102 research outputs found
Cut-Based Graph Learning Networks to Discover Compositional Structure of Sequential Video Data
Conventional sequential learning methods such as Recurrent Neural Networks
(RNNs) focus on interactions between consecutive inputs, i.e. first-order
Markovian dependency. However, most of sequential data, as seen with videos,
have complex dependency structures that imply variable-length semantic flows
and their compositions, and those are hard to be captured by conventional
methods. Here, we propose Cut-Based Graph Learning Networks (CB-GLNs) for
learning video data by discovering these complex structures of the video. The
CB-GLNs represent video data as a graph, with nodes and edges corresponding to
frames of the video and their dependencies respectively. The CB-GLNs find
compositional dependencies of the data in multilevel graph forms via a
parameterized kernel with graph-cut and a message passing framework. We
evaluate the proposed method on the two different tasks for video
understanding: Video theme classification (Youtube-8M dataset) and Video
Question and Answering (TVQA dataset). The experimental results show that our
model efficiently learns the semantic compositional structure of video data.
Furthermore, our model achieves the highest performance in comparison to other
baseline methods.Comment: 8 pages, 3 figures, Association for the Advancement of Artificial
Intelligence (AAAI2020). arXiv admin note: substantial text overlap with
arXiv:1907.0170
DramaQA: Character-Centered Video Story Understanding with Hierarchical QA
Despite recent progress on computer vision and natural language processing,
developing video understanding intelligence is still hard to achieve due to the
intrinsic difficulty of story in video. Moreover, there is not a theoretical
metric for evaluating the degree of video understanding. In this paper, we
propose a novel video question answering (Video QA) task, DramaQA, for a
comprehensive understanding of the video story. The DramaQA focused on two
perspectives: 1) hierarchical QAs as an evaluation metric based on the
cognitive developmental stages of human intelligence. 2) character-centered
video annotations to model local coherence of the story. Our dataset is built
upon the TV drama "Another Miss Oh" and it contains 16,191 QA pairs from 23,928
various length video clips, with each QA pair belonging to one of four
difficulty levels. We provide 217,308 annotated images with rich
character-centered annotations, including visual bounding boxes, behaviors, and
emotions of main characters, and coreference resolved scripts. Additionally, we
provide analyses of the dataset as well as Dual Matching Multistream model
which effectively learns character-centered representations of video to answer
questions about the video. We are planning to release our dataset and model
publicly for research purposes and expect that our work will provide a new
perspective on video story understanding research.Comment: 21 pages, 10 figures, submitted to ECCV 202
Valosin-containing protein is a key mediator between autophagic cell death and apoptosis in adult hippocampal neural stem cells following insulin withdrawal
Background: Programmed cell death (PCD) plays essential roles in the regulation of survival and function of neural stem cells (NSCs). Abnormal regulation of this process is associated with developmental and degenerative neuronal disorders. However, the mechanisms underlying the PCD of NSCs remain largely unknown. Understanding the mechanisms of PCD in NSCs is crucial for exploring therapeutic strategies for the treatment of neurodegenerative diseases. Result: We have previously reported that adult rat hippocampal neural stem (HCN) cells undergo autophagic cell death (ACD) following insulin withdrawal without apoptotic signs despite their normal apoptotic capabilities. It is unknown how interconnection between ACD and apoptosis is mediated in HCN cells. Valosin-containing protein (VCP) is known to be essential for autophagosome maturation in mammalian cells. VCP is abundantly expressed in HCN cells compared to hippocampal tissue and neurons. Pharmacological and genetic inhibition of VCP at basal state in the presence of insulin modestly impaired autophagic flux, consistent with its known role in autophagosome maturation. Of note, VCP inaction in insulin-deprived HCN cells significantly decreased ACD and down-regulated autophagy initiation signals with robust induction of apoptosis. Overall autophagy level was also substantially reduced, suggesting the novel roles of VCP at initial step of autophagy. Conclusion: Taken together, these data demonstrate that VCP may play an essential role in the initiation of autophagy and mediation of crosstalk between ACD and apoptosis in HCN cells when autophagy level is high upon insulin withdrawal. This is the first report on the role of VCP in regulation of NSC cell death. Elucidating the mechanism by which VCP regulates the crosstalk of ACD and apoptosis will contribute to understanding the molecular mechanism of PCD in NSCs. © 2016 Yeo et al.1
Metformin Attenuates Experimental Autoimmune Arthritis through Reciprocal Regulation of Th17/Treg Balance and Osteoclastogenesis
Central Pain from Excitotoxic Spinal Cord Injury Induced by Intraspinal NMDA Injection: A Pilot Study
GSK3B induces autophagy by phosphorylating ULK1
Unc-51-like autophagy activating kinase 1 (ULK1), a mammalian homolog of the yeast kinase Atg1, has an essential role in autophagy induction. In nutrient and growth factor signaling, ULK1 activity is regulated by various posttranslational modifications, including phosphorylation, acetylation, and ubiquitination. We previously identified glycogen synthase kinase 3 beta (GSK3B) as an upstream regulator of insulin withdrawal-induced autophagy in adult hippocampal neural stem cells. Here, we report that following insulin withdrawal, GSK3B directly interacted with and activated ULK1 via phosphorylation of S405 and S415 within the GABARAP-interacting region. Phosphorylation of these residues facilitated the interaction of ULK1 with MAP1LC3B and GABARAPL1, while phosphorylation-defective mutants of ULK1 failed to do so and could not induce autophagy flux. Furthermore, high phosphorylation levels of ULK1 at S405 and S415 were observed in human pancreatic cancer cell lines, all of which are known to exhibit high levels of autophagy. Our results reveal the importance of GSK3B-mediated phosphorylation for ULK1 regulation and autophagy induction and potentially for tumorigenesis. © 2021, The Author(s).1
Effect of a Dual Drug-Coated Stent With Abciximab and Alpha-Lipoic Acid in a Porcine Coronary Restenosis Model
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