118 research outputs found
Empirical Comparison of Chirp and Multitones on Experimental UWB Software Defined Radar Prototype
This paper proposes and tests an approach for an unbiased study of radar waveforms' performances. Using the ultrawide band software defined radar prototype, the performances of Chirp and Multitones are compared in range profile and detection range. The architecture was implemented and has performances comparable to the state of the art in software defined radar prototypes. The experimental results are consistent with the simulations
Empirical Comparison of Chirp and Multitones on Experimental UWB Software Defined Radar Prototype
This paper proposes and tests an approach for an unbiased study of radar waveforms' performances. Using the ultrawide band software defined radar prototype, the performances of Chirp and Multitones are compared in range profile and detection range. The architecture was implemented and has performances comparable to the state of the art in software defined radar prototypes. The experimental results are consistent with the simulations
Case Study Analysis of Linear Chirp and Multitones (OFDM) Radar Signals Through Simulations and Measurement with HYCAM-Research Test Bench
This paper presents a experimental platform that allows comparing objectively any radar waveforms. This is realized by equating radar characteristics, using the same test-bench HYCAM-Research, the same signal processing and also insuring the reproducibility of the experiments. The experimental measurements on linear chirp and multitones are analyzed through distance and velocity imaging
Embedded real-time monitoring using SystemC in IMA network
Avionics is one kind of domain where prevention prevails. Nonetheless fails
occur. Sometimes due to pilot misreacting, flooded in information. Sometimes
information itself would be better verified than trusted. To avoid some kind of
failure, it has been thought to add,in midst of the ARINC664 aircraft data
network, a new kind of monitoring
Case Study Analysis of Linear Chirp and Multitones (OFDM) Radar Signals Through Simulations and Measurement with HYCAM-Research Test Bench
This paper presents a experimental platform that allows comparing objectively any radar waveforms. This is realized by equating radar characteristics, using the same test-bench HYCAM-Research, the same signal processing and also insuring the reproducibility of the experiments. The experimental measurements on linear chirp and multitones are analyzed through distance and velocity imaging
Differential binding regulation of microtubule-associated proteins MAP1A, MAP1B, and MAP2 by tubulin polyglutamylation.
The major neuronal post-translational modification of tubulin, polyglutamylation, can act as a molecular potentiometer to modulate microtubule-associated proteins (MAPs) binding as a function of the polyglutamyl chain length. The relative affinity of Tau, MAP2, and kinesin has been shown to be optimal for tubulin modified by approximately 3 glutamyl units. Using blot overlay assays, we have tested the ability of polyglutamylation to modulate the interaction of two other structural MAPs, MAP1A and MAP1B, with tubulin. MAP1A and MAP2 display distinct behavior in terms of tubulin binding; they do not compete with each other, even when the polyglutamyl chains of tubulin are removed, indicating that they have distinct binding sites on tubulin. Binding of MAP1A and MAP1B to tubulin is also controlled by polyglutamylation and, although the modulation of MAP1B binding resembles that of MAP2, we found that polyglutamylation can exert a different mode of regulation toward MAP1A. Interestingly, although the affinity of the other MAPs tested so far decreases sharply for tubulins carrying long polyglutamyl chains, the affinity of MAP1A for these tubulins is maintained at a significant level. This differential regulation exerted by polyglutamylation toward different MAPs might facilitate their selective recruitment into distinct microtubule populations, hence modulating their functional properties
WiNoCoD : Un réseau d'interconnexion hiérarchique RF pour les MPSoC
International audienceLa multiplication du nombre de cœurs de calcul présents sur les puces va de pair avec une augmentation des besoins en communication. C'est pour palier à ce problème que nous présentons dans cette article un réseau d'interconnexion sur puce utilisant la RF. Nous présentons les raisons du choix de la RF par rapport aux autres nouvelles technologies du domaine que sont l'optique et la 3D, l'architecture détaillée de ce réseau et d'une puce le mettant en œuvre ainsi que l'évaluation de sa faisabilité et de ses performances. Un des avantages potentiels de ce réseau d'interconnexion RF est la possibilité de faire du broadcast à faible coût, ce qui ouvre de nouvelles perspectives notamment en terme de gestion de la cohérence mémoire
