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Search Results: 1 - 10 of 96419 matches for " Han Liu "
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Integral Inequalities of Hermite-Hadamard Type for r-Convex Functions  [PDF]
Lingxiong Han, Guofeng Liu
Applied Mathematics (AM) , 2012, DOI: 10.4236/am.2012.312270
Abstract: The main aim of this present note is to establish three new Hermite-Hadamard type integral inequalities for r-convex functions. The three new Hermite-Hadamard type integral inequalities for r-convex functions improve the result of original one by H?lder’s integral inequality, Stolarsky mean and convexity of function.
The Evolution of Microtubule End-Binding Protein 1 (EB1) and Roles in Regulating Microtubule Behavior  [PDF]
Jiayu Liu, Rong Han
American Journal of Plant Sciences (AJPS) , 2015, DOI: 10.4236/ajps.2015.613212
Abstract: All organisms must transmit genetic information to offspring through cell division, and mitotic spindle participates in the process. Spindle dynamics through depolymerization or polymerization of microtubules generates the driving force required for chromosome movements in mitosis. To date, studies have shown that microtubule arrays control the directions of cell division and diverse microtubule-associated proteins regulate cell division. But a clear picture of how microtubules and microtubule-associated proteins modulate cell division remains unknown. Depletion of end-binding protein 1 by RNA-mediated inhibition shows that one of the microtubule-associated proteins, end-binding protein 1, plays a crucial role in mitotic spindle formation and promotes microtubule dynamics and is needed for the proper segregation of mitotic chromosomes during anaphase in Drosophila cells. Here, we review the properties of end-binding protein 1 and the roles of end-binding protein 1 in regulating microtubule behavior and in cell cycle.
High Dimensional Semiparametric Scale-Invariant Principal Component Analysis
Fang Han,Han Liu
Statistics , 2014,
Abstract: We propose a new high dimensional semiparametric principal component analysis (PCA) method, named Copula Component Analysis (COCA). The semiparametric model assumes that, after unspecified marginally monotone transformations, the distributions are multivariate Gaussian. COCA improves upon PCA and sparse PCA in three aspects: (i) It is robust to modeling assumptions; (ii) It is robust to outliers and data contamination; (iii) It is scale-invariant and yields more interpretable results. We prove that the COCA estimators obtain fast estimation rates and are feature selection consistent when the dimension is nearly exponentially large relative to the sample size. Careful experiments confirm that COCA outperforms sparse PCA on both synthetic and real-world datasets.
Optimal Rates of Convergence for Latent Generalized Correlation Matrix Estimation in Transelliptical Distribution
Fang Han,Han Liu
Statistics , 2013,
Abstract: Correlation matrix plays a key role in many multivariate methods (e.g., graphical model estimation and factor analysis). The current state-of-the-art in estimating large correlation matrices focuses on the use of Pearson's sample correlation matrix. Although Pearson's sample correlation matrix enjoys various good properties under Gaussian models, its not an effective estimator when facing heavy-tail distributions with possible outliers. As a robust alternative, \cite{han2012transelliptical} advocated the use of a transformed version of the Kendall's tau sample correlation matrix in estimating high dimensional latent generalized correlation matrix under the transelliptical distribution family (or elliptical copula). The transelliptical family assumes that after unspecified marginal monotone transformations, the data follow an elliptical distribution. In this paper, we study the theoretical properties of the Kendall's tau sample correlation matrix and its transformed version proposed in \cite{han2012transelliptical} for estimating the population Kendall's tau correlation matrix and the latent Pearson's correlation matrix under both spectral and restricted spectral norms. With regard to the spectral norm, we highlight the role of "effective rank" in quantifying the rate of convergence. With regard to the restricted spectral norm, we for the first time present a "sign subgaussian condition" which is sufficient to guarantee that the rank-based correlation matrix estimator attains the optimal rate of convergence. In both cases, we do not need any moment condition.
