Identification and functional analysis of CG3526 in spermatogenesis of Drosophila melanogaster

Spermatogenesis is a critical part of reproduction in insects;however,its molecular mechanism is still largely unknown.In this study,we identified a testis-specific gene CG3526 in Drosophila melanogaster.Bioinformatics analysis showed that CG3526 contains a zinc binding domain and 2 C2H2 type zinc fingers,and it is clustered to the vertebrate really interesting new gene(RING)family E3 ubiquitin-protein ligases.When CG3526 was knocked down by RNA interference(RNAi),the testis became much smaller in size,and the apical tip exhibited a sharp and thin end instead of the blunt and round shape in the control testis.More importantly,compared to the control flies,only a few mature sperm were present in the seminal vesicle of C587-Gal4>CG3526 RNAi flies.Immunofluorescence staining of the testis from CG3526 RNAi flies showed that the homeostasis of testis stem cell niche was disrupted,cell distribution in the apical tip was scattered,and the process of spermatogenesis was not completed.Furthermore,we found that the phenotype of CG3526 RNAi flies’testis was similar to that of testis of Stat92E RNAi flies,the expression level of CG3526 was significantly downregulated in the Stat92EF06346 mutant flies,and the promoter activity of CG3526 was upregulated by STAT92E.Taken together,our results indicated that CG3526 is a downstream effector gene in the JAK-STAT signaling pathway that plays a key role in the spermatogenesis of Drosophila.

Effective suppression of stimulated Raman scattering in half 10 kW tandem pumping fiber lasers using chirped and tilted fiber Bragg gratings

The average power of fiber lasers has been scaled deeply into the kW regime in the past years. However, stimulated Raman scattering(SRS) is still a major factor limiting further power scaling. Here, we have demonstrated for the first time, to the best of our knowledge, the suppression of SRS in a half 10 kW tandem pumping fiber amplifier using chirped and tilted fiber Bragg gratings(CTFBGs). With specially self-designed and manufactured CTFBGs inserted between the seed laser and the amplifier stage, a maximum SRS suppression ratio of >15 dB in spectrum is observed with no reduction in laser efficiency. With one CTFBG, the effective output power is improved to3.9 kW with a beam quality M2 factor of ～1.7 from <3.5 k W with an M2 factor of >2; with two CTFBGs, the effective laser power reaches 4.2 kW with an increasing ratio of 20% and an M2 factor of ～1.8, and further power improvement is limited by the power and performance of the 1018 nm pump sources. This work provides an effective SRS suppression method for high-power all-fiber lasers, which is useful for further power scaling of these systems.

Deep learning for position fixing in the micron scale by using convolutional neural networks

We propose here a novel method for position fixing in the micron scale by combining the convolutional neural network(CNN) architecture and speckle patterns generated in a multimode fiber. By varying the splice offset between a single mode fiber and a multimode fiber, speckles with different patterns can be generated at the output of the multimode fiber. The CNN is utilized to learn these specklegrams and then predict the offset coordinate. Simulation results show that predicted positions with the precision of 2 μm account for 98.55%.This work provides a potential high-precision two-dimensional positioning method.