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Search Results: 1 - 10 of 16816 matches for " Juming Zhong "
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A Review on High-Dimensional Frequentist Model Averaging  [PDF]
Peipei Fu, Juming Pan
Open Journal of Statistics (OJS) , 2018, DOI: 10.4236/ojs.2018.83033
Abstract: Model averaging has attracted increasing attention in recent years for the analysis of high-dimensional data. By weighting several competing statistical models suitably, model averaging attempts to achieve stable and improved prediction. To obtain a better understanding of the available model averaging methods, their properties and the relationships between them, this paper is devoted to make a review on some recent progresses in high-dimensional model averaging from the frequentist perspective. Some future research topics are also discussed.
Marginal Conceptual Predictive Statistic for Mixed Model Selection  [PDF]
Cheng Wenren, Junfeng Shang, Juming Pan
Open Journal of Statistics (OJS) , 2016, DOI: 10.4236/ojs.2016.62021
Abstract: We focus on the development of model selection criteria in linear mixed models. In particular, we propose the model selection criteria following the Mallows’ Conceptual Predictive Statistic (Cp) [1] [2] in linear mixed models. When correlation exists between the observations in data, the normal Gauss discrepancy in univariate case is not appropriate to measure the distance between the true model and a candidate model. Instead, we define a marginal Gauss discrepancy which takes the correlation into account in the mixed models. The model selection criterion, marginal Cp, called MCp, serves as an asymptotically unbiased estimator of the expected marginal Gauss discrepancy. An improvement of MCp, called IMCp, is then derived and proved to be a more accurate estimator of the expected marginal Gauss discrepancy than MCp. The performance of the proposed criteria is investigated in a simulation study. The simulation results show that in small samples, the proposed criteria outperform the Akaike Information Criteria (AIC) [3] [4] and Bayesian Information Criterion (BIC) [5] in selecting the correct model; in large samples, their performance is competitive. Further, the proposed criteria perform significantly better for highly correlated response data than for weakly correlated data.
Cloning and Polymorphisms of Yak Lactate Dehydrogenase b Gene
Guosheng Wang,Xingbo Zhao,Juming Zhong,Meng Cao,Qinghua He,Zhengxin Liu,Yaqiu Lin,Yaou Xu,Yucai Zheng
International Journal of Molecular Sciences , 2013, DOI: 10.3390/ijms140611994
Abstract: The main objective of this work was to study the unique polymorphisms of the lactate dehydrogenase-1 (LDH1) gene in yak ( Bos grunniens). Native polyacrylamide gel electrophoresis revealed three phenotypes of LDH1 (a tetramer of H subunit) in yak heart and longissimus muscle extracts. The corresponding gene, ldhb, encoding H subunits of three LDH1 phenotypes was obtained by RT-PCR. A total of six nucleotide differences were detected in yak ldhb compared with that of cattle, of which five mutations cause amino acid substitutions. Sequence analysis shows that the G896A and C689A, mutations of ldhb gene, result in alterations of differently charged amino acids, and create the three phenotypes (F, M, and S) of yak LDH1. Molecular modeling of the H subunit of LDH indicates that the substituted amino acids are not located within NAD + or substrate binding sites. PCR-RFLP examination of G896A mutation demonstrated that most LDH1-F samples are actually heterozygote at this site. These results help to elucidate the molecular basis and genetic characteristic of the three unique LDH1 phenotypes in yak.
Nonlinear disturbance attenuation control for four-leg active power filter based on voltage source inverter

Juming CHEN,Feng LIU,Shengwei MEI,

控制理论与应用 , 2006,
Abstract: Active power filter (APF) based on voltage source inverter VSI is one of the important measures for handling the power quality problem. Mathematically, the APF model in a power grid is a typical nonlinear one. The idea of passivity is a powerful tool to study the stabilization of such a nonlinear system. In this paper, a state-space model of the four-leg APF is derived, based on which a new H-infinity controller for current tracking is proposed from the passivity point of view. It can achieve not only asymptotic tracking, but also disturbance attenuation in the sense of L2-gain. Subsequently, a sufficient condition to guarantee the boundedness and desired mean of the DC voltage is also given. This straightforward condition is consistent with the power-balancing law of electrical circuits. Simulations performed on PSCAD platform verify the validity of the new approach.
