Cloning and expression of lin-28 homolog B gene in the onset of puberty in Duolang sheep

Feng Xing,Chaoyang Zhang,Zhengquan Kong 아세아·태평양축산학회 2019 Animal Bioscience Vol.32 No.1

Objective: Recent studies have demonstrated that lin-28 homolog B (LIN28B)/miRNA let-7 (let-7) plays a role in the regulation of pubertal onset in mammals. However, the role of LIN28B/let-7 in the onset of ovine puberty remains unknown. We cloned the Duolang sheep Lin28B cDNA sequence, detected the expression change of LIN28B, let-7a and let-7g in hypothalamus, pituitary and ovary tissues at three different pubertal stages. Methods: The reverse transcriptase polymerase chain reaction (RT-PCR) was used to clone the cDNA sequence of LIN28B gene from Duolang sheep and the bioinformatics methods were applied to analyze the amino acid sequence of LIN28B protein. The mRNA expression levels of the LIN28B gene at different pubertal stages were examined by real time RT-PCR. Results: LIN28B cDNA of Duolang sheep was cloned, and two transcripts were obtained. The amino acid sequence of transcript 1 shares 99.60%, 98.78%, and 94.80% identity with those of goat, wild yak and pig, respectively. Strong LIN28B mRNA expression was detected in the hypothalamus, pituitary, ovary, oviduct and uterus, while moderate expression was found in the liver, kidney, spleen and heart, weak expression was observed in the heart. No expression was found in the lungs. Quantitative real-time PCR (QPCR) and western-blot analysis revealed that the LIN28B was highly expressed in the hypothalamus and ovary at prepuberty stages, and this expression significantly decreased from the prepuberty to puberty stages (p<0.05). Markedly increased levels of mRNA expression were detected in the pituitary from prepuberty to puberty (p<0.05) and then significantly decreased from puberty to postpuberty (p<0.05). The expression levels of let-7a and let-7g showed no significant changes among different pubertal stages (p>0.05). Conclusion: These results provided a foundation for determining the functions of LIN28B/let-7 and their role in the onset of sheep puberty.

Coordinated Control Strategies with and without Circulating Current in Unified Power Quality

Feng, Xing-tian,Zhang, Zhi-hua The Korean Institute of Power Electronics 2015 JOURNAL OF POWER ELECTRONICS Vol.15 No.5

Under traditional unified power quality conditioner (UPQC) control, a UPQC series converter (SC) is mainly used to handle grid-side power quality problems while its parallel converter (PC) is mainly used to handle load-side power quality problems. The SC and PC are relatively independent. The SC is usually in standby mode and it only runs when the grid voltage abruptly changes. In this paper, novel UPQC coordinated control strategies are proposed which use the SC to share the reactive power compensation function of the PC especially without grid-side power quality problems. However, in some cases, there will be a circulating current between the SC and the PC, which will probably influence the compensation fashion, the compensation capacity, or the normal work of the UPQC. Through an active power circulation analysis, strategies with and without a circulating current are presented which fuses the reactive power allocation strategy of the SC and the PC, the composite control strategy of the SC and the compensation strategy of the DC storage unit. Both of the strategies effectively solve the SC long term idle problem, limit the influence of the circulating current, optimize all of the UPQC units and reduce the production cost. An analysis, along with simulation andexperimental results, is presented to verify the feasibility and effectiveness of the proposed control strategies.

Coordinated Control Strategies with and without Circulating Current in Unified Power Quality Conditioners

Xing-tian Feng,Zhi-hua Zhang 전력전자학회 2015 JOURNAL OF POWER ELECTRONICS Vol.15 No.5

Under traditional unified power quality conditioner (UPQC) control, a UPQC series converter (SC) is mainly used to handle grid-side power quality problems while its parallel converter (PC) is mainly used to handle load-side power quality problems. The SC and PC are relatively independent. The SC is usually in standby mode and it only runs when the grid voltage abruptly changes. In this paper, novel UPQC coordinated control strategies are proposed which use the SC to share the reactive power compensation function of the PC especially without grid-side power quality problems. However, in some cases, there will be a circulating current between the SC and the PC, which will probably influence the compensation fashion, the compensation capacity, or the normal work of the UPQC. Through an active power circulation analysis, strategies with and without a circulating current are presented which fuses the reactive power allocation strategy of the SC and the PC, the composite control strategy of the SC and the compensation strategy of the DC storage unit. Both of the strategies effectively solve the SC long term idle problem, limit the influence of the circulating current, optimize all of the UPQC units and reduce the production cost. An analysis, along with simulation and experimental results, is presented to verify the feasibility and effectiveness of the proposed control strategies.