ECA: High Dimensional Elliptical Component Analysis in non-Gaussian Distributions
Fang Han,Han Liu
Statistics , 2013,
Abstract: We propose a robust alternative to principal component analysis (PCA) -- named elliptical component analysis (ECA) -- for analyzing high dimensional elliptically distributed data. ECA aims at estimating the eigenspace of the covariance matrix of the elliptical data. To cope with the heavy-tailed elliptical distributions, a multivariate rank statistic is exploited. At the model-level, we consider two settings that the leading eigenvectors of the covariance matrix are non-sparse or sparse. Methodologically, we propose ECA procedures corresponding to both non-sparse and sparse settings. Theoretically, we provide both non-asymptotic and asymptotic analysis in quantifying the theoretical performances of ECA. Under the non-sparse setting, we show that ECA's performance is highly related to the effective rank of the covariance matrix. Under the sparse setting, the results are in two folds: (i) We show that the sparse ECA estimator based on a combinatoric program attains the optimal rate of convergence; (ii) Built upon some recent developments in estimating sparse leading eigenvectors, we show that a computationally efficient sparse ECA estimator attains the optimal rate of convergence under a suboptimal scaling.
Distribution-Free Tests of Independence with Applications to Testing More Structures
Fang Han,Han Liu
Statistics , 2014,
Abstract: We consider the problem of testing mutual independence of all entries in a d-dimensional random vector X=(X_1,...,X_d)^T based on n independent observations. For this, we consider two families of distribution-free test statistics that converge weakly to an extreme value type I distribution. We further study the powers of the corresponding tests against certain alternatives. In particular, we show that the powers tend to one when the maximum magnitude of the pairwise Pearson's correlation coefficients is larger than C(log d/n)^{1/2} for some absolute constant C. This result is rate optimal. As important examples, we show that the tests based on Kendall's tau and Spearman's rho are rate optimal tests of independence. For further generalization, we consider accelerating the rate of convergence via approximating the exact distributions of the test statistics. We also study the tests of two more structural hypotheses: m-dependence and data homogeneity. For these, we propose two rank-based tests and show their optimality.
Transverse Single Spin Asymmetry Measurement with J/Psi in Polarized p+p Collisions at RHIC
Han Liu
Physics , 2006, DOI: 10.1063/1.2750841
Abstract: The PHENIX experiment has measured transverse single spin asymmetry of J/$\Psi$ in polarized p+p collisions at forward rapidity at $\sqrt{s}=200$ GeV. The data were collected from year 2006 run of RHIC with average beam polarization of 56%. At RHIC energy, heavy quark production is dominated by gluon gluon interaction. Therefore, the transverse single spin asymmetry in J/$\Psi$ production can provide a clean measurement of the gluon Sivers distribution function.
Chronic eosinophilic pneumonia: A case report and review of the literature  [PDF]
Yunjie Ge, Xiudi Han, Xuedong Liu
Open Journal of Internal Medicine (OJIM) , 2013, DOI: 10.4236/ojim.2013.34027
Abstract:

Objective: We introduce one case of chronic eosinophilic pneumonia (CEP) and review the literature nearly 10 years in order to improve the understanding of this rare disease. Methods: A case of CEP diagnosed by transbronchial lung biopsy with clinical and follow-up data was analyzed and its clinical features, diagnosis and treatment combined with the literature were discussed. Result: CEP is a chronic pulmonary eosinophilic inflammation with unknown etiology, characterized by history of allergic disease, cough, sputum, but often breathlessness and wheezing; eosinophil in peripheral blood and/or sputum and/or bronchoalveolar lavage fluid significantly increased; chest X-ray showed progressively peripheral non-segment distribution of high-density infiltrates, often called “reversed pulmonary edema sign”; Pathology showed eosinophil infiltration in lung interstitial, bronchial submucosal and excessive eosinophil exudation in alveolar. Oral corticosteroids had a good response, but easy to relapse. Conclusions: Eosinophil count of bronchoalveolar lavage or lung biopsy can confirm the diagnosis of CEP timely in suspected patients. Bronchoscope can play an important role in assisting diagnosis and improving symptoms. 

