinsic stimuli. Of major interest is the observation that these histone demethylase enzymes, which are in the Jumonji gene family, require oxygen to function and, in some cases, are induced by hypoxia in an HIFalpha-dependent manner. This provides a new mechanism for regulation of the response to hypoxia
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