Integrated Protection Unit Design for Power Networks

Zhan-feng Fan,Sheng-ming Ge,Z Q Bo,Lin Wang,Feng-quan Zhou,Xing Liu,Guo-bing Song 보안공학연구지원센터 2016 International Journal of Grid and Distributed Comp Vol.9 No.4

This paper presents an hardware design solution for integrated protection of distribution systems (Network Protection Unit) by combining transient polarity comparison technique, which is based on the detection and processing of fault generated transient current signals. The integrated protection relays installed at each substation of a distribution network are communicated with the Network Protection Unit through specially designed Packet Transport Network (PTN) for fast and reliable transmission of transient polarity current signals. The relay detects the faulted generated super-imposed current signals. The transient polarity identification algorithm is then applied to the super-imposed signals to identify the polarity of the signal detected. The Network Protection Unit can collect all the transient polarity current signals under its protection area. Then The direction of a fault is determined by comparison of the polarity of the signals derived from all the line sections connected to the substation. The actual faulted section is identified by the Network Protection Unit through comparing the directional information from various stations. Simulation results presented in the paper demonstrate the feasibility of the scheme.

Broadband low-frequency sound absorption by periodic metamaterial resonators embedded in a porous layer

Zhu, Xing-Feng,Lau, Siu-Kit,Lu, Zhenbo,Jeon, Wonju Academic Press 2019 Journal of Sound and Vibration Vol.461 No.-

<P><B>Abstract</B></P> <P>Broadband absorption of the audible sound wave at low frequency has been achieved by using periodic acoustic metamaterial resonators (AMRs) embedded inside a porous layer. A single AMR embedded in a porous layer could reach perfect absorption (PA) at the resonance frequency, and it can be easily tuned by adjusting the inner radius of AMR. With four AMRs in the porous layer, a high absorption (>80%) is obtained in the frequency range from 180 Hz to 550 Hz, while the thickness of the porous layer is only 1 / 10 of the relevant wavelength at 300 Hz. The broadband and high absorption performances are due to the interferences of the low-frequency resonances of the AMRs and the energy trapping between the AMRs and the rigid backings. The finite element simulations are experimentally validated. Moreover, the broadband low-frequency absorption is robust under various oblique incidence even at large incident angles. The effects of the acoustic parameters of the porous layer on the absorption properties are also discussed. The absorbers should have high potential for the practical applications in buildings, aircrafts and automobiles due to their ease of fabrication, ultra-thin, and robust high-efficiency.</P>

Analyzing Errors Made by Eighth-Grade Students in Solving Geometrical Problems

( Huang Xing Feng ),( Cheng Long Hai ) 한국수학교육학회 2011 수학교육연구 Vol.15 No.4

In mathematical problem solving, students may make various errors. In order to draw useful lessons from the errors, and then correct them, we surveyed 24 eighth-grade students` performances in geometrical problem solving according to Casey`s hierarchy of errors. It was found that: 1. Students`` effect can lead to errors at the stage of "comprehension", "strategy selection", and "skills manipulation"; and 2. Students`` geometric schemas also influenced their strategy selection".

Association of TNF-α-308 and -238 Polymorphisms with Risk of Cervical Cancer: A Meta-analysis

Pan, Feng,Tian, Jing,Ji, Chu-Shu,He, Yi-Fu,Han, Xing-Hua,Wang, Yong,Du, Jian-Ping,Jiang, Feng-Shou,Zhang, Ying,Pan, Yue-Yin,Hu, Bing Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.11

Published data on the associations between tumor necrosis factor-alpha (TNF-${\alpha}$) promoter -308G>A and -238G>A polymorphisms and cervical cancer risk are inconclusive. To derive a more precise estimation of the relationship, a meta-analysis was performed. Data were collected from MEDLINE and PubMed databases. Crude odds ratios (ORs) with 95% confidence intervals (CIs) were calculated in a fixed/random effect model. 13 separate studies including 3294 cases and 3468 controls were involved in the meta-analysis. We found no association between TNF-${\alpha}$-308G>A polymorphism and cervical cancer in overall population. In subgroup analysis, significantly elevated risks were found in Caucasian population (A vs. G: OR = 1.43, 95% CI = 1.00-2.03; AA vs. GG: OR = 2.09, 95% CI = 1.34-3.25; Recessive model: OR = 2.09, 95% CI = 1.35-3.25) and African population (GA vs. GG: OR = 1.53, 95% CI = 1.02-2.30). An association of TNF-${\alpha}$-238G>A polymorphism with cervical cancer was found (A vs. G: OR = 0.61, 95% CI = 0.47-0.78; GA vs. GG: OR = 0.59, 95% CI = 0.45-0.77; Dominant model: OR = 0.59, 95% CI = 0.46-0.77). When stratified by ethnicity, similar association was observed in Caucasian population (A vs. G: OR = 0.62, 95% CI = 0.46-0.84; GA vs. GG: OR = 0.59, 95% CI = 0.43-0.82; Dominant model: OR = 0.60, 95% CI = 0.44-0.83). In summary, this meta-analysis suggests that TNF-${\alpha}$-238A allele significantly decreased the cervical cancer risk, and the TNF-${\alpha}$-308G>A polymorphism is associated with the susceptibility to cervical cancer in Caucasian and African population.

