Dynamics of Yeast-like Symbiote and its Relationship with the Virulence of Brown Planthopper, Nilaparvata lugens Stal, to Resistant Rice Varieties

Zhong-Xian Lu,Xiao-Ping Yu,Jian-Ming Chen,Xu-Song Zheng,Hong-Xing Xu,Jue-Feng Zhang Zhang,Lie-Zhong Chen 한국응용곤충학회 2004 Journal of Asia-Pacific Entomology Vol.7 No.3

Abundance of the yeast-like symbiote (YLS) in brown planthopper (BPH), Nilaparvata lugens Stl, collected from rice fields in China and obtained from International Rice Research Institute (IRRI), was monitored. The role of YLS in nymph survival rate, development and adult reproduction, and activities of transaminases in BPH on different resistant rice varieties were examined. Also, the relationship between YLS and virulence shifts of BPH to resistant rice varieties was discussed. The results indicated that the virulence of BPH populations to resistant rice varieties was strongly related to the abundance of YLS in 5th instar nymphs and brachypterous females of BPH field populations at Nanning in South China and Hangzhou in East China, showing the more abundance of YLS in BPH, the higher virulence of BPH to resistant rice varieties, while no obvious differences in YLS abundance were monitored between three BPH biotypes. Numbers of YLS reduced significantly in female adult of BPH biotype 1 fed on resistant rice varieties IR26, Mudgo and ASD7, compared with that fed on susceptible rice variety TN1. The lowest YLS abundance of BPH from field population was found in 2nd generation successively fed on resistant varieties, and the number of YLS was resumed at 4th generation when the BPH has adapted the resistant varieties. The markedly lower nymphal survival rate, adult fecundity and activities of alanine and aspartic transminase, and significantly longer nymph duration in the three aposymbiotic biotypes than in the symbiotic ones were recorded on both susceptible and resistant rice varieties. However, the much greater differences between aposymbiotic and symbiotic BPH were found on the inadaptable resistant rice varieties than that on the fitness resistant rice varieties. Those results implied that YLS in BPH should play a crucial role in the virulent shift of BPH populations to resistant rice varieties.

Dynamics of Yeast-like Symbiote and Its Relationship with the Virulence of Brown Planthopper, Nilaparvata lugens Stal, to Resistant Rice Varieties

Lu, Zhong-Xian,Yu, Xiao-Ping,Chen, Jian-Ming,Zheng, Xu-Song,Xu, Hong-Xing,Zhang, Jue-Feng,Chen, Lie-Zhong Korean Society of Applied Entomology 2004 Journal of Asia-Pacific Entomology Vol.7 No.3

Abundance of the yeast-like symbiote (YLS) in brown planthopper (BPH), Nilaparvata lugens Stal, collected from rice fields in China and obtained from International Rice Research Institute (IRRI), was monitored. The role of YLS in nymph survival rate, development and adult reproduction, and activities of transaminases in BPH on different resistant rice varieties were examined. Also, the relationship between YLS and virulence shifts of BPH to resistant rice varieties was discussed. The results indicated that the virulence of BPH populations to resistant rice varieties was strongly related to the abundance of YLS in 5th instar nymphs and brachypterous females of BPH field populations at Nanning in South China and Hangzhou m East China, showing the more abundance of YLS in BPH, the higher virulence of BPH to resistant rice varieties, while no obvious differences in YLS abundance were monitored between three BPH biotypes. Numbers of YLS reduced significantly in female adult of BPH biotype 1 fed on resistant rice varieties IR26, Mudgo and ASD7, compared with that fed on susceptible rice variety TN1. The lowest YLS abundance of BPH from field population was found in 2nd generation successively fed on resistant varieties, and the number of YLS was resumed at 4th generation when the BPH has adapted the resistant varieties. The markedly lower nymphal survival rate, adult fecundity and activities of alanine and aspartic transminase, and significantly longer nymph duration in the three aposymbiotic biotypes than in the symbiotic ones were recorded on both susceptible and resistant rice varieties. However, the much greater differences between aposymbiotic and symbiotic BPH were found on the inadaptable resistant rice varieties than that on the fitness resistant rice varieties. Those results implied that YLS in BPH should playa crucial role in the virulent shift of BPH populations to resistant rice varieties.

