7 results on '"Xuena Chen"'
Search Results
2. SA‐FlowNet: Event‐based self‐attention optical flow estimation with spiking‐analogue neural networks
- Author
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Fan Yang, Li Su, Jinxiu Zhao, Xuena Chen, Xiangyu Wang, Na Jiang, and Quan Hu
- Subjects
computer vision ,feature extraction ,motion estimation ,optical tracking ,Computer applications to medicine. Medical informatics ,R858-859.7 ,Computer software ,QA76.75-76.765 - Abstract
Abstract Inspired by biological vision mechanism, event‐based cameras have been developed to capture continuous object motion and detect brightness changes independently and asynchronously, which overcome the limitations of traditional frame‐based cameras. Complementarily, spiking neural networks (SNNs) offer asynchronous computations and exploit the inherent sparseness of spatio‐temporal events. Notably, event‐based pixel‐wise optical flow estimations calculate the positions and relationships of objects in adjacent frames; however, as event camera outputs are sparse and uneven, dense scene information is difficult to generate and the local receptive fields of the neural network also lead to poor moving objects tracking. To address these issues, an improved event‐based self‐attention optical flow estimation network (SA‐FlowNet) that independently uses criss‐cross and temporal self‐attention mechanisms, directly capturing long‐range dependencies and efficiently extracting the temporal and spatial features from the event streams is proposed. In the former mechanism, a cross‐domain attention scheme dynamically fusing the temporal‐spatial features is introduced. The proposed network adopts a spiking‐analogue neural network architecture using an end‐to‐end learning method and gains significant computational energy benefits especially for SNNs. The state‐of‐the‐art results of the error rate for optical flow prediction on the Multi‐Vehicle Stereo Event Camera (MVSEC) dataset compared with the current SNN‐based approaches is demonstrated.
- Published
- 2023
- Full Text
- View/download PDF
3. Targeted RNA N6‐Methyladenosine Demethylation Controls Cell Fate Transition in Human Pluripotent Stem Cells
- Author
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Xuena Chen, Qingquan Zhao, Yu‐Li Zhao, Guo‐Shi Chai, Weisheng Cheng, Zhiju Zhao, Jia Wang, Guan‐Zheng Luo, and Nan Cao
- Subjects
ALKBH5 ,CRISPR ,differentiation ,m6A RNA modification ,pluripotent stem cells ,Science - Abstract
Abstract Deficiency of the N6‐methyladenosine (m6A) methyltransferase complex results in global reduction of m6A abundance and defective cell development in embryonic stem cells (ESCs). However, it's unclear whether regional m6A methylation affects cell fate decisions due to the inability to modulate individual m6A modification in ESCs with precise temporal control. Here, a targeted RNA m6A erasure (TRME) system is developed to achieve site‐specific demethylation of RNAs in human ESCs (hESCs). TRME, in which a stably transfected, doxycycline‐inducible dCas13a is fused to the catalytic domain of ALKBH5, can precisely and reversibly demethylate the targeted m6A site of mRNA and increase mRNA stability with limited off‐target effects. It is further demonstrated that temporal m6A erasure on a single site of SOX2 is sufficient to control the differentiation of hESCs. This study provides a versatile toolbox to reveal the function of individual m6A modification in hESCs, enabling cell fate control studies at the epitranscriptional level.