Infrared carpet cloak designed with uniform silicon grating structure
Xiaofei Xu,Yijun Feng,Yu Hao,Juming Zhao,Tian Jiang
Physics , 2009, DOI: 10.1063/1.3259775
Abstract: Through a particularly chosen coordinate transformation, we propose an optical carpet cloak that only requires homogeneous anisotropic dielectric material. The proposed cloak could be easily imitated and realized by alternative layers of isotropic dielectrics. To demonstrate the cloaking performance, we have designed a two-dimensional version that a uniform silicon grating structure fabricated on a silicon-on-insulator wafer could work as an infrared carpet cloak. The cloak has been validated through full wave electromagnetic simulations, and the non-resonance feature also enables a broadband cloaking for wavelengths ranging from 1372 to 2000 nm.
Switchable metamaterial reflector/absorber for different polarized electromagnetic waves
Bo Zhu,Yijun Feng,Juming Zhao,Ci Huang,Tian Jiang
Physics , 2010, DOI: 10.1063/1.3477960
Abstract: We demonstrate a controllable electromagnetic wave reflector/absorber for different polarizations with metamaterial involving electromagnetic resonant structures coupled with diodes. Through biasing at different voltages to turn ON and OFF the diodes, we are able to switch the structure between nearly total reflection and total absorption of a particularly polarized incident wave. By arranging orthogonally orientated resonant cells, the metamaterial can react to different polarized waves by selectively biasing the corresponding diodes. Both numerical simulations and microwave measurements have verified the performance.
A Built-In Strategy for Containment of Transgenic Plants: Creation of Selectively Terminable Transgenic Rice
Chaoyang Lin, Jun Fang, Xiaoli Xu, Te Zhao, Jiaan Cheng, Juming Tu, Gongyin Ye, Zhicheng Shen
PLOS ONE , 2008, DOI: 10.1371/journal.pone.0001818
Abstract: Plant transgenic technology has been widely utilized for engineering crops for trait improvements and for production of high value proteins such as pharmaceuticals. However, the unintended spreading of commercial transgenic crops by pollination and seed dispersal is a major concern for environmental and food safety. Simple and reliable containment strategies for transgenes are highly desirable. Here we report a novel method for creating selectively terminable transgenic rice. In this method, the gene(s) of interest is tagged with a RNA interference cassette, which specifically suppresses the expression of the bentazon detoxification enzyme CYP81A6 and thus renders transgenic rice to be sensitive to bentazon, a herbicide used for rice weed control. We generated transgenic rice plants by this method using a new glyphosate resistant 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) gene from Pesudomonas putida as the gene of interest, and demonstrated that these transgenic rice plants were highly sensitive to bentazon but tolerant to glyphosate, which is exactly the opposite of conventional rice. Field trial of these transgenic rice plants further confirmed that they can be selectively killed at 100% by one spray of bentazon at a regular dose used for conventional rice weed control. Furthermore, we found that the terminable transgenic rice created in this study shows no difference in growth, development and yield compared to its non-transgenic control. Therefore, this method of creating transgenic rice constitutes a novel strategy of transgene containment, which appears simple, reliable and inexpensive for implementation.
The Role of Peroxisome Proliferator-Activated Receptor and Effects of Its Agonist, Pioglitazone, on a Rat Model of Optic Nerve Crush: PPARγ in Retinal Neuroprotection
Juming Zhu, Junfang Zhang, Min Ji, Hongwei Gu, Yue Xu, Chen Chen, Nan Hu
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0068935
Abstract: It has been shown that peroxisome proliferators-activated receptor gamma (PPARγ) is beneficial for central nervous system injury. However its role on optic nerve injury remains unknown. In the present study, we examined the change of PPARγ expression in rat retina following optic nerve injury and investigated the effect of pioglitazone (Pio), a PPARγ agonist, on retinal ganglion cells (RGCs) neuroprotection using a rat optic nerve crush (ONC) model. Our results showed that PPARγ mRNA and protein levels were increased after ONC, and most of PPARγ-immunoreactive cells colocalized with Müller cells. Pio treatment significantly enhanced the number of surviving RGCs and inhibited RGCs apoptosis induced by ONC. However, when PPARγ antagonist GW9662 was used, these neuroprotective effects were abolished. In addition, pio attenuated Müller cell activation after ONC. These results indicate that PPARγ appears to protect RGCs from ONC possibly via the reduction of Müller glial activation. It provides evidence that activation of PPARγ may be a potential alternative treatment for RGCs neuroprotection.