Flexural Behavior of Circular Hollow RC Piers with Reduced Amounts of Inner Hoops

Zhong-Xian Li,Chun-yu Du,Xiao Liang,Bo Zhao 한국콘크리트학회 2020 International Journal of Concrete Structures and M Vol.14 No.2

Reversed cyclic loading tests of two circular hollow RC piers were conducted in this study to investigate the effect of different amounts of inner and outer circular hoops on their flexural behavior. The test results showed that the column with a smaller amount of inner circular hoops presented better flexural response than the as-built column with an equal amount of inner and outer circular hoops. Also, the demand developed on the inner circular hoops was smaller than the outer one within the plastic hinge regions, which verified that using a smaller amount of inner circular hoops was reasonable and effective. By examining the confining stress experienced by the concrete in the radial and circumferential directions based on a detailed theoretical analysis, a modeling approach was proposed to take the confinement effect in circular hollow RC piers into consideration. The proposed modeling approach was validated through comparisons with the experimental study and satisfactory agreement was found.

Effects of Plant Nitrogen on Ecological Fitness of the Brown Planthopper, Nilaparvata lugens Stal. in Rice

Lu, Zhong-Xian,Heong, Kong-Luen,Yu, Xiao-Ping,Cui Hu Korean Society of Applied Entomology 2004 Journal of Asia-Pacific Entomology Vol.7 No.1

Ecological fitness characters of the brown planthopper increased proportionally with increase in nitrogen content of rice plants they were bred on. The nymphs survived better and had shorter life spans. Females weighed heavier, laid more eggs and lived longer. In addition, egg hatchability was significantly increased. Number of insects and dry mass from one pair of parents were also significantly higher in high nitrogen plants. Relationships between each of these characters with nitrogen content fitted the linear models well. These characters from insects reared on four successive generations in low, medium and high nitrogen regimes were also investigated. There was little between-generation difference in most characters, except for the population and its dry mass produced by one pairs of insects. This implies that in areas where nitrogen-rich crops are abundant over long periods, ecological fitness of the brown planthoppers are potentially higher and if natural biological control is compromised, the risk of extensive outbreaks are higher. Implications to sudden stoppage of insecticide use in these areas are also discussed.

Effect of sintering temperature on properties of lightweightporous ceramics prepared by foam impregnation method

Zhili Cui,Shiming Xiao,Xianli Luo,Yunxuan Liu,Ming Liu,Yuyun Zeng,Xiaoli Zhong,Hong Zheng,Haifeng Guo 한양대학교 청정에너지연구소 2023 Journal of Ceramic Processing Research Vol.24 No.5

In this paper, cheap mineral materials were used as the base materials of lightweight porous ceramics prepared through foamimpregnation method. The effect of the sintering temperature on the properties of the prepared porous ceramics was studied. The porous ceramic was mainly composed of amorphous silicon oxide, crystalline cordierite and mullite phases, and a smallamount of alumina phase. As the sintering temperature increased, the porosity of porous ceramics gradually decreased from94% to 92%, and the bulk density increased from 0.173 gcm-3 at 1100 ℃ to 0.194 gcm-3 at 1200 ℃. The best sinteringtemperature was 1180 ℃. The porosity of the porous ceramics sintered at 1180 ℃ was 92.14%, the volume weight was 0.189gcm-3, the shrinkage rate was 15.80%, the compressive strength was 0.79 MPa, and the thermal conductivity was 0.295 Wm-1k-1. The lightweight porous ceramic has high porosity, low density and good thermal insulation, as well as low cost, having greatpotential for application in fields such as thermal insulation, adsorption, and environmental protection.

Ischemic postconditioning protects cardiomyocytes against ischemia/reperfusion injury by inducing MIP2

Zhu, Hong-Lin,Wei, Xing,Qu, Shun-Lin,Zhang, Chi,Zuo, Xiao-Xia,Feng, Yan-Sheng,Luo, Qi,Chen, Guang-Wen,Liu, Mei-Dong,Jiang, Lei,Xiao, Xian-Zhong,Wang, Kang-Kai Korean Society for Biochemistry and Molecular Bion 2011 Experimental and molecular medicine Vol.43 No.8

