162 research outputs found
New method for initial density reconstruction
A theoretically interesting and practically important question in cosmology is the reconstruction of the initial density distribution provided a late-time density field. This is a long-standing question with a revived interest recently, especially in the context of optimally extracting the baryonic acoustic oscillation (BAO) signals from observed galaxy distributions. We present a new efficient method to carry out this reconstruction, which is based on numerical solutions to the nonlinear partial differential equation that governs the mapping between the initial Lagrangian and final Eulerian coordinates of particles in evolved density fields. This is motivated by numerical simulations of the quartic Galileon gravity model, which has similar equations that can be solved effectively by multigrid Gauss-Seidel relaxation. The method is based on mass conservation, and does not assume any specific cosmological model. Our test shows that it has a performance comparable to that of state-of-the-art algorithms that were very recently put forward in the literature, with the reconstructed density field over ∼80% (50%) correlated with the initial condition at k ≲ 0.6 h=Mpc (1.0 h=Mpc). With an example, we demonstrate that this method can significantly improve the accuracy of BAO reconstruction
Rough fractional integral and its multilinear commutators on p-adic generalized Morrey spaces
In this paper, we establish the boundedness of rough -adic fractional integral operators on -adic generalized Morrey spaces, as well as the boundedness of multilinear commutators generated by rough -adic fractional integral operator and -adic generalized Campanato functions. Moreover, the boundedness in classical Morrey is given as corollaries
Genome-wide association analysis revealed genetic variation and candidate genes associated with the yield traits of upland cotton under drought conditions
Drought is one of the major abiotic stresses seriously affecting cotton yield. At present, the main cotton-producing areas in China are primarily arid and semiarid regions. Therefore, the identification of molecular markers and genes associated with cotton yield traits under drought conditions is of great importance for stabilize cotton yield under such conditions. In this study, resequencing data were used to conduct a genome-wide association study (GWAS) on 8 traits of 150 cotton germplasms. Under drought stress, 18 SNPs were significantly correlated with yield traits (single-boll weight (SBW) and seed (SC)), and 8 SNPs were identified as significantly correlated with effective fruit shoot number (EFBN) traits (a trait that is positively correlated with yield). Finally, a total of 15 candidate genes were screened. The combined results of the GWAS and transcriptome data analysis showed that four genes were highly expressed after drought stress, and these genes had significantly increased expression at 10, 15 and 25 DPA of fiber development. qRT-PCR was performed on two samples with drought tolerance extremes (drought-resistant Xinluzao 45 and drought-sensitive Xinluzao 26), revealing that three of the genes had the same differential expression pattern. This study provides a theoretical basis for the genetic analysis of cotton yield traits under drought stress, and provides gene resources for improved breeding of cotton yield traits under drought stress
Anti-parity-time topologically undefined state
We constructed an anti-parity-time-symmetric photonic lattice by using
perturbations. The results show the topological state will appear when the
waveguide coupling constants ; Interestingly, a state with
undefined winding numbers occurs when , in which the light
distributes only in the wide waveguides with equal magnitude distribution.
Further studies show that the edge state will be strengthened by introducing
defect for the topologically non-trivial case, while it will not affect the
equal intensity transmission for the topologically undefined state. Our work
provides a new way to realize the topological state and equally divided light
transmission and might be applicable in optical circuits and optical
interconnect
Variations in growth traits and wood physicochemical properties among Pinus koraiensis families in Northeast China
This study aimed to explore and improve the different economic values of Pinus koraiensis (Siebold and Zucc.) by examining the variations in 6 growth traits and 9 physicochemical wood properties among 53 P. koraiensis half-sib families. Growth traits assessed included height, diameter at breast height, volume, degree of stem straightness, stem form, and branch number per node, while wood properties assessed included density, fiber length and width, fiber length to width ratio, and cellulose, hemicellulose, holocellulose, lignin, and ash contents. Except for degree of stem straightness and branch number per node, all other traits exhibited highly significant variations (P < 0.01) among families. The coefficients of variation ranged from 5.3 (stem form) to 66.7% (ash content), whereas, the heritability ranged from 0.136 (degree of stem straightness) to 0.962 (ash content). Significant correlations were observed among growth traits and wood physicochemical properties. Principal component analysis identified four distinct groups representing growth traits, wood chemical and physical properties, and stem form traits. Multi-trait comprehensive evaluation identified three groups of elite families based on breeding objectives, including rapid growth, improved timber production for building and furniture materials, and pulpwood production. These specific families should be used to establish new plantations
Neural Stem Cells Expressing bFGF Reduce Brain Damage and Restore Sensorimotor Function after Neonatal Hypoxia-Ischemia
- …