Wang W.,Zhejiang University |
Wang W.,Liaocheng University |
Qian Y.,Zhejiang University
IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing | Year: 2015
Hyperspectral unmixