RF-Net: An End-to-End Image Matching Network based on Receptive Field

This paper proposes a new end-to-end trainable matching network based on receptive field, RF-Net, to compute sparse correspondence between images. Building end-to-end trainable matching framework is desirable and challenging. The very recent approach, LF-Net, successfully embeds the entire feature extraction pipeline into a jointly trainable pipeline, and produces the state-of-the-art matching results. This paper introduces two modifications to the structure of LF-Net. First, we propose to construct receptive feature maps, which lead to more effective keypoint detection. Second, we introduce a general loss function term, neighbor mask, to facilitate training patch selection. This results in improved stability in descriptor training. We trained RF-Net on the open dataset HPatches, and compared it with other methods on multiple benchmark datasets. Experiments show that RF-Net outperforms existing state-of-the-art methods.Comment: 9 pages, 6 figure

Deep regression for LiDAR-based localization in dense urban areas

LiDAR-based localization in a city-scale map is a fundamental question in autonomous driving research. As a reasonable localization scheme, the localization can be performed by global retrieval (that suggests potential candidates from the database) followed by geometric registration (that obtains an accurate relative pose). In this work, we develop a novel end-to-end, deep multi-task network that simultaneously performs global retrieval and geometric registration for LiDAR-based localization. Both retrieval and registration are formulated and solved as regression problems, and they can be deployed independently during inference time. We also design two mechanisms to enhance our multi-task regression network\u27s performance: residual connections for point clouds and a new loss function with learnable parameters. To alleviate the common phenomenon of vanishing gradients in neural networks, we employ residual connections to support constructing a deeper network effectively. At the same time, to solve the problem of huge differences in scale and units between different tasks, we propose a loss function that can automatically balance multi-tasks. Experiments on two public benchmarks validate the state-of-the-art performance of our algorithm in large-scale LiDAR-based localization

Intranasal Immunization with a Recombinant Avian Paramyxovirus Serotypes 2 Vector-Based Vaccine Induces Protection against H9N2 Avian Influenza in Chicken

Commercial inactivated vaccines against H9N2 avian influenza (AI) have been developed in China since 1990s and show excellent immunogenicity with strong HI antibodies. However, currently approved vaccines cannot meet the clinical demand for a live-vectored vaccine. Newcastle disease virus (NDV) vectored vaccines have shown effective protection in chickens against H9N2 virus. However, preexisting NDV antibodies may affect protective efficacy of the vaccine in the field. Here, we explored avian paramyxovirus serotype 2 (APMV-2) as a vector for developing an H9N2 vaccine via intranasal delivery. APMV-2 belongs to the same genus as NDV, distantly related to NDV in the phylogenetic tree, based on the sequences of Fusion (F) and hemagglutinin-neuraminidase (HN) gene, and has low cross-reactivity with anti-NDV antisera. We incorporated hemagglutinin (HA) of H9N2 into the junction of P and M gene in the APMV-2 genome by being flanked with the gene start, gene end, and UTR of each gene of APMV-2-T4 to generate seven recombinant APMV-2 viruses rAPMV-2/HAs, rAPMV-2-NPUTR-HA, rAPMV-2-PUTR-HA, rAPMV-2-FUTR-HA, rAPMV-2-HNUTR-HA, rAPMV-2-LUTR-HA, and rAPMV-2-MUTR-HA, expressing HA. The rAPMV-2/HAs displayed similar pathogenicity compared with the parental APMV-2-T4 virus and expressed HA protein in infected CEF cells. The NP-UTR facilitated the expression and secretion of HA protein in cells infected with rAPMV-2-NPUTR-HA. Animal studies demonstrated that immunization with rAPMV-2-NPUTR-HA elicited effective H9N2-specific antibody (6.14 ± 1.2 log2) responses and conferred complete immune protection to prevent viral shedding in the oropharyngeal and cloacal swabs from chickens challenged with H9N2 virus. This study suggests that our recombinant APMV-2 virus is safe and immunogenic and can be a useful tool in the combat of H9N2 outbreaks in chicken

HNP inhibits the eIF4A1-dependent translation.

