Port and terminal efficiency are of utmost importance to the container shipping industry due to their significance in enhancing the competitive advantage of ports within a region. Consequently, there have always been ...Port and terminal efficiency are of utmost importance to the container shipping industry due to their significance in enhancing the competitive advantage of ports within a region. Consequently, there have always been notable variations of studies around it. This paper analyzes the impact of privatization on terminal efficiency using the Port of Tema as a Case Study. The main objective of this paper is to analyze the efficiency trends of the public and private terminals in the port over the years. To achieve this objective, DEA-CCR methodology was employed to calculate the annual technical efficiency trends of the private and public terminals using four input variables and three output variables. The main results of the paper indicated that the public and private terminals were efficient for multiple years. However, the efficiency scores over the years demonstrated inconsistency, exhibiting notable fluctuations. The findings of this study will aid policymakers across the region on policies relating to the efficiency and ownership structure of ports and terminals.展开更多
The primary function of terminators is to terminate transcription in gene expression.Although some studies have suggested that terminators also contribute positively to upstream gene expression,the extent and underlyi...The primary function of terminators is to terminate transcription in gene expression.Although some studies have suggested that terminators also contribute positively to upstream gene expression,the extent and underlying mechanism of this effect remain largely unexplored.Here,the correlation between terminating strength and upstream mRNA stability was investigated by constructing a terminator mutation library through randomizing 5 nucleotides,assisted by FlowSeq technology,terminator variants were categorized based on the downstream fluorescence intensity,followed by high-throughput sequencing.To examine the impact of terminators on mRNA stability,the abundance of downstream gene transcripts for each terminator variant was quantified through cDNA sequencing.The results revealed that the transcript abundance controlled by strong terminators was,on average 2.2 times greater than those controlled by weak terminators on average.Moreover,several distinct features could be ascribed to high relative abundance of upstream gene transcript,including a high GC content at the base region of hairpin,and a high AT content in downstream of the U-tract.Additionally,these terminators showed a free energy between28 and22 kcal/mol,and a stem length of 14 nt.Finally,these features ascribed the upstream beneficial terminator were validated across various expression systems.By incorporating the optimal terminator downstream of RSF,GSH and HIS in three different strains,the fermentation productions-NMN SAM and VD13 exhibited a remarkable enhancement of 30%-70%.The findings presented here uncov-ered the terminator characteristics contributed to the upstream mRNA stability,providing guiding principles for gene circuit design.展开更多
文摘Port and terminal efficiency are of utmost importance to the container shipping industry due to their significance in enhancing the competitive advantage of ports within a region. Consequently, there have always been notable variations of studies around it. This paper analyzes the impact of privatization on terminal efficiency using the Port of Tema as a Case Study. The main objective of this paper is to analyze the efficiency trends of the public and private terminals in the port over the years. To achieve this objective, DEA-CCR methodology was employed to calculate the annual technical efficiency trends of the private and public terminals using four input variables and three output variables. The main results of the paper indicated that the public and private terminals were efficient for multiple years. However, the efficiency scores over the years demonstrated inconsistency, exhibiting notable fluctuations. The findings of this study will aid policymakers across the region on policies relating to the efficiency and ownership structure of ports and terminals.
基金supported by National Natural Science Foundation of China[32171421].
文摘The primary function of terminators is to terminate transcription in gene expression.Although some studies have suggested that terminators also contribute positively to upstream gene expression,the extent and underlying mechanism of this effect remain largely unexplored.Here,the correlation between terminating strength and upstream mRNA stability was investigated by constructing a terminator mutation library through randomizing 5 nucleotides,assisted by FlowSeq technology,terminator variants were categorized based on the downstream fluorescence intensity,followed by high-throughput sequencing.To examine the impact of terminators on mRNA stability,the abundance of downstream gene transcripts for each terminator variant was quantified through cDNA sequencing.The results revealed that the transcript abundance controlled by strong terminators was,on average 2.2 times greater than those controlled by weak terminators on average.Moreover,several distinct features could be ascribed to high relative abundance of upstream gene transcript,including a high GC content at the base region of hairpin,and a high AT content in downstream of the U-tract.Additionally,these terminators showed a free energy between28 and22 kcal/mol,and a stem length of 14 nt.Finally,these features ascribed the upstream beneficial terminator were validated across various expression systems.By incorporating the optimal terminator downstream of RSF,GSH and HIS in three different strains,the fermentation productions-NMN SAM and VD13 exhibited a remarkable enhancement of 30%-70%.The findings presented here uncov-ered the terminator characteristics contributed to the upstream mRNA stability,providing guiding principles for gene circuit design.