- Published
- 2021
- Full Text
- View/download PDF
4. Reprogramming of fibroblasts into expandable cardiovascular progenitor cells via small molecules in xeno-free conditions
- Author
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Jia Wang, Shanshan Gu, Fang Liu, Zihao Chen, He Xu, Zhun Liu, Weisheng Cheng, Linwei Wu, Tao Xu, Zhongyan Chen, Ding Chen, Xuena Chen, Fanzhu Zeng, Zhiju Zhao, Mingliang Zhang, and Nan Cao
- Subjects
Mice ,Stem Cells ,Biomedical Engineering ,Animals ,Medicine (miscellaneous) ,Cell Differentiation ,Heart ,Bioengineering ,Fibroblasts ,Cellular Reprogramming ,Computer Science Applications ,Biotechnology - Abstract
A major hurdle in cardiac cell therapy is the lack of a bona fide autologous stem-cell type that can be expanded long-term and has authentic cardiovascular differentiation potential. Here we report that a proliferative cell population with robust cardiovascular differentiation potential can be generated from mouse or human fibroblasts via a combination of six small molecules. These chemically induced cardiovascular progenitor cells (ciCPCs) self-renew long-term in fully chemically defined and xeno-free conditions, with faithful preservation of the CPC phenotype and of cardiovascular differentiation capacity in vitro and in vivo. Transplantation of ciCPCs into infarcted mouse hearts improved animal survival and cardiac function up to 13 weeks post-infarction. Mechanistically, activated fibroblasts revert to a plastic state permissive to cardiogenic signals, enabling their reprogramming into ciCPCs. Expanded autologous cardiovascular cells may find uses in drug discovery, disease modelling and cardiac cell therapy.
- Published
- 2022
5. Sign Language Gesture Recognition and Classification Based on Event Camera with Spiking Neural Networks
- Author
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Xuena Chen, Li Su, Jinxiu Zhao, Keni Qiu, Na Jiang, and Guang Zhai
- Subjects
Computer Networks and Communications ,Hardware and Architecture ,Control and Systems Engineering ,Signal Processing ,sign language recognition ,event camera ,Electrical and Electronic Engineering ,DVS-sign language ,intelligent system ,spiking neural network - Abstract
Sign language recognition has been utilized in human–machine interactions, improving the lives of people with speech impairments or who rely on nonverbal instructions. Thanks to its higher temporal resolution, less visual redundancy information and lower energy consumption, the use of an event camera with a new dynamic vision sensor (DVS) shows promise with regard to sign language recognition with robot perception and intelligent control. Although previous work has focused on event camera-based, simple gesture datasets, such as DVS128Gesture, event camera gesture datasets inspired by sign language are critical, which poses a great impediment to the development of event camera-based sign language recognition. An effective method to extract spatio-temporal features from event data is significantly desired. Firstly, the event-based sign language gesture datasets are proposed and the data have two sources: traditional sign language videos to event stream (DVS_Sign_v2e) and DAVIS346 (DVS_Sign). In the present dataset, data are divided into five classification, verbs, quantifiers, position, things and people, adapting to actual scenarios where robots provide instruction or assistance. Sign language classification is demonstrated in spike neuron networks with a spatio-temporal back-propagation training method, leading to the best recognition accuracy of 77%. This work paves the way for the combination of event camera-based sign language gesture recognition and robotic perception for the future intelligent systems.
- Published
- 2023
- Full Text
- View/download PDF
6. Targeted RNA N6‐Methyladenosine Demethylation Controls Cell Fate Transition in Human Pluripotent Stem Cells
- Author
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Jia Wang, Weisheng Cheng, Yu-Li Zhao, Qingquan Zhao, Nan Cao, Zhiju Zhao, Xuena Chen, Guan-Zheng Luo, and Guo-Shi Chai
- Subjects
General Chemical Engineering ,Science ,General Physics and Astronomy ,Medicine (miscellaneous) ,02 engineering and technology ,Cell fate determination ,010402 general chemistry ,01 natural sciences ,Biochemistry, Genetics and Molecular Biology (miscellaneous) ,SOX2 ,General Materials Science ,Induced pluripotent stem cell ,Chemistry ,Cell growth ,Methyltransferase complex ,General Engineering ,RNA ,differentiation ,021001 nanoscience & nanotechnology ,ALKBH5 ,Embryonic stem cell ,0104 chemical sciences ,Cell biology ,Cell Fate Control ,CRISPR ,embryonic structures ,m6A RNA modification ,biological phenomena, cell phenomena, and immunity ,pluripotent stem cells ,0210 nano-technology - Abstract
Deficiency of the N6 -methyladenosine (m6 A) methyltransferase complex results in global reduction of m6 A abundance and defective cell development in embryonic stem cells (ESCs). However, it's unclear whether regional m6 A methylation affects cell fate decisions due to the inability to modulate individual m6 A modification in ESCs with precise temporal control. Here, a targeted RNA m6 A erasure (TRME) system is developed to achieve site-specific demethylation of RNAs in human ESCs (hESCs). TRME, in which a stably transfected, doxycycline-inducible dCas13a is fused to the catalytic domain of ALKBH5, can precisely and reversibly demethylate the targeted m6 A site of mRNA and increase mRNA stability with limited off-target effects. It is further demonstrated that temporal m6 A erasure on a single site of SOX2 is sufficient to control the differentiation of hESCs. This study provides a versatile toolbox to reveal the function of individual m6 A modification in hESCs, enabling cell fate control studies at the epitranscriptional level.
