1,770 research outputs found
Unambiguous Tracking Method Based on Combined Correlation Functions for sine/cosine-BOC CBOC and AltBOC Modulated Signals
Unambiguous tracking for Binary Offset Carrier (BOC) modulated signals is an important requirement of modern Global Navigation Satellite System (GNSS) receivers. An unambiguous tracking method based on combined correlation functions for even/odd order sine/cosine-BOC, Composite BOC(CBOC) and Alternate BOC(AltBOC) modulated signals is proposed. Firstly, a unitary mathematical formulation for all kinds of BOC modulations is introduced. Then an unambiguous tracking method is proposed based on the formulation and the idea of pseudo correlation function (PCF) method. Finally, the tracking loop based on the proposed method is designed. Simulation results indicate that the proposed method can remove side peaks while retaining the sharp main peak for all kinds of BOC modulations. The tracking performance for AltBOC is examined and the results show that the proposed method has better performance in thermal noise and long-delay multipath mitigation than the traditional unambiguous tracking methods
Theory of Electron-Phonon Dynamics in Insulating Nanoparticles
We discuss the rich vibrational dynamics of nanometer-scale semiconducting
and insulating crystals as probed by localized electronic impurity states, with
an emphasis on nanoparticles that are only weakly coupled to their environment.
Two principal regimes of electron-phonon dynamics are distinguished, and a
brief survey of vibrational-mode broadening mechanisms is presented. Recent
work on the effects of mechanical interaction with the environment is
discussed.Comment: Revte
Whole genome sequencing of a banana wild relative Musa itinerans provides insights into lineage-specific diversification of the Musa genus
Crop wild relatives are valuable resources for future genetic improvement. Here, we report the de novo genome assembly of Musa itinerans, a disease-resistant wild banana relative in subtropical China. The assembled genome size was 462.1 Mb, covering 75.2% of the genome (615.2Mb) and containing 32, 456 predicted protein-coding genes. Since the approximate divergence around 5.8 million years ago, the genomes of Musa itinerans and Musa acuminata have shown conserved collinearity. Gene family expansions and contractions enrichment analysis revealed that some pathways were associated with phenotypic or physiological innovations. These include a transition from wood to herbaceous in the ancestral Musaceae, intensification of cold and drought tolerances, and reduced diseases resistance genes for subtropical marginally distributed Musa species. Prevalent purifying selection and transposed duplications were found to facilitate the diversification of NBS-encoding gene families for two Musa species. The population genome history analysis of M. itinerans revealed that the fluctuated population sizes were caused by the Pleistocene climate oscillations, and that the formation of Qiongzhou Strait might facilitate the population downsizing on the isolated Hainan Island about 10.3 Kya. The qualified assembly of the M. itinerans genome provides deep insights into the lineage-specific diversification and also valuable resources for future banana breeding
Asymmetry Parameter of the by Analyzing the Transition Form Factors within QCD
Separating the mixture of the and states, the
transition form factors are calculated in
the three-point QCD sum rules approach. The longitudinal, transverse and total
decay widths as well as the asymmetry parameter, characterizing the
polarization of the axial and the branching ratio for these
decays are evaluated.Comment: 25 pages, 3 figures, 3 table
Targeting lentiviral vectors to antigen-specific immunoglobulins
Gene transfer into B cells by lentivectors can provide an alternative approach to managing B lymphocyte malignancies and autoreactive B cell-mediated autoimmune diseases. These pathogenic B cell Populations can be distinguished by their surface expression of monospecific immunoglobulin. Development of a novel vector system to deliver genes to these specific B cells could improve the safety and efficacy of gene therapy. We have developed an efficient rnethod to target lentivectors to monospecific immunoglobulin-expressing cells in vitro and hi vivo. We were able to incorporate a model antigen CD20 and a fusogenic protein derived from the Sindbis virus as two distinct molecules into the lentiviral Surface. This engineered vector could specifically bind to cells expressing Surface immunoglobulin recognizing CD20 (αCD20), resulting in efficient transduction of target cells in a cognate antigen-dependent manner in vitro, and in vivo in a xenografted tumor model. Tumor suppression was observed in vivo, using the engineered lentivector to deliver a suicide gene to a xenografted tumor expressing αCD20. These results show the feasibility of engineering lentivectors to target immunoglobulin-specific cells to deliver a therapeutic effect. Such targeting lentivectors also Could potentially be used to genetically mark antigen-specific B cells in vivo to study their B cell biology
Development of a multiplex event-specific PCR assay for detection of genetically modified rice
Global rice supplies have been found contaminated with unapproved varieties of genetically modified (GM) rice in recent years, which has led to product recalls in several of countries. Faster and more effective detection of GM contamination can prevent adulterated food, feed and seed from being consumed and grown, minimize the potential environmental, health or economic damage. In this study, a simple, reliable and cost-effective multiplex polymerase chain reaction (PCR) assay for identifying genetic modifications of TT51-1, Kemingdao1 (KMD1) and Kefeng6 (KF6) rice was developed by using the event-specific fragment. The limit of detection (LOD) for each event in the multiplex PCR is approximately 0.1%. Developed multiplex PCR assays can provide a rapid and simultaneous detection of GM rice
Sumoylation of LAP1 is involved in the HDAC4-mediated repression of COX-2 transcription
CEBPB, one of the CEBP family members, is a crucial regulator of gene expression during innate immunity, inflammatory responses and adipogenesis. In this study, the EGF-induced increase of CEBPB mRNA is shown to be coincident with the decrease of COX-2 mRNA. We identified that all of the individual CEBPB isoforms, LAP1, LAP2 and LIP, attenuate EGF-induced COX-2 promoter activity. Although increased sumoylation of both LAP1 and LAP2 is observed during the lagging stage of EGF treatment, only the sumoylated LAP1, but not the sumoylated LAP2, is responsible for COX-2 gene repression. In addition, EGF treatment can regulate the nucleocytoplasmic redistribution of HDAC4 and SUMO1. We further demonstrated by loss-of- and gain-of-function approaches that HDAC4 can be a negative regulator while inactivating COX-2 transcription. The sumoylation mutant LAP1, LAP1K174A, exhibits an attenuated ability to interact with HDAC4, and increased COX-2 promoter activity. Furthermore, the in vivo DNA binding assay demonstrated that LAP1K174A and CEBPDK120A, sumoylation-defective CEBPD mutants, attenuate the binding of HDAC4 on the COX-2 promoter. In light of the above, our data suggest that the suCEBPD and suLAP1 are involved in the repression of COX-2 transcription through the recruitment of HDAC4
Active screen plasma nitriding of a Si-alloyed FeCrNi medium entropy alloy:High interstitial absorption and an anomalous Si-induced decomposition mechanism in N-expanded austenite
Rare Semileptonic Decays of Heavy Mesons with Flavor SU(3) Symmetry
In this paper, we calculate the decay rates of , , , and
semileptonic decay processes, in which only the light
quarks decay, while the heavy flavors remain unchanged. The branching ratios of
these decay processes are calculated with the flavor SU(3) symmetry. The
uncertainties are estimated by considering the SU(3) breaking effect. We find
that the decay rates are very tiny in the framework of the Standard Model. We
also estimate the sensitivities of the measurements of these rare decays at the
future experiments, such as BES-III, super- and LHC-.Comment: 4 pages and 1 figure, accepted by European Physical Journal
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