The Effects of He-Ne Laser and Enhanced Ultraviolet-B Radiation on Proliferating-Cell Nuclear Antigen in Wheat Seedlings  [PDF]
Feifeng Liu, Huize Chen, Rong Han
American Journal of Plant Sciences (AJPS) , 2015, DOI: 10.4236/ajps.2015.68124
Abstract: The level of ultraviolet-B (UV-B) radiation on the Earth’s surface has increased due to depletion of the ozone layer. Here, we explored the effects of continuous wave He-Ne laser irradiation (632 nm, 5 mW·mm-2, 2 min·d-1) on proliferating-cell nuclear antigen (PCNA) damage repair function of wheat seedlings exposed to enhanced UV-B radiation (10.08 kJ·m-2·d-1) at the early growth stages. Wheat seedlings were irradiated with enhanced UV-B, He-Ne laser treatment or a combination of the two. We explored the transcripts of PCNA in each treatment group using RT-PCR. In addition, total proteins were extracted from the 7-day-old wheat leaves, analyzed by SDS-PAGE and identified by western blot. The results showed that the transcription of PCNA was weakened following UV-B radiation compared to the control. However, when seedlings were subjected to elevated UV-B-damaging radiation followed by He-Ne laser irradiation, the expression of PCNA was signifi-cantly higher than UV-B radiation alone. These results suggest that He-Ne laser has an active role in repairing the UV-B damaging effects. In order to further investigate the function of PCNA, dynamic arrangements of PCNA in wheat root-tip cells were observed with confocal laser scanning microscopy (CLSM). The PCNA was marked fluorescent dimming and strength weakened in en-hanced UV-B radiation (UV-B) compared with the control group (CK) during processing. It shows that PCNA may be involved in the separation of chromosomes.
Different Doses of the Enhanced UV-B Radiation Effects on Wheat Somatic Cell Division  [PDF]
Feifeng Liu, Huize Chen, Rong Han
CellBio (CellBio) , 2015, DOI: 10.4236/cellbio.2015.42004
Abstract: Being sessile, plants are continuously exposed to DNA-damaging agents presenting in the environment such as ultraviolet (UV). Sunlight acts as an energy source for photosynthetic plants; hence, avoidance of UV radiations (namely, UV-A, 315 - 400 nm; UV-B, 280 - 315 nm; and UV-C, <280 nm) is unpreventable. DNA in particular strongly absorbs UV-B; therefore, it is the most important target for UV-B induced damages. This paper mainly used different doses of the enhanced UV-B radiation (B1 group: 4.05 kJ•m-2•d-1, B2 group: 10.08 kJ•m-2•d-1, B3 group: 7.05 kJ•m-2•d-1, B4 group: 23.02 kJ•m-2•d-1) treatment wheat, then, explored on the growth of wheat root and wheat root tip cell of chromosome aberration effect. In wheat, root-tip cells were observed with confocal laser scanning microscopy (CLSM), the results showed that low doses of B1 group (4.05 kJ•m-2•d-1) promoted the growth of wheat root and cell mitosis frequency. But high dose of B2 group (10.08 kJ•m-2•d-1), B3 group (17.05 kJ•m-2•d-1), B4 group (23.02 kJ•m-2•d-1) inhibited the growth of wheat root tip, and made crooked growth of wheat root, and inhibited the wheat root tip cell mitotic frequency and processed that induce root tip cells of wheat produce all kinds of aberration of chromosome in the interphase containing “multiple nucleoli nuclei”, “incomplete nuclei”, “long round nuclei”, “bean sprouts nucleus”. In mitosis M period contains “dissociative chromosome”, “chromosome bridge”, “adhesion chromosome”, “multi-bundle divide”, “nuclear anomalies”. After, high doses of enhanced UV-B radiation treatment, most of the cell cycle anomaly concentrated in mitosis interphase. In mitosis M period, with UV-B radiation dose enhanced chromosome aberration rate was on the rise and the aberration types also increasing.
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