- Published
- 2021
7. ERF72 interacts with ARF6 and BZR1 to regulate hypocotyl elongation in Arabidopsis
- Author
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Yingdian Wang, Xuena Chen, Lijuan Li, Shengcheng Han, Kun Liu, Yihao Li, Kai Liu, and Heping Zhao
- Subjects
0106 biological sciences ,0301 basic medicine ,Arabidopsis thaliana ,Light ,Transcription, Genetic ,Physiology ,Arabidopsis ,Plant Science ,ERF72 ,01 natural sciences ,Hypocotyl ,03 medical and health sciences ,chemistry.chemical_compound ,Plant Growth Regulators ,Transcription (biology) ,Auxin ,Gene Expression Regulation, Plant ,Brassinosteroid ,ARF6 ,Transcription factor ,chemistry.chemical_classification ,biology ,Chemistry ,Arabidopsis Proteins ,Sequence Analysis, RNA ,hypocotyl elongation ,fungi ,food and beverages ,Nuclear Proteins ,Darkness ,biology.organism_classification ,Plants, Genetically Modified ,Research Papers ,Cell biology ,photomorphogenesis ,DNA-Binding Proteins ,BZR1 ,030104 developmental biology ,RNA, Plant ,Gibberellin ,Photomorphogenesis ,Growth and Development ,010606 plant biology & botany ,Protein Binding ,Signal Transduction ,Subcellular Fractions ,Transcription Factors - Abstract
Hypocotyl cell elongation related to photomorphogenesis in Arabidopsis seedlings is regulated by a network involving ethylene, auxin, and brassinosteroid signalling that is mediated by interactions among ERF72, ARF6, and BZR1, forming a revised BZR-ARF-PIF/DELLA-ERF (BAP/DE) module., The phytohormones brassinosteroid (BR), auxin, and gibberellin (GA) regulate photomorphogenesis-related hypocotyl elongation in Arabidopsis via the co-operative interaction of BZR-ARF-PIF/DELLA (BAP/D) transcription factors/regulators. In addition, ethylene activates the PIF3 or ERF1 pathway through EIN3/EIL1 to balance hypocotyl elongation in Arabidopsis seedlings. However, the mechanism by which ethylene is co-ordinated with other phytohormones to produce light-regulated hypocotyl growth remains elusive. In this study, we found that hypocotyl cell elongation is regulated by a network involving ethylene, auxin, and BR signalling, which is mediated by interactions among ERF72, ARF6, and BZR1. ERF72 interacted directly with ARF6 and BZR1 in vitro and in vivo, and it antagonised regulation by ARF6 and BZR1 of the transcription of BEE3 and XTH7. In addition, light modulated the subcellular localisation of ERF72 and transcription of ERF72 through the EIN2-EIN3/EIL1 pathway, facilitating the function of ERF72 in photomorphogenesis. The expression of BEE3 and XTH7 was also regulated by the EIN2-EIN3/EIL1 pathway. Our findings indicate that a revised BZR-ARF-PIF/DELLA-ERF (BAP/DE) module integrates light and hormone signals to regulate hypocotyl elongation in Arabidopsis.
- Published
- 2018
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