The construction and characterization of the bi-directional promoter between pp38 gene and 1.8-kb mRNA transcripts of Marek's disease viruses

<p>Abstract</p> <p>Background</p> <p>Marek's disease virus (MDV) has a bi-directional promoter between pp38 gene and 1.8-kb mRNA transcripts. By sequencing for the promoters from 8 different strains (CVI988, 814, GA, JM, Md5, G2, RB1B and 648A), it is found, comparing with the other 7 MDV strains, CVI988 has a 5-bp (from -628 to -632) deletion in this region, which caused a Sp1 site destroyed. In order to analysis the activity of the promoter, the complete bi-directional promoters from GA and CVI988 were, respectively, cloned into pCAT-Basic vector in both directions for the recombinants pP_GA(pp38)-CAT, pP_GA(1.8 kb)-CAT, pP_CVI(pp38)-CAT and pP_CVI(1.8 kb)-CAT. The complete promoter of GA was divided into two single-direction promoters from the replication of MDV genomic DNA, and cloned into pCAT-Basic for pdP_GA(pp38)-CAT and pdP_GA(1.8 kb)-CAT as well. The above 6 recombinants were then transfected into chicken embryo fibroblasts (CEFs) infected with MDV, and the activity of chloramphenicol acetyltransferase (CAT) was measured from the lysed CEFs 48 h post transfection.</p> <p>Results</p> <p>The results showed the activity of the divided promoters was decreased on both directions. In 1.8-kb mRNA direction, it is nearly down to 2.4% (19/781) of the whole promoter, while it keeps 65% (34/52) activity in pp38 direction. The deletion of Sp1 site in CVI988 causes the 20% activity decreased, and has little influence in pp38 direction.</p> <p>Conclusion</p> <p>The present study confirmed their result, and the promoter for the 1.8-kb mRNA transcripts is a much stronger promoter than that in the orientation for pp38.</p

Deletion of 1.8-kb mRNA of Marek's disease virus decreases its replication ability but not oncogenicity

<p>Abstract</p> <p>Background</p> <p>The 1.8-kb mRNA was reported as one of the oncogenesis-related genes of Marek's disease virus (MDV). In this study, the bacterial artificial chromosome (BAC) clone of a MDV field strain GX0101 was used as the platform to generate mutant MDV to examine the functional roles of 1.8-kb mRNA.</p> <p>Results</p> <p>Based on the BAC clone of GX0101, the 1.8-kb mRNA deletion mutant GX0101Δ(A+C) was constructed. The present experiments indicated that GX0101Δ(A+C) retained a low level of oncogenicity, and it showed a decreased replication capacity in vitro and in vivo when compared with its parent virus, GX0101. Further studies in vitro demonstrated that deletion of 1.8-kb mRNA significantly decreased the transcriptional activity of the bi-directional promoter between 1.8-kb mRNA and pp38 genes of MDV.</p> <p>Conclusion</p> <p>These results suggested that the 1.8-kb mRNA did not directly influence the oncogenesis but related to the replication ability of MDV.</p

Heterogeneous federated bidirectional knowledge distillation transfer semi-supervised modulation recognition

The large-scale deployment and rapid development of the new generation mobile communication system underpin the widespread application of a massive and diverse range of Internet of things (IoT) devices.However, the distributed application of IoT devices results to significant disparities in private data and substantial heterogeneity in local processing models, which severely limits the aggregation capability of global intelligent model.Therefore, to tackle the challenges of data heterogeneity, model heterogeneity, and insufficient labeling faced by intelligent modulation recognition in cognitive IoT, an algorithm was proposed for heterogeneous federated bidirectional semi-supervised modulation recognition, which incorporated bidirectional knowledge distillation.In the proposed algorithm, a public pseudo dataset was generated by variational autoencoder in the cloud for supporting uplink global knowledge distillation, and adaptively sharing to the local devices for downlink heterogeneous knowledge distillation, while integrating a semi-supervised algorithm within the distillation process.The simulation results indicate that the proposed algorithm outperforms current federated learning algorithms in terms of effectiveness and applicability in the field of communication signal processing

Global South shows higher urban flood exposures than the Global North under current and future scenarios

Urbanization has intensified in recent decades, raising concerns about increasing flood exposure in cities. Here, we assess urban flood exposure in terms of built-up area, population, and economic activity located within zones affected by 1-in-100-year river flood events. We use global historical data from 2000 to 2020 and future projections from 2030 to 2100 under the Shared Socioeconomic Pathways. From 2000 to 2020, global urban flood exposure increased substantially, with the most severe impacts in East Asia and the fastest growth in Africa. Future exposure continues to rise, especially under high-risk development scenarios. From 2030 to 2100, flood-exposed urban area, population, and economy in Global South are more than twice, nearly five times, and over twice those in Global North, respectively. Inequality in exposure is greater within developing regions than developed ones. These disparities are projected to widen, highlighting the urgent need for targeted, region-specific strategies to reduce flood risks