Transformers in computational visual media:A survey

Transformers,the dominant architecture for natural language processing,have also recently attracted much attention from computational visual media researchers due to their capacity for long-range representation and high performance.Transformers are sequence-to-sequence models,which use a selfattention mechanism rather than the RNN sequential structure.Thus,such models can be trained in parallel and can represent global information.This study comprehensively surveys recent visual transformer works.We categorize them according to task scenario:backbone design,high-level vision,low-level vision and generation,and multimodal learning.Their key ideas are also analyzed.Differing from previous surveys,we mainly focus on visual transformer methods in low-level vision and generation.The latest works on backbone design are also reviewed in detail.For ease of understanding,we precisely describe the main contributions of the latest works in the form of tables.As well as giving quantitative comparisons,we also present image results for low-level vision and generation tasks.Computational costs and source code links for various important works are also given in this survey to assist further development.

Positive feedback between retinoic acid and 2-phospho-L-ascorbic acid trisodium salt during somatic cell reprogramming

Retinoic acid(RA)and 2-phospho-L-ascorbic acid trisodium salt(AscPNa)promote the reprogramming of mouse embryonic fibroblasts to induced pluripotent stem cells.In the current studies,the lower abilities of RA and AscPNa to promote reprogramming in the presence of each other suggested that they may share downstream pathways at least partially.The hypothesis was further supported by the RNA-seq analysis which demonstrated a high-level overlap between RA-activated and AscPNa activated genes during reprogramming.In addition,RA upregulated Glut1/3,facilitated the membrane transportation of dehydroascorbic acid,the oxidized form of L-ascorbic acid,and subsequently maintained intracellular L-ascorbic acid at higher level and for longer time.On the other hand,AscPNa facilitated the mesenchymal-epithelial transition during reprogramming,downregulated key mesenchymal transcriptional factors like Zeb1 and Twist1,subsequently suppressed the expression of Cyp26a1/b1 which mediates the metabolism of RA,and sustained the intracellular level of RA.Furthermore,the different abilities of RA and AscPNa to induce mesenchymal-epithelial transition,pluripotency,and neuronal differentiation explain their complex contribution to reprogramming when used individually or in combination.Therefore,the current studies identified a positive feedback between RA and AscPNa,or possibility between vitamin A and C,and further explored their contributions to reprogramming.