Harmonicity Spectrum

Perceiving harmonic information (especially weak harmonic information) in time series has important scientific and engineering significance. Fourier spectrum and time-frequency spectrum are commonly used tools for perceiving harmonic information, but they are often ineffective in perceiving weak harmonic signals because they are based on energy or amplitude analysis. Based on the theory of Normal time-frequency transform (NTFT) and complex correlation coefficient, a new type of spectrum, the Harmonicity Spectrum (HS), is developed to perceive harmonic information in time series. HS is based on the degree of signal harmony rather than energy or amplitude analysis, and can therefore perceive very weak harmonic information in signals sensitively. Simulation examples show that HS can detect harmonic information that cannot be detected by Fourier spectrum or time-frequency spectrum. Acoustic data analysis shows that HS has better resolution than traditional LOFAR spectrum.

Glancing incidence x-ray fluorescence spectrometry based on a single-bounce parabolic capillary

Glancing incidence x-ray fluorescence spectrometry using a single-bounce parabolic capillary is proposed for the analysis of layered samples.The divergence of the x-ray beam was 0.33 mrad.In this paper,we used this instrumental setup to analyze a Si single crystal and a 50 nm HfO_(2) single-layer film deposited on a Si substrate.

Identification and characterization of genes related to m^(6)A modification in kiwifruit using RNA-seq and ATAC-seq

N6-methyladenosine(m^(6)A)RNA modification is a conserved mechanism that regulates the fate of RNA across eukaryotic organisms.Despite its significance,a comprehensive analysis of m^(6)A-related genes in non-model plants,such as kiwifruit,is lacking.Here,we identified 36 m^(6)A-related genes in the kiwifruit genome according to homology and phylogenetic inference.We performed bioinformatics and evolutionary analyses of the writer,eraser,and reader families of m^(6)A modification.Reanalysis of public RNA-seq data collected from samples under various biotic and abiotic stresses indicated that most m^(6)A-related genes were remarkably expressed under different conditions.Through construction of gene co-expression networks,we found significant correlations between several m^(6)A-related genes and transcription factors(TFs)as well as receptor-like genes during the development and ripening of kiwifruit.Furthermore,we performed ATAC-seq assays on diverse kiwifruit tissues to investigate the regulatory mechanisms of m^(6)A-related genes.We identified 10 common open chromatin regions that were present in at least two tissues,and these regions might serve as potential binding sites for MADS protein,C2H2 protein,and other predicted TFs.Our study offers comprehensive insights into the gene family of m^(6)A-related components in kiwifruit,which will lay foundation for exploring mechanisms of post-transcriptional regulation involved in development and adaptation of kiwifruit.

Genomic insights into the origin, adaptive evolution, and herbicide resistance of Leptochloa chinensis, a devastating tetraploid weedy grass in rice fields

Chinese sprangletop (Leptochloa chinensis), belonging to the grass subfamily Chloridoideae, is one of the most notorious weeds in rice ecosystems. Here, we report a chromosome-scale reference genome assembly and a genomic variation map of the tetraploid L. chinensis. The L. chinensis genome is derived from two diploid progenitors that diverged ∼10.9 million years ago, and its two subgenomes display neither fractionation bias nor overall gene expression dominance. Comparative genomic analyses reveal substantial genome rearrangements in L. chinensis after its divergence from the common ancestor of Chloridoideae and, together with transcriptome profiling, demonstrate the important contribution of tetraploidization to the gene sources for the herbicide resistance of L. chinensis. Population genomic analyses of 89 accessions from China reveal that L. chinensis accessions collected from southern/southwestern provinces have substantially higher nucleotide diversity than those from the middle and lower reaches of the Yangtze River, suggesting that L. chinensis spread in China from the southern/southwestern provinces to the middle and lower reaches of the Yangtze River. During this spread, L. chinensis developed significantly increased herbicide resistance, accompanied by the selection of numerous genes involved in herbicide resistance. Taken together, our study generated valuable genomic resources for future fundamental research and agricultural management of L. chinensis, and provides significant new insights into the herbicide resistance as well as the origin and adaptive evolution of L. chinensis.