357 research outputs found

    On the validity of ADM formulation in 2D quantum gravity

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    We investigate 2d gravity quantized in the ADM formulation, where only the loop length l(z)l(z) is retained as a dynamical variable of the gravitation, in order to get an intuitive physical insight of the theory. The effective action of l(z)l(z) is calculated by adding scalar fields of conformal coupling, and the problems of the critical dimension and the time development of ll are addressed.Comment: 12 page

    Demonstration of 2.65 / 3.3 Gbit per sec X Band Radiowave Down Link Communications from LEO Small Satellite

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    This paper reports our new communication system and downlink demonstrations with a small satellite of 2.65 Gbps data rate with 64 APSK modulation and 3.3Gbps data rate with 256 APSK modulation by utilizing two circular polarization channels of X band. We have developed an on-board X-band transmitter, an on-board dual circularly polarized-wave antenna with 17dBi gain and \u3e37dB Cross Polarization Discrimination (XPD) and a 10m ground station with 39dB/K of G/T and \u3e37dB XPD for low-crosstalk polarization multiplexing. Since there are not real- time demodulator systems in such high communication speed, the downlinked signals are stored in a data recorder at an antenna site. Afterwards, we decode downlinked signals by using our non-real-time software demodulator. The system was demonstrated in orbit the RAPid Innovative payload demonstration Satellite (RAPIS-1) of JAXA in 2019. We have achieved 2.65 Gbps and 3.3Gbps communication speed in the X-band for LEO satellite at 300 M symbols per second (Msps) and polarization multiplexing of 64APSK (coding rate 4/5) and 256APSK (coding rate 3/4) following DVB-S2X protocol with roll-off factor α=0.05. The communication speeds correspond to of frequency efficiency 8.4 bit/s/Hz and 10.8 bit/s/Hz of frequency utilization efficiency. As far as authors know, these direct downlink communication speeds and frequency utilization efficiencies are the highest ones at present in LEO satellites, excluding bent-pipe communication systems

    In Silico Study of Rett Syndrome Treatment-Related Genes, MECP2, CDKL5, and FOXG1, by Evolutionary Classification and Disordered Region Assessment

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    Rett syndrome (RTT), a neurodevelopmental disorder, is mainly caused by mutations in methyl CpG-binding protein 2 (MECP2), which has multiple functions such as binding to methylated DNA or interacting with a transcriptional co-repressor complex. It has been established that alterations in cyclin-dependent kinase-like 5 (CDKL5) or forkhead box protein G1 (FOXG1) correspond to distinct neurodevelopmental disorders, given that a series of studies have indicated that RTT is also caused by alterations in either one of these genes. We investigated the evolution and molecular features of MeCP2, CDKL5, and FOXG1 and their binding partners using phylogenetic profiling to gain a better understanding of their similarities. We also predicted the structural order–disorder propensity and assessed the evolutionary rates per site of MeCP2, CDKL5, and FOXG1 to investigate the relationships between disordered structure and other related properties with RTT. Here, we provide insight to the structural characteristics, evolution and interaction landscapes of those three proteins. We also uncovered the disordered structure properties and evolution of those proteins which may provide valuable information for the development of therapeutic strategies of RTT

    Gas-flow simulation with contact moving in GCB considering high-pressure and high-temperature transport properties of SF6 gas

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    金沢大学工学部This paper addresses a thermal gas-flow simulation in gas circuit-breaker (GCB) chambers, introducing SF6 gas constants up to a pressure of 10 MPa and to a temperature of 30 000 K. In the simulation, moving parts, such as nozzle, movable arcing contact, and operating rod, are moved with the opening motion of GCB to see if different results are produced from the conventional simulation method, in which fixed parts in the real GCB are moved. As a result, as far as the pressure profile in the puffer chamber is concerned, it is confirmed that this simulation method can produce better results than the conventional method for the hybrid-puffer-type chamber. © 2005 IEEE

    Identification of endogenous small peptides involved in rice immunity through transcriptomics- and proteomics-based screening