(A) A lentiviral packaging system was used to express NDV-NP protein in HeLa cells, and NP expression was detected by Western blotting. (B) The statistical plot of the number of differentially expressed genes (DEGs) in each group (fc>1, p1, pp<0.0001.</p

HNP protein physically interacts with eIF4A1 with 366-489aa.

(A) Co-immunoprecipitation (Co-IP) of NP protein with endogenous eIF4A1 during NDV infection. HeLa cells were infected with rHerts/33, rI4, or mock-infected and subjected to IP using anti-NP protein or anti-eIF4A1 antibodies. Immunoblotting was performed using the indicated antibodies. (B) HeLa cells were transfected with His-tagged HNP or INP and HA-tagged eIF4A1. After 36 hours, HNP’s interaction with eIF4A1 was confirmed through Co-IP using both anti-NP and anti-HA antibodies. (C) GST pull-down assay. Glutathione beads were conjugated with GST or GST-NP fusion protein and incubated with lysate from cells overexpressing eIF4A1. Eluted proteins were subjected to Western Blot, and eIF4A1 presence was detected using anti-HA antibody. GST, GST-HNP, and GST-INP protein expression was confirmed with anti-GST antibody. (D) Redistribution and colocalization of eIF4A1 with HNP protein. HeLa cells were transfected with His-tagged HNP or INP and HA-tagged eIF4A1, fixed at 24 hpi, stained with anti-eIF4A1 and anti-NP antibodies, and visualized using confocal microscopy. (E) Direct interaction between eIF4A1 and HNP confirmed by Bifc assay. Venus luminescence was observed after separate or co-transfection of VC155-eIF4A1, VN173-HNP, and VN173-INP. (F) The C-terminal region 366-489aa of NP is sufficient for heterologous protein association with eIF4A1. Multiple C-terminal and N-terminal truncations of His-tagged NP were expressed in HeLa cells and subjected to IP experiments using anti-eIF4A1 antibody, followed by analysis with specific antibody immunoblotting.</p

450th-L-NP mediates a higher translation efficiency of GFP mRNA from the minigenome.

(A) Cells were collected at 24h after transfection of minigenome or the control plasmid, and half of them were lysed to isolate ribosomes. Top: Total cytoplasmic ribosomes were separated by sucrose density gradient centrifugation, and the absorbance of each fraction was measured at 254nm. Cycloheximide was present in each sample. Lower panel: Protein in half of each fraction’s volume was subjected to TCA precipitation and subsequently utilized for immunoblotting with anti-His and anti-rpS6 antibodies. (B) The remaining half of the cells were extracted for total RNA to detect the mRNA of GFP by quantitative RT-PCR. The results represent the mean ± SD of a representative quantitative RT-PCR experiment conducted in triplicate. (C) Samples from the remaining half of each fraction after ribosome isolation were extracted for RNA and assayed for the distribution of mRNA of GFP in complex with ribosomes by quantitative RT-PCR. Results are the mean ± SD of a representative quantitative RT-PCR experiment performed in duplicate three times. Significance was analyzed by two-way ANOVA. (** means pp<0.001). (D) Schematic representation of NP protein deletion mutants. Boxes indicate the protein product of each truncated NP gene, with amino acid positions indicated above the boxes. Straight lines indicate the region of deletion. (E) Residues 122–366 and 366–489 of NP are sufficient for its localization to the ribosome. Multiple c- and n-terminal truncated NPs were expressed in HeLa cells. Cell extracts from transfected cells were subjected to 10–50% sucrose density gradient ultracentrifugation. RNase (100U/mL) was added to the cell lysate to eliminate the impact of varying RNA levels on polyribosome enrichment. Protein in each fraction was subjected to TCA precipitation and subsequently utilized for immunoblotting with anti-His and anti-rpS6 antibodies.</p

Construction strategy and primers for generating minigenome system-related plasmids.

Construction strategy and primers for generating minigenome system-related plasmids.</p