Effects of SRBSDV-infected rice plants on the fitness of vector and non-vector rice planthoppers

Hong-Xing Xu,Hong-Xing Xu,Xu-Song Zheng,Yajun Yang,Jue-Feng Zhang Zhang,Zhong-Xian Lu 한국응용곤충학회 2016 Journal of Asia-Pacific Entomology Vol.19 No.3

Southern rice black-streaked dwarf virus (SRBSDV) is a new member of the genus Fijivirus and transmitted by whitebacked planthopper (WBPH), Sogatella furcifera (Horváth). The rice area affected by SRBSDV and the subsequent damages are increasing rapidly. In current study, we evaluated the effects of SRBSDV-infected plants on the ecological fitness and the tolerance to adverse environmental factors of vector WBPH and non-vector brown planthopper (BPH), Nilaparvata lugens (Stål). Our study revealed that the fitness of WBPH and BPH were both influenced by feeding on SRBSDV-infected rice. Fecundity ofWBPH feeding on the SRBSDV-infected rice plants were higher than those on healthy plants, nymphal duration of male WBPH prolonged markedly by 0.77 d (P b 0.05), while the weight of brachypterous female adults significantly decreased (P b 0.05), and the average survival time shortened both at 26 °C and 31 °C, respectively. Median lethal time of WBPH on SRBSDV-infected and healthy rice plants were 80 h and 112 h at 26 °C, 64 h and 88 h at 31 °C, respectively. As for non-vector BPH, nymph survival rate decreased significantly by 11.22% (P b 0.05) and the longevity of female adults also shortened (P b 0.05), while hatchability of BPH eggs increased (P b 0.05). Survival time of BPH feeding on healthy rice at 26 °Cwas significant longer than those feeding on healthy and infected rice at 31 °C. The above results imply that the vectorWBPH suffers much stronger effects than non-vector BPH fromfeeding on SRBSDVinfected rice plants.

Dynamic Path Planning Based on Fuzzy and Behavior Control Idea

Lei Yanmin,Xing Xiaoxue,Feng Zhibin,Guan Xiuli,Du Limin 보안공학연구지원센터 2014 International Journal of Control and Automation Vol.7 No.12

In order to solve dynamic path planning problem of multi-robot systems in unknown dynamic environment, a kind of method based on fuzzy and behavior control idea was proposed in this paper. This method designs two fuzzy controllers, which are danger degree fuzzy controller and velocity fuzzy controller. They took fully into account the position and the velocity of the obstacle and the azimuth of the target. Fuzzy rules were designed based on behavior control idea and which reflected move-to-goal behavior, avoid-obstacle behavior and follow-obstacle behavior. The experimental results show that the proposed method is feasible and valid and is suitable for the dynamic and complicated environment in particularly.

An improved radius-incremental-approach of stress and displacement for strain-softening surrounding rock considering hydraulic-mechanical coupling

Zou, Jin-Feng,Wei, Xing-Xing Techno-Press 2018 Geomechanics & engineering Vol.16 No.1

This study focused on the mechanical and hydraulic characteristics of underwater tunnels based on Mohr-Coulomb (M-C), Hoek-Brown (H-B) and generalized H-B failure criteria. An improved approach for calculating stress, displacement and plastic radius of the circular tunnel considering hydraulic-mechanical coupling was developed. The innovation of this study was that the radius-incremental-approach was reconstructed (i.e., the whole plastic zone is divided into a finite number of concentric annuli by radius), stress and displacement of each annulus were determined in terms of numerical method and Terzaghi's effective stress principle. The validation of the proposed approach was conducted by comparing with the results in Brown and Bray (1982) and Park and Kim (2006). In addition, the Rp-pin curve (plastic radius-internal supporting pressure curve) was obtained using the numerical iterative method, and the plastic radius of the deep-buried tunnel could be obtained by interpolation method in terms of the known value of internal supporting pressure pin. Combining with the theories in Carranza and Fairhurst (2000), the improved technique for assessing the reliability of the tunnel support was proposed.