L-Ilf3 and L-NF90 Traffic to the Nucleolus Granular Component: Alternatively-Spliced Exon 3 Encodes a Nucleolar Localization Motif
Ilf3 and NF90, two proteins containing double-stranded RNA-binding domains, are generated by alternative splicing and involved in several functions. Their heterogeneity results from posttranscriptional and posttranslational modifications. Alternative splicing of exon 3, coding for a 13 aa N-terminal motif, generates for each protein a long and short isoforms. Subcellular fractionation and localization of recombinant proteins showed that this motif acts as a nucleolar localization signal. Deletion and substitution mutants identified four arginines, essential for nucleolar targeting, and three histidines to stabilize the proteins within the nucleolus. The short isoforms are never found in the nucleoli, whereas the long isoforms are present in the nucleoplasm and the nucleoli. For Ilf3, only the posttranslationally-unmodified long isoform is nucleolar, suggesting that this nucleolar targeting is abrogated by posttranslational modifications. Confocal microscopy and FRAP experiments have shown that the long Ilf3 isoform localizes to the granular component of the nucleolus, and that L-Ilf3 and L-NF90 exchange rapidly between nucleoli. The presence of this 13 aminoacid motif, combined with posttranslational modifications, is responsible for the differences in Ilf3 and NF90 isoforms subcellular localizations. The protein polymorphism of Ilf3/NF90 and the various subcellular localizations of their isoforms may partially explain the various functions previously reported for these proteins
High-Efficient Generation of Induced Pluripotent Stem Cells from Human Astrocytes
The reprogramming of human somatic cells to induced pluripotent stem (hiPS) cells enables the possibility of generating patient-specific autologous cells for regenerative medicine. A number of human somatic cell types have been reported to generate hiPS cells, including fibroblasts, keratinocytes and peripheral blood cells, with variable reprogramming efficiencies and kinetics. Here, we show that human astrocytes can also be reprogrammed into hiPS (ASThiPS) cells, with similar efficiencies to keratinocytes, which are currently reported to have one of the highest somatic reprogramming efficiencies. ASThiPS lines were indistinguishable from human embryonic stem (ES) cells based on the expression of pluripotent markers and the ability to differentiate into the three embryonic germ layers in vitro by embryoid body generation and in vivo by teratoma formation after injection into immunodeficient mice. Our data demonstrates that a human differentiated neural cell type can be reprogrammed to pluripotency and is consistent with the universality of the somatic reprogramming procedure
Tubulin isoform composition tunes microtubule dynamics
Microtubules polymerize and depolymerize stochastically, a behavior essential for cell division, motility and differentiation. While many studies advanced our understanding of how microtubule-associated proteins tune microtubule dynamics in trans, we have yet to understand how tubulin genetic diversity regulates microtubule functions. The majority of in vitro dynamics studies are performed with tubulin purified from brain tissue. This preparation is not representative of tubulin found in many cell types. Here we report the 4.2Å cryo-EM structure and in vitro dynamics parameters of α1B/βI+βIVb microtubules assembled from tubulin purified from a human embryonic kidney cell line with isoform composition characteristic of fibroblasts and many immortalized cell lines. We find that these microtubules grow faster and transition to depolymerization less frequently compared to brain microtubules. Cryo-EM reveals that the dynamic ends of α1B/βI+βIVb microtubules are less tapered and that these tubulin heterodimers display lower curvatures. Interestingly, analysis of EB1 distributions at dynamic ends suggests no differences in GTP cap sizes. Lastly, we show that the addition of recombinant α1A/βIII tubulin, a neuronal isotype overexpressed in many tumors, proportionally tunes the dynamics of α1B/βI+βIVb microtubules. Our study is an important step towards understanding how tubulin isoform composition tunes microtubule dynamics
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