In Beyond the Fifth Generation(B5G)heterogeneous edge networks,numerous users are multiplexed on a channel or served on the same frequency resource block,in which case the transmitter applies coding and the receiver u...In Beyond the Fifth Generation(B5G)heterogeneous edge networks,numerous users are multiplexed on a channel or served on the same frequency resource block,in which case the transmitter applies coding and the receiver uses interference cancellation.Unfortunately,uncoordinated radio resource allocation can reduce system throughput and lead to user inequity,for this reason,in this paper,channel allocation and power allocation problems are formulated to maximize the system sum rate and minimum user achievable rate.Since the construction model is non-convex and the response variables are high-dimensional,a distributed Deep Reinforcement Learning(DRL)framework called distributed Proximal Policy Optimization(PPO)is proposed to allocate or assign resources.Specifically,several simulated agents are trained in a heterogeneous environment to find robust behaviors that perform well in channel assignment and power allocation.Moreover,agents in the collection stage slow down,which hinders the learning of other agents.Therefore,a preemption strategy is further proposed in this paper to optimize the distributed PPO,form DP-PPO and successfully mitigate the straggler problem.The experimental results show that our mechanism named DP-PPO improves the performance over other DRL methods.展开更多
The polyphenoloxidase（PPO） is the key enzyme considered to be responsible for mushroom browning.By using homology cloning and rapid amplification of cDNA ends（RACE）,two new PPO genes and the corresponding cDNA wer...The polyphenoloxidase（PPO） is the key enzyme considered to be responsible for mushroom browning.By using homology cloning and rapid amplification of cDNA ends（RACE）,two new PPO genes and the corresponding cDNA were identified from the fruit bodies of Agaricus bisporus（AbPPO3 and AbPPO4,GenBank accession nos.GU936494 and GU936493,respectively）.The genomic DNA sequences of AbPPO3 and AbPPO4 are 2 080 and 2 189 bp in length,respectively,encoding putative polypeptides of approximately 66 and 68 kDa.The deduced amino acid sequences show characteristic features of two copper-binding domains conserved in the type III copper proteins including fungal polyphenol oxidases.Sequence comparisons indicate that AbPPO3 and AbPPO4 present 55.3% similarity to each other（48% identity）.We also obtained more than 1.5-kb long sequences upstream of the start codon of the AbPPO3 and AbPPO4 and recognized them as their respective putative promoters.Analyses of the two PPO promoter regions show that they contain abundant cis-acting elements which are probably responsible for anaerobic induction,light,wound,stress,and auxin response.Semi-quantitative RT-PCR results indicate that AbPPO3 and AbPPO4 were highly expressed in the mature fruit bodies and up-regulated after 2-d storage of mushroom.These results suggest that AbPPO3 and AbPPO4 may play roles in A.bisporus browning and pigmentation during development and postharvest storage and the elements in promoters may act as regulatory elements for the inducible expression of AbPPO3 and AbPPO4.The successful cloning and expression analysis of AbPPO3 and AbPPO4 warrant a further investigation on the structure and function of A.bisporus PPO which points to the possible targets for genetic manipulation.展开更多
In this study, the activities of phenylalanine ammonia lyase （PAL）, polyphenoloxidase （PPO）, and peroxidase （POD） were assayed in cucumber seedlings （Cucumis sativus L.） at 0, 6, 12, 24, 48, 72, and 96 h after...In this study, the activities of phenylalanine ammonia lyase （PAL）, polyphenoloxidase （PPO）, and peroxidase （POD） were assayed in cucumber seedlings （Cucumis sativus L.） at 0, 6, 12, 24, 48, 72, and 96 h after they were infested by Bemisia tabaci （Gennadius） using spectrophotometric analysis. The results indicated that herbivore infestation increased the activities of PAL, PPO, and POD. The enzymes showed different activity levels at different times after the infestation. The PAL activity reached the first high peak by 23.1% at 6 h and the highest peak by 29.1% at 48 h compared to the control. The PPO activity reached the first high peak by 22.7% at 6 h and the highest peak by 52.6% at 24 h, and the POD activity reached the highest peak by 213.2% at 6 h and another higher peak value by 135.2% at 96 h. The results suggest that the enhanced activities of the enzymes may contribute to bioprotection of cucumber plants against B. tabaci infestation.展开更多
基金supported by the Key Research and Development Program of China(No.2022YFC3005401)Key Research and Development Program of China,Yunnan Province(No.202203AA080009,202202AF080003)Postgraduate Research&Practice Innovation Program of Jiangsu Province(No.KYCX21_0482).
