Spatial-Temporal Pyramid Graph Reasoning for Action Recognition.

Spatial-temporal relation reasoning is a significant yet challenging problem for video action recognition. Previous works typically apply local operations like 2D or 3D CNNs to conduct space-time interactions in video sequences, or simply capture space-time long-range relations of a single fixed scale. However, this is inadequate for obtaining a comprehensive action representation. Besides, most models treat all input frames equally for the final classification, without selecting key frames and motion-sensitive regions. This introduces irrelevant video content and hurts the performance of models. In this paper, we propose a generic Spatial-Temporal Pyramid Graph Network (STPG-Net) to adaptively capture long-range spatial-temporal relations in video sequences at multiple scales. Specifically, we design a temporal attention (TA) module and a spatial-temporal attention (STA) module to learn the contribution of each frame and each space-time region to an action at a feature level, respectively. We then apply the selected key information to build spatial-temporal pyramid graphs for long-range relation reasoning and more comprehensive action representation learning. STPG-Net can be flexibly integrated into 2D and 3D backbone networks in a plug-and-play manner. Extensive experiments show that it brings consistent improvements over many challenging baselines on several standard action recognition benchmarks (i.e., Something-Something V1 & V2, and FineGym), demonstrating the effectiveness of our approach.

Evaluation of immunoprotective effects of recombinant proteins and DNA vaccines derived from Eimeria tenella surface antigen 6 and 15 in vivo.

Coccidiosis is an intestinal parasitic disease that causes huge economic losses to the poultry industry globally. Eimeria tenella belonging to protozoon is the causative agent of cecal coccidiosis in chicken, and it causes enormous damage to poultry industry. The surface antigens (SAGs) of apicomplexan parasites have functions of attachment and invasion in host-parasite interaction. As a result of parasitic invasion, host immune response is triggered. However, the immunogenicity and potency of E. tenella surface antigen 6 and 15 (EtSAG 6 and 15), as vaccinal candidate antigen, remain largely unknown. Therefore, gene fragments of E. tenella EtSAG 6 and 15 were amplified and transformed to pET28a prokaryotic vector for recombinant protein expression. The pEGFP-N1 eukaryotic vectors with EtSAG 6 and 15 amplification fragments (pEGFP-N1-EtSAG 5 and 16) were transformed into 293 T cell line. The results of reverse transcription-polymerase chain reaction (RT-PCR) and western blot analysis revealed successful expressions of EtSAG 6 and 15 in Escherichia coli and 293 T cells. Subsequently, animal experiments of 49 cobb broilers were performed to evaluate immunoprotection of recombinant proteins and DNA vaccines derived from E. tenella EtSAG 5 and 16 with an immunizing dose of 100 µg, respectively. Chickens vaccinated with rEtSAG 6 protein, rEtSAG 15 protein, pEGFP-N1-EtSAG 6 plasmid, or pEGFP-N1-EtSAG 15 plasmid showed no significant increase in IFN-γor interleukin-4 (IL-4) level compared with control groups. Chickens vaccinated with protein rEtSAG 6, protein rEtSAG 15, pEGFP-N1-EtSAG 6 plasmid, or pEGFP-N1-EtSAG 15 exhibited higher weight gains, lower oocyst output, and lower mean lesion scores, compared with infection control group. Among the four immunized groups, plasmid EGFP-N1-EtSAG 6 (100 µg) group exhibited the highest anticoccidial index (ACI) value (150.20). Overall, plasmids EGFP-N1-EtSAG 6 and 15, as DNA vaccines, provided a more effective immunoprotection for chickens against E. tenella than protein rEtSAG 6 and protein rEtSAG 15 as subunit vaccines. EtSAG 6 and 15 are promising candidate antigen genes for developing coccidiosis vaccine.

Foliar Application of Silicon Enhances Resistance Against Phytophthora infestans Through the ET/JA- and NPR1- Dependent Signaling Pathways in Potato.

Late blight (LB), caused by the oomycete pathogen Phytophthora infestans, is a devastating disease of potato that is necessary to control by regularly treatment with fungicides. Silicon (Si) has been used to enhance plant resistance against a broad range of bacterial and fungal pathogens; however, the enhanced LB resistance and the molecular mechanisms involving the plant hormone pathways remain unclear. In this study, Si treatment of potato plants was found to enhance LB resistance in both detached leaves and living plants accompanied by induction of reactive oxygen species (ROS) production and pathogenesis-related genes expression. Regarding the hormone pathways involved in Si-mediated LB resistance, we found a rapidly increased content of ethylene (ET) 15 min after spraying with Si. Increased jasmonic acid (JA) and JA-Ile and decreased salicylic acid (SA) were identified in plants at 1 day after spraying with Si and an additional 1 day after P. infestans EC1 infection. Furthermore, pretreatment with Me-JA enhanced resistance to EC1, while pretreatment with DIECA, an inhibitor of JA synthesis, enhanced the susceptibility and attenuated the Si-mediated resistance to LB. Consistent with these hormonal alterations, Si-mediated LB resistance was significantly attenuated in StETR1-, StEIN2-, StAOS-, StOPR3-, StNPR1-, and StHSP90-repressed plants but not in StCOI1- and StSID2-repressed plants using virus-induced gene silencing (VIGS). The Si-mediated accumulation of JA/JA-Ile was significantly attenuated in StETR1-, StEIN2-, StOPR3- and StHSP90-VIGS plants but not in StCOI1-, StSID2- and StNPR1-VIGS plants. Overall, we reveal that Si can be used as a putative alternative to fungicides to control LB, and conclude that Si-mediated LB resistance is dependent on the ET/JA-signaling pathways in a StHSP90- and StNPR1-dependent manner.

Prevalence of Eimeria parasites in the Hubei and Henan provinces of China.

Coccidiosis is an intestinal parasitic disease that causes huge economic losses in the poultry industry globally. Henan and Hubei, as important poultry production provinces in China, have great pressure for the prevention and control of chicken coccidiosis. In order to obtain information on the local prevalence of Eimeria species, we used an internal transcribed spacer 1 (ITS1) sequence of ribosomal DNA to identify the species from 318 fresh fecal samples. The fecal samples and the data relating to farm information were collected from 137 farms in Hubei and Henan provinces. As shown by genus-specific PCR results, the positivity rate of Eimeria was 97.17% (309/318), and the most common species were Eimeria mitis (66.67%), E. tenella (46.86%), and E. necatrix (41.51%). Then, we analyzed the correlation between the background information of each sample and the PCR identification results, which showed that indigenous farms in Henan province were at the greatest risk of harboring highly pathogenic Eimeria species and a larger proportion of such farms were positive for E. necatrix, the most pathogenic species. The results of this study showed that chicken coccidia was widespread, which provides important insights into the control of chicken coccidiosis in this region.