CO3D MISSION DIGITAL SURFACE MODEL PRODUCTION PIPELINE

Abstract. Earth Observation (EO) remote sensing missions are producing an increasing volume of data due to higher spatial and spectral resolutions, and higher frequency of acquisitions. Thus, in order to prepare the future of image processing pipelines, CNES has carried out Research & Development studies related to the use of Big Data and Cloud technologies for image processing chains made. Since mid-2019, CNES in partnership with Airbus Defense & Space, has started a new High Resolution Optical EO mission dedicated to very high resolution 3D observation called CO3D (“Constellation Optique 3D”). To achieve those objectives, a new image processing pipeline prototype is being developed taking in consideration the lessons learned from the previous studies. The paper will introduce this new image processing pipeline, the processing paradigms used to take advantage of big data technologies and the results of production benchmarks at a large scale. The on-going works to optimize the processing pipeline and Cloud cluster will be also discussed. Document type: Articl

A NEW SATELLITE IMAGERY STEREO PIPELINE DESIGNED FOR SCALABILITY, ROBUSTNESS AND PERFORMANCE

Abstract. This paper presents a new Multiview Stereo Pipeline (MVS), called CARS, dedicated to satellite imagery. This pipeline is intended for massive Digital Surface Model (DSM) production and has therefore been designed to maximize scalability robustness and performance. Those two properties have driven the design of the workflow as well as the choice of algorithms and parameter trends, making our pipeline unique with respect to existing solutions in literature. This paper intends to serve as a reference paper for the pipeline implementation, and therefore provides a detailed description of algorithms and workflow. It also demonstrates the pipeline robustness and stability in several use cases, and compares its accuracy with the state-of-the-art pipelines on a reference dataset. Document type: Articl

Functional and structural studies of the vaccinia virus virulence factor N1 reveal a Bcl-2-like anti-apoptotic protein

Vaccinia virus (VACV) encodes many immunomodulatory proteins, including inhibitors of apoptosis and modulators of innate immune signalling. VACV protein N1 is an intracellular homodimer that contributes to virus virulence and was reported to inhibit nuclear factor (NF)-κB signalling. However, analysis of NF-κB signalling in cells infected with recombinant viruses with or without the N1L gene showed no difference in NF-κB-dependent gene expression. Given that N1 promotes virus virulence, other possible functions of N1 were investigated and this revealed that N1 is an inhibitor of apoptosis in cells transfected with the N1L gene and in the context of VACV infection. In support of this finding virally expressed N1 co-precipitated with endogenous pro-apoptotic Bcl-2 proteins Bid, Bad and Bax as well as with Bad and Bax expressed by transfection. In addition, the crystal structure of N1 was solved to 2.9 Å resolution (0.29 nm). Remarkably, although N1 shows no sequence similarity to cellular proteins, its three-dimensional structure closely resembles Bcl-xL and other members of the Bcl-2 protein family. The structure also reveals that N1 has a constitutively open surface groove similar to the grooves of other anti-apoptotic Bcl-2 proteins, which bind the BH3 motifs of pro-apoptotic Bcl-2 family members. Molecular modelling of BH3 peptides into the N1 surface groove, together with analysis of their physico-chemical properties, suggests a mechanism for the specificity of peptide recognition. This study illustrates the importance of the evolutionary conservation of structure, rather than sequence, in protein function and reveals a novel anti-apoptotic protein from orthopoxviruses

Fast Pattern Spectra using Tree Representation of the Image for Patch Retrieval

International audienceWe extend the notion of content based image retrieval to patch retrieval where the goal is to find the similar patches to a query patch in a large image. Naive searching for similar patches by sequentially computing and comparing descriptors of sliding windows takes a lot of time in a large image. We propose a novel method to compute descriptors for all sliding windows independent from number of patches. We rely on tree representation of the image and exploit the histogram nature of pattern spectra to compute all the required descriptors in parallel. Computation time of the proposed method depends only on the number of tree nodes and is free from query selection. Experimental results show the effectiveness of the proposed method to reduce the computation time and its potential for object detection in large images

Does the Aortic Annulus Dilate After Aortic Root Remodeling?

Background The 2 main techniques of valve-sparing aortic root replacement (VSRR) are remodeling and reimplantation. There is concern that the aortic annulus, which is not stabilized in remodeling technique, may dilate over time and cause aortic regurgitation. Our aim was to assess whether the aortic annulus dilates after VSRR with remodeling technique without aortic annuloplasty. Methods Data on patients undergoing elective or urgent VSRR remodeling technique between 2005 and 2018 were collected. Patients undergoing arch and emergency surgery for acute type A aortic dissection were excluded. Preoperative aortic annulus diameter was measured by transthoracic echocardiography, and this was compared with the annulus diameter measured from the most recently available transthoracic echocardiography. The requirement for reintervention during follow-up was recorded. Results Between 2005 and 2018, 98 patients underwent VSRR. Sixty-six (67.3%) had Marfan syndrome or Loeys-Dietz syndrome. Median age was 60 (interquartile range, 18-68) years and 71 (72.4%) were men. Median cross-clamp and cardiopulmonary bypass times were 122 (interquartile range, 104-164) minutes and 138 (interquartile range, 121-198) minutes, respectively. Median intensive care unit and hospital stay were 1 day and 6 days, respectively. No patients suffered perioperative stroke. There was no in-hospital mortality. At median follow-up of 7.1 years (interquartile range, 5-129 months), mean postoperative annular diameter was 25.7 mm, from 24.2 mm preoperatively (P = .403). One patient required aortic valve replacement during follow-up. Freedom from moderate or severe aortic regurgitation was 97%. Conclusions There was no significant aortic annular dilatation in selected patients undergoing remodeling VSRR. Our data do not support routine use of annuloplasty in patients with annular diameter less than or equal to 25 mm