Doppler Frequency Estimation for a Maneuvering Target Being Tracked by Passive Radar Using Particle Filter

In this paper, we estimate Doppler frequency of a maneuvering target being tracked by passive radar using two types of particle filter, the first is “Maximum Likelihood Particle Filter” (MLPF) and the second is “Minimum Variance Particle filter” (MVPF). By simulating the passive radar system that has the bistatic geometry “Digital Video Broadcasting-Terrestrial (DVB-T) transmitter / receiver” with these two types, we can estimate the Doppler frequency of the maneuvering target and compare the simulation results for deciding which type gives better performanc

Target Coordinates Estimation by Passive Radar with a Single non-Cooperative Transmitter and a Single Receiver

Passive radar is a bistatic radar that detects and tracks targets by processing reflections from non-cooperative transmitters. Due to the bistatic geometry for this radar, a target can be localized in Cartesian coordinates by using one of the following bistatic geometries: multiple non-cooperative transmitters and a single receiver, or a single non-cooperative transmitter and multiple receivers, whereas the diversity of receivers or non-cooperative transmitters leads to extra signal processing and a ghost target phenomenon. To mitigate these two disadvantages, we present a new method to estimate Cartesian coordinates of a target by a passive radar system with a single non-cooperative transmitter and a single receiver. This method depends on the ability of the radar receiver to analyze a signal-to-noise ratio (SNR) and estimate two arrival angles for the target’s echo signal. The proposed passive radar system is simulated with a Digital Video Broadcasting-Terrestrial (DVB-T) transmitter, and the simulation results show the efficiency of this system compared with results of other researches

3D Target Localization by Using Particle Filter with Passive Radar Having one Non-cooperative Transmitter and one Receiver

In a passive radar system, localizing a target in Cartesian space is achieved by using one of the following bistatic geometries: multiple non-cooperative transmitters with one receiver, one non-cooperative transmitter with multiple receivers, or one non-cooperative transmitter with one receiver. In this paper, we propose a new method for localizing a target in Cartesian space by passive radar having the bistatic geometry “one non-cooperative transmitter and one receiver”. This method depends on using two consecutive particle filters for estimating and analyzing the Doppler frequency and time delay of the target’s echo signal. The theoretical analysis of the proposed method is presented, and its efficiency is verified by simulating the passive radar system with a Digital Video Broadcasting-Terrestrial (DVB-T) transmitter

E-Cigarette Liquid Provokes Significant Embryotoxicity and Inhibits Angiogenesis.

E-cigarette smoking (ECS) is a new method of tobacco smoking that is gaining popularity as it is thought to be a "healthy method" of tobacco consumption. The adverse outcomes of ECS on the respiratory and cardiovascular systems in humans have been recently demonstrated. Nevertheless, the effect of e-cigarette liquid (ECL) on the early stage of embryogenesis and angiogenesis has not been explored yet. Chicken embryo at 3 days of incubation and its chorioallantoic membrane (CAM) of 5 days were used to explore the outcome of ECL on the embryo. Real-time PCR was also employed to study the regulation of a set of key controller genes of embryogenesis as well as angiogenesis. Our study revealed that ECL exposure is associated with a high rate of mortality in embryos as around 70% of treated embryos, at 3 days of incubation, die after 5 days of exposure. Additionally, ECL inhibits angiogenesis of the CAM of 5 days of incubation by more than 30%. These effects could be explained by the upregulation of , and as well as the downregulation of and genes, which are important key controller genes of embryogenesis as well as angiogenesis. Our data suggest clearly that ECS can have dramatic toxic outcomes on the early stage of embryogenesis as well as angiogenesis. Accordingly, we believe that further studies to assess the effects of ECS on human health are essential.A-E-A.M’s lab is supported by grants from the Qatar University: QUHI-CMED-19/20-1, GCC # 2017- 002 QU/KU, and QUST-1-CMED-2020-2

SIGNALING PATHWAYS REGULATED BY BRASSICACEAE EXTRACT INHIBIT THE FORMATION OF ADVANCED GLYCATED END PRODUCTS IN RAT BRAIN

Background: The goal of this study was identification signaling molecules mediated the formation of AGEs in brain of rats injected with CdCl2 and the role of camel whey proteins and Brassicaceae extract on formation of AGEs in brain. Methods: Ninety male rats were randomly grouped into five groups; Normal control (GpI) and the other rats (groups II-V) were received a single dose of cadmium chloride i.p (5 μg/kg/b.w) for induction of neurodegeneration. Rats in groups III-V were treated daily with whey protein (1g/kg b.w) or Brassicaceae extract (1mg/kg b.w) or combined respectively for 12 weeks. Results: It was found that whey protein combined with Brassicaceae extract prevented the formation of AGEs and enhance the antioxidant activity compared with untreated group (

Large-Scale Recombinant Production of the SARS-CoV-2 Proteome for High-Throughput and Structural Biology Applications