Cardiomyocytes can resist ischemia/reperfusion(I/R) injury through ischemic postconditioning (IPoC) which is repetitive ischemia induced during the onset of reperfusion. Myocardial ischemic preconditioning up-regulated protein 2 (MIP2) is a member of the WD-40 family proteins, we previously showed that MIP2 was up-regulated during ischemic preconditioning (IPC). As IPC and IPoC engaged similar molecular mechanisms in cardioprotection, this study aimed to elucidate whether MIP2 was up-regulated during IPoC and contributed to IPoC-mediated protection against I/R injury. The experiment was conducted on two models, an $in$ $vivo$ open chest rat coronary artery occlusion model and an $in$ $vitro$ model with H9c2 myogenic cells. In both models, 3 groups were constituted and randomly designated as the sham, I/R and IPoC/hypoxia postconditioning (HPoC) groups. In the IPoC group, after 45 min of ischemia, hearts were allowed three cycles of reperfusion/ischemia phases (each of 30 s duration) followed by reperfusion. In the HPoC group, after 6 h of hypoxia, H9c2 cells were subjected to three cycles of 10 minute reoxygenation and 10 minute hypoxia followed by reoxygenation. IPoC significantly reduced the infarct size, plasma level of Lactate dehydrogenase and creatine kinase MB in rats. 12 h after the reperfusion, MIP2 mRNA levels in the IPoC group were 10 folds that of the sham group and 1.4 folds that of the I/R group. Increased expression of MIP2 mRNA and attenuation of apoptosis were similarly observed in the HPoC group in the $in$ $vitro$ model. These effects were blunted by transfection with MIP2 siRNA in the H9c2 cells. This study demonstrated that IPoC induced protection was associated with increased expression of MIP2. Both MIP2 overexpression and MIP2 suppression can influence the IPoC induced protection.

Analytical and Numerical Studies on Steel Columns with Novel Connections in Modular Construction

En-Feng Deng,Jia-Bao Yan,Yang Ding,Liang Zong,Zhong-Xian Li,Xiao-Meng Dai 한국강구조학회 2017 International Journal of Steel Structures Vol.17 No.4

modular construction is a new type of promising structures. This type of structure is an excellent alternative to conventional on-site buildings with advantages of shortened construction time, improved construction quality and reduced environmental pollution. A new concept of modular construction with novel connections has been proposed. This paper mainly focuses on the behavior and design of the innovative steel column working together with tenons at both ends. The fourthdifferential equation was firstly adopted to develop a theoretical model to determine the buckling length of the column. Then, a 3-D nonlinear finite element (FE) model was developed to simulate the ultimate strength behavior of the novel column under pure compression. Parametric studies reveal that the tenons play a significant role in affecting the ultimate load and the corresponding end shortening, among which the length of the tenons is the most important factor. The design approach and recommendations are also discussed through assessing the applicability of the current design code.

Ischemic postconditioning protects cardiomyocytes against ischemia/reperfusion injury by inducing MIP2

Hong-Lin Zhu,Kang-Kai Wang,Xing Wei,Shun-Lin Qu,Chi Zhang,Xiao-Xia Zuo,Yan-Sheng Feng,Qi Luo,Guang-Wen Chen,Mei-Dong Liu,Lei Jiang,Xian-Zhong Xiao 생화학분자생물학회 2011 Experimental and molecular medicine Vol.43 No.8

Cardiomyocytes can resist ischemia/reperfusion (I/R)injury through ischemic postconditioning (IPoC)which is repetitive ischemia induced during the onset of reperfusion. Myocardial ischemic preconditioning up-regulated protein 2 (MIP2) is a member of the WD-40family proteins, we previously showed that MIP2 was up-regulated during ischemic preconditioning (IPC). As IPC and IPoC engaged similar molecular mechanisms in cardioprotection, this study aimed to elucidate whether MIP2 was up-regulated during IPoC and contributed to IPoC-mediated protection against I/R injury. The experiment was conducted on two models,an in vivo open chest rat coronary artery occlusion model and an in vitro model with H9c2 myogenic cells. In both models, 3 groups were constituted and randomly designated as the sham, I/R and IPoC/hypoxia postconditioning (HPoC) groups. In the IPoC group, after 45 min of ischemia, hearts were allowed three cycles of reperfusion/ischemia phases (each of 30 s duration)followed by reperfusion. In the HPoC group, after 6 h of hypoxia, H9c2 cells were subjected to three cycles of 10 minute reoxygenation and 10 minute hypoxia followed by reoxygenation. IPoC significantly reduced the infarct size, plasma level of Lactate dehydrogenase and creatine kinase MB in rats. 12 h after the reperfusion,MIP2 mRNA levels in the IPoC group were 10 folds that of the sham group and 1.4 folds that of the I/R group. Increased expression of MIP2 mRNA and attenuation of apoptosis were similarly observed in the HPoC group in the in vitro model. These effects were blunted by transfection with MIP2 siRNA in the H9c2cells. This study demonstrated that IPoC induced protection was associated with increased expression of MIP2. Both MIP2 overexpression and MIP2 suppression can influence the IPoC induced protection.