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    Small signalling peptides, generated from larger protein precursors, are important components to orchestrate various plant processes such as development and immune responses. However, small signalling peptides involved in plant immunity remain largely unknown. Here, we developed a pipeline using transcriptomics- and proteomics-based screening to identify putative precursors of small signalling peptides: small secreted proteins (SSPs) in rice, induced by rice blast fungus Magnaporthe oryzae and its elicitor, chitin. We identified 236 SSPs including members of two known small signalling peptide families, namely rapid alkalinization factors and phytosulfokines, as well as many other protein families that are known to be involved in immunity, such as proteinase inhibitors and pathogenesis-related protein families. We also isolated 52 unannotated SSPs and among them, we found one gene which we named immune response peptide (IRP) that appeared to encode the precursor of a small signalling peptide regulating rice immunity. In rice suspension cells, the expression of IRP was induced by bacterial peptidoglycan and fungal chitin. Overexpression of IRP enhanced the expression of a defence gene, PAL1 and induced the activation of the MAPKs in rice suspension cells. Moreover, the IRP protein level increased in suspension cell medium after chitin treatment. Collectively, we established a simple and efficient pipeline to discover SSP candidates that probably play important roles in rice immunity and identified 52 unannotated SSPs that may be useful for further elucidation of rice immunity. Our method can be applied to identify SSPs that are involved not only in immunity but also in other plant functions

    Spectroscopic and thermal characterization of alternative model biomembranes from shed skins of Bothrops jararaca and Spilotis pullatus

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    Recently, there has been an interest in the use of shed snake skin as alternative model biomembrane for human stratum corneum. This research work presented as objective the qualitative characterization of alternative model biomembranes from Bothrops jararaca and Spilotis pullatus by FT-Raman, PAS-FTIR and DSC. The employed biophysical techniques permitted the characterization of the biomembranes from shed snake skin of B. jararaca and S. pullatus by the identification of vibrational frequencies and endothermic transitions that are similar to those of the human stratum corneum.Existe atualmente interesse no uso da muda de pele de cobra como modelos alternativos de biomembranas da pele humana. O presente trabalho apresentou como objetivo a caracterização qualitativa de modelos alternativos de biomembranas provenientes de mudas de pele de cobra da Bothrops jararaca e Spilotis pullatus por espectroscopia Raman (FT-Raman), espectroscopia fotoacústica no infravermelho (PAS-FTIR) e calorimetria exploratória diferencial (DSC). As técnicas biofísicas FT-Raman, PAS-FTIR e DSC permitiram caracterizar qualitativamente os modelos alternativos de biomembranas provenientes das mudas de pele de cobra da B. jararaca e S. pullatus e identificar freqüências vibracionais e transições endotérmicas similares ao estrato córneo humano

    Effects of nonionic surfactant lauryl alcohol ethoxylated on stratum corneum alternative model biomembranes evaluated by biophysical techniques

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    The influence of the nonionic surfactant lauryl alcohol ethoxylate with 12 moles ethylene oxide (LAE-12OE) was evaluated on the Stratum corneum model biomembrane (SCMM) of shed snake skin (Bothrops jararaca and Spilotes pullatus) through the biophysical techniques Fourier transform Raman spectroscopy (FT-Raman) and Fourier transform infrared photoacoustic spectroscopy (PAS-FTIR). The surfactant was used in aqueous solutions above and below the critical micelle concentration (cmc), 50.0 and 0.21 g/L, respectively. The SCMM samples were pre-treated for periods of 8 h (whole SCMM) and for 12 h (SCMM after tape stripping procedure). The LAE-12OE did not promote increase in the hydration of the B. jararaca and S. pullatus SCMM but exhibited some action as far as lipid extraction.Colegio de Farmacéuticos de la Provincia de Buenos Aire

    An NLR paralog Pit2 generated from tandem duplication of Pit1 fine-tunes Pit1 localization and function

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    NLR family proteins act as intracellular receptors. Gene duplication amplifies the number of NLR genes, and subsequent mutations occasionally provide modifications to the second gene that benefits immunity. However, evolutionary processes after gene duplication and functional relationships between duplicated NLRs remain largely unclear. Here, we report that the rice NLR protein Pit1 is associated with its paralogue Pit2. The two are required for the resistance to rice blast fungus but have different functions: Pit1 induces cell death, while Pit2 competitively suppresses Pit1-mediated cell death. During evolution, the suppression of Pit1 by Pit2 was probably generated through positive selection on two fate-determining residues in the NB-ARC domain of Pit2, which account for functional differences between Pit1 and Pit2. Consequently, Pit2 lost its plasma membrane localization but acquired a new function to interfere with Pit1 in the cytosol. These findings illuminate the evolutionary trajectory of tandemly duplicated NLR genes after gene duplication
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