文摘In Beyond the Fifth Generation(B5G)heterogeneous edge networks,numerous users are multiplexed on a channel or served on the same frequency resource block,in which case the transmitter applies coding and the receiver uses interference cancellation.Unfortunately,uncoordinated radio resource allocation can reduce system throughput and lead to user inequity,for this reason,in this paper,channel allocation and power allocation problems are formulated to maximize the system sum rate and minimum user achievable rate.Since the construction model is non-convex and the response variables are high-dimensional,a distributed Deep Reinforcement Learning(DRL)framework called distributed Proximal Policy Optimization(PPO)is proposed to allocate or assign resources.Specifically,several simulated agents are trained in a heterogeneous environment to find robust behaviors that perform well in channel assignment and power allocation.Moreover,agents in the collection stage slow down,which hinders the learning of other agents.Therefore,a preemption strategy is further proposed in this paper to optimize the distributed PPO,form DP-PPO and successfully mitigate the straggler problem.The experimental results show that our mechanism named DP-PPO improves the performance over other DRL methods.
基金supported by Zhejiang Provincial Natural Science Foundation of China (Y306633 and Y3100579)Zhejiang Provincial Edible Fungi Industrial Innovation Team Project of China
文摘The polyphenoloxidase（PPO） is the key enzyme considered to be responsible for mushroom browning.By using homology cloning and rapid amplification of cDNA ends（RACE）,two new PPO genes and the corresponding cDNA were identified from the fruit bodies of Agaricus bisporus（AbPPO3 and AbPPO4,GenBank accession nos.GU936494 and GU936493,respectively）.The genomic DNA sequences of AbPPO3 and AbPPO4 are 2 080 and 2 189 bp in length,respectively,encoding putative polypeptides of approximately 66 and 68 kDa.The deduced amino acid sequences show characteristic features of two copper-binding domains conserved in the type III copper proteins including fungal polyphenol oxidases.Sequence comparisons indicate that AbPPO3 and AbPPO4 present 55.3% similarity to each other（48% identity）.We also obtained more than 1.5-kb long sequences upstream of the start codon of the AbPPO3 and AbPPO4 and recognized them as their respective putative promoters.Analyses of the two PPO promoter regions show that they contain abundant cis-acting elements which are probably responsible for anaerobic induction,light,wound,stress,and auxin response.Semi-quantitative RT-PCR results indicate that AbPPO3 and AbPPO4 were highly expressed in the mature fruit bodies and up-regulated after 2-d storage of mushroom.These results suggest that AbPPO3 and AbPPO4 may play roles in A.bisporus browning and pigmentation during development and postharvest storage and the elements in promoters may act as regulatory elements for the inducible expression of AbPPO3 and AbPPO4.The successful cloning and expression analysis of AbPPO3 and AbPPO4 warrant a further investigation on the structure and function of A.bisporus PPO which points to the possible targets for genetic manipulation.
文摘In this study, the activities of phenylalanine ammonia lyase （PAL）, polyphenoloxidase （PPO）, and peroxidase （POD） were assayed in cucumber seedlings （Cucumis sativus L.） at 0, 6, 12, 24, 48, 72, and 96 h after they were infested by Bemisia tabaci （Gennadius） using spectrophotometric analysis. The results indicated that herbivore infestation increased the activities of PAL, PPO, and POD. The enzymes showed different activity levels at different times after the infestation. The PAL activity reached the first high peak by 23.1% at 6 h and the highest peak by 29.1% at 48 h compared to the control. The PPO activity reached the first high peak by 22.7% at 6 h and the highest peak by 52.6% at 24 h, and the POD activity reached the highest peak by 213.2% at 6 h and another higher peak value by 135.2% at 96 h. The results suggest that the enhanced activities of the enzymes may contribute to bioprotection of cucumber plants against B. tabaci infestation.
