An improved Autogram and MOMEDA method to detect weak compound fault in rolling bearings.

When weak compound fault occurs in rolling bearing, the faint fault features suffer from serious noise interference, and different type faults are coupled together, making it a great challenge to separate the fault features. To solve the problems, a novel weak compound fault diagnosis method for rolling bearing based on improved Autogram and multipoint optimal minimum entropy deconvolution adjusted (MOMEDA) is proposed. Firstly, the kurtosis index in Autogram is modified with multi-scale permutation entropy, and improved Autogram finds the optimal resonance frequency band to preliminarily denoise the weak compound fault signal. Then, MOMEDA is performed to deconvolute the denoised signal to decouple the features of compound fault. Finally, square envelope analysis is applied on the separated deconvoluted signals to identify different type faults according to the fault characteristic frequencies in the spectrums. The proposed method is performed to analyze the simulated signal and experimental datasets of different types of rolling bearing weak compound faults. The results indicate that the proposed method can accurately diagnose the weak compound faults, and comparison with the analysis results of parameter-adaptive variational mode decomposition algorithm verifies its effectiveness and superiority.

Identification and characterization of An-4, a potential quantitative trait locus for awn development in rice.

BACKGROUND: Awn of rice is an important domestication trait closely associated with yield traits. Therefore, the identification of genes for awn development is of great significance for the elucidation of molecular mechanism of awn development and the genetic improvement of yield traits in rice. RESULTS: In this study, using chromosome segment substitution lines (CSSLs) derived from a long-awned Guangxi common wild rice (GXCWR, Oryza rufipogon Griff.) and a short-awned indica cultivar 9311, we identified An-4, a potential quantitative trait locus (QTL) for awn development. Then, An-4 was fine mapped into a 56-kb region of chromosome 2, which contained four annotated genes. Among these four annotated genes, Os02g0594800 was concluded to be the potential candidate gene for An-4. An-4 exhibited pleiotropic effects on awn development and several yield traits. Scanning electron microscopy (SEM) analysis showed that An-4 significantly promoted awn development at Sp7 and Sp8 stage of spikelet development. Transcriptome analysis suggested that An-4 might influence the development of awn by regulating the expression of genes related to growth, developmental process, channel regulation and extracellular region. By contrast to those of 9311, the expression level of OsRR5 in CSSL128 was significantly down-regulated, whereas the expression levels of OsCKX2 and OsGA2ox5 in CSSL128 were significantly up-regulated. In addition, our study showed that An-4 had additive effects with other genes for awn development, such as An-1, An-2/LABA1 and An-3/GAD1/RAE2. CONCLUSIONS: The identification of An-4 lays a foundation for cloning of An-4 and further elucidation of the molecular mechanism of awn development. Moreover, the identification of favorable allelic variation of An-4 from 9311 will be useful to improve rice yield traits.

Response of Anammox biofilm to antibiotics in trace concentration: Microbial activity, diversity and antibiotic resistance genes.

Long-term impacts of two antibiotics-norfloxacin (NOR) and erythromycin (ERY) in trace concentration (1ug L-1) on Anammox biofilm were investigated. The specific Anammox activity (SAA) and dehydrogenase activity (DHA) of Anammox biofilm were detected by batch experiments, the microbial diversity was analyzed using high-throughput sequencing technology and the antibiotic resistance genes (ARGs) were measured by qPCR. Results showed that long-term NOR feeding decreased 30% SAA and 39.6% DHA, and also decreased the abundance of the OTUs related to autotrophic nitrogen removal, while ERY had slight impact on Anammox. Only two ARGs targeted to ERY (ermB, mphA) were detected in the two Anammox systems while those targeted to NOR (qnrA, qnrB, qnrD, and qnrS) were not detected. The relative expression of ermB to 16S rRNA increased from 2.08±0.32×10-4 to 3.53±1.18×10-4, and that of mphA increased to 5.00±0.48×10-4 from 4.48±1.32×10-5. The induced ARGs in the Anammox system help it resist the ERY shock.