The highly infectious disease COVID-19 caused by the Betacoronavirus SARS-CoV-2 poses a severe threat to humanity and demands the redirection of scientific efforts and criteria to organized research projects. The international COVID19-NMR consortium seeks to provide such new approaches by gathering scientific expertise worldwide. In particular, making available viral proteins and RNAs will pave the way to understanding the SARS-CoV-2 molecular components in detail. The research in COVID19-NMR and the resources provided through the consortium are fully disclosed to accelerate access and exploitation. NMR investigations of the viral molecular components are designated to provide the essential basis for further work, including macromolecular interaction studies and high-throughput drug screening. Here, we present the extensive catalog of a holistic SARS-CoV-2 protein preparation approach based on the consortium’s collective efforts. We provide protocols for the large-scale production of more than 80% of all SARS-CoV-2 proteins or essential parts of them. Several of the proteins were produced in more than one laboratory, demonstrating the high interoperability between NMR groups worldwide. For the majority of proteins, we can produce isotope-labeled samples of HSQC-grade. Together with several NMR chemical shift assignments made publicly available on covid19-nmr.com, we here provide highly valuable resources for the production of SARS-CoV-2 proteins in isotope-labeled form

1^1H, 13^{13}C and 15^{15}N Backbone chemical shift assignments of the n-terminal and central intrinsically disordered domains of SARS-CoV-2 nucleoprotein

International audienceThe nucleoprotein (N) from SARS-CoV-2 is an essential cofactor of the viral replication transcription complex and as such represents an important target for viral inhibition. It has also been shown to colocalize to the transcriptase-replicase complex, where many copies of N decorate the viral genome, thereby protecting it from the host immune system. N has also been shown to phase separate upon interaction with viral RNA. N is a 419 amino acid multidomain protein, comprising two folded, RNA-binding and dimerization domains spanning residues 45$-$175 and 264$-$365 respectively. The remaining 164 amino acids are predicted to be intrinsically disordered, but there is currently no atomic resolution information describing their behaviour. Here we assign the backbone resonances of the first two intrinsically disordered domains (N1, spanning residues 1$-$44 and N3, spanning residues 176$-$263). Our assignment provides the basis for the identification of inhibitors and functional and interaction studies of this essential protein

Intrinsically Disordered Tardigrade Proteins Self-Assemble into Fibrous Gels in Response to Environmental Stress.

International audienceTardigrades are remarkable for their ability to survive harsh stress conditions as diverse as extreme temperature and desiccation. The molecular mechanisms that confer this unusual resistance to physical stress remain unknown. Recently, tardigrade-unique intrinsically disordered proteins have been shown to play an essential role in tardigrade anhydrobiosis. Here, we characterize the conformational and physical behaviour of CAHS-8 from Hypsibius exemplaris. NMR spectroscopy reveals that the protein comprises an extended central helical domain flanked by disordered termini. Upon concentration, the protein is shown to successively form oligomers, long fibres, and finally gels constituted of fibres in a strongly temperature-dependent manner. The helical domain forms the core of the fibrillar structure, with the disordered termini remaining highly dynamic within the gel. Soluble proteins can be encapsulated within cavities in the gel, maintaining their functional form. The ability to reversibly form fibrous gels may be associated with the enhanced protective properties of these proteins

The intrinsically disordered SARS-CoV-2 nucleoprotein in dynamic complex with its viral partner nsp3a

International audienceThe processes of genome replication and transcription of SARS-CoV-2 represent important targets for viral inhibition. Betacoronaviral nucleoprotein (N) is a highly dynamic cofactor of the replication-transcription complex (RTC), whose function depends on an essential interaction with the amino-terminal ubiquitin-like domain of nsp3 (Ubl1). Here, we describe this complex (dissociation constant - 30 to 200 nM) at atomic resolution. The interaction implicates two linear motifs in the intrinsically disordered linker domain (N3), a hydrophobic helix ((219)LALLLLDRLNQL(230)) and a disordered polar strand ((243)GQTVTKKSAAEAS(255)), that mutually engage to form a bipartite interaction, folding N3 around Ubl1. This results in substantial collapse in the dimensions of dimeric N, forming a highly compact molecular chaperone, that regulates binding to RNA, suggesting a key role of nsp3 in the association of N to the RTC. The identification of distinct linear motifs that mediate an important interaction between essential viral factors provides future targets for development of innovative strategies against COVID-19

1H, 13C and 15N backbone chemical shift assignments of SARS-CoV-2 nsp3a

International audienceThe non-structural protein nsp3 from SARS-CoV-2 plays an essential role in the viral replication transcription complex. Nsp3a constitutes the N-terminal domain of nsp3, comprising a ubiquitin-like folded domain and a disordered acidic chain. This region of nsp3a has been linked to interactions with the viral nucleoprotein and the structure of double membrane vesicles. Here, we report the backbone resonance assignment of both domains of nsp3a. The study is carried out in the context of the international covid19-nmr consortium, which aims to characterize SARS-CoV-2 proteins and RNAs, providing for example NMR chemical shift assignments of the different viral components. Our assignment will provide the basis for the identification of inhibitors and further functional and interaction studies of this essential protein