Trichothecin Induces Cell Death in NF-κB Constitutively Activated Human Cancer Cells via Inhibition of IKKβ Phosphorylation
Jia Su, Peiji Zhao, Lingmei Kong, Xingyao Li, Juming Yan, Ying Zeng, Yan Li
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0071333
Abstract: Constitutive activation of the transcription factor nuclear factor-κB (NF-κB) is involved in tumorigenesis and chemo-resistance. As the key regulator of NF-κB, IKKβ is a major therapeutic target for various cancers. Trichothecin (TCN) is a metabolite isolated from an endophytic fungus of the herbal plant Maytenus hookeri Loes. In this study, we evaluated the anti-tumor activity of TCN and found that TCN markedly inhibits the growth of cancer cells with constitutively activated NF-κB. TCN induces G0/G1 cell cycle arrest and apoptosis in cancer cells, activating pro-apoptotic proteins, including caspase-3, -8 and PARP-1, and decreasing the expression of anti-apoptotic proteins Bcl-2, Bcl-xL, and survivin. Reporter activity assay and target genes expression analysis illustrated that TCN works as a potent inhibitor of the NF-κB signaling pathway. TCN inhibits the phosphorylation and degradation of IκBα and blocks the nuclear translocation of p65, and thus inhibits the expression of NF-κB target genes XIAP, cyclin D1, and Bcl-xL. Though TCN does not directly interfere with IKKβ kinase, it suppresses the phosphorylation of IKKβ. Overexpression of constitutively activated IKKβ aborted TCN induced cancer cell apoptosis, whereas knockdown of endogenous IKKβ with siRNA sensitized cancer cells toward apoptosis induced by TCN. Moreover, TCN showed a markedly weaker effect on normal cells. These findings suggest that TCN may be a potential therapeutic candidate for cancer treatment, targeting NF-κB signaling.
Effects of antioxidants on homocysteine thiolactone-induced apoptosis in human umbilical vein endothelial cells
Weijun GU,Juming LU,Guoqing YANG,Qinghua GUO,Baoan WANG,Yiming MU,Changyu PAN,
Weijun GU
,Juming LU,Guoqing YANG,Qinghua GUO,Baoan WANG,Yiming MU,Changyu PAN

老年心脏病学杂志(英文版) , 2006,
Abstract: Background and objectives Hyperhomocysteinemia is an independent risk factor for cardiovascular disease. Homocysteine thiolactone (HcyT), one of the homocysteine metabolites in vivo, is toxic both in vivo and in vitro. The aim of this study was to investigate the effect of HcyT on apoptotic damage in human umbilical vein endothelial cells (HUVECs) and the role of antioxidants in the reduction of HcyT-induced apoptosis. Methods HUVECs were cultured in DMEM supplemented with 20% heat inactivated fetal bovine serum cell cultures were maintained in a humidified 5% CO, atmosphere at 37°C. Cytotoxicity was determined by MTT assay, which consists of hypodiploid cells with propidium iodide labeling and intracellular reactive oxygen species levels using 2',7'-dichlorofluorescein diacetate as the probe by flow cytometry. Results HcyT (250-2000uM) induced HUVECs apoptosis in a time- and concentration-dependent manner. Reactive oxygen species levels rose in response to increasing HcyT concentrations at 24-h incubation. The reduction of cell apoptosis by N-acetylcysteine, vitamin E, or pyrrolidine dithiocarbamate, occurred simultaneously with a signifi-cant decrease in intracellular reactive oxygen species levels. Conclusion HcyT exerts its cytotoxic effects on endothelial cells through an apoptotic mechanism involving cellular reactive oxygen species production. The capacity of N-acetylcysteine, vitamin E, and pyrrolidine dithiocarbamate to scavenge HcyT-induced cellular reactive oxygen species correlates well with their efficiency to protect against HcyT-promoted apoptotic damage. The protective effect of pyrrolidine dithiocarbamate on cell apoptosis indicates HcyT-generated hydrogen peroxide may provoke cell apoptosis via activating nuclear factor-kappa binding protein.
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