Focusing on the vertical array source signal recovery method, aiming at the estimation deviation caused by environment mismatch in the engineering application of virtual time reversal mirror technology, this paper proposes the normalized virtual time reversal technology through theoretical derivation and analyzes the performance of the virtual time reversal technology under the change of environment and signal-to-noise ratio through simulation. Finally, the practicability of the normalized virtual time reversal method and the effectiveness of model correction are verified through experimental data. The data processing results show that the source level estimation error of vertical array based on normalized virtual time reversal algorithm is less than 5.2dB. In the experimental environment of this paper, the correlation of signal spectral structure recovered by this method is about 5% higher than that by the traditional method.

ABSTRACT. The neonatal Fc receptor (FcRn) plays an important role in regulating IgG homeostasis in the body and passive protection to the offspring. Changes in FcRn expression levels caused by genetic polymorphisms of Fcgrt, which encodes FcRn, may lead to interindividual differences in colostrum IgG levels in sheep. In this study, we sequenced the FcRn partial heavy chain from 179 sheep from Xinjiang Province, China, and detected the differences in colostrum IgG levels and Fcgrt genotypes to identify the correlation between the Fcgrt genotype and colostrum IgG levels in 4 sheep breeds. The DNA sequencing of a 680-bp fragment of the Fcgrt gene revealed various patterns depending on the single-strand conformation in the Suffolk breed. Sequencing analysis revealed a total of 3 patterns, AA, BB, AB, in this fragment, among which the absence of AB and BB genotype acted as a marker for breed identification and characterization, while the AA genotype was shared by Suffolk and 3 other breeds. The only allele found in all 4 breeds was allele A, indicating that natural selection may be favoring the AB and BB genotypes in general and B allele in particular, as the colostrum IgG concentration was relatively higher in the Suffolk breed compared to the other 3 breeds.

To evaluate the genetic polymorphisms and to search for available molecular markers for Liangshan semi-wool sheep, 15 microsatellite markers of 187 samples were amplified by multiplex PCR. A total of 133 alleles were detected, with the number of alleles ranging from 6 (BM2830) to 15 (McM130), giving a mean No. of 8.87 alleles per locus. The total and mean effective allele No. were 64.29 and 4.29, respectively. The observed heterozygosity and expected heterozygosity were from 0.4486 (McM130) to 0.8877 (BMS1678) and 0.5704 (BMS0887) to 0.8373 (McM130), respectively. Mean observed heterozygosity and mean expected heterozygosity were 0.672 and 0.7536. Polymorphism information content values were from 0.5202 (BMS0887) to 0.8183 (McM130) and mean polymorphism information content of the 15 microsatellite loci was 0.7184. All 15 microsatellite loci were highly polymorphic, which showed that there were rich genetic polymorphisms at these detected microsatellite loci in Liangshan semi-wool sheep. Comparison of allele distributions among loci did not reveal consistent shapes. Distributions were centralized in some cases, whereas in others some kind of skewness was evident. Complex evolution at these loci is an important factor in the irregularity of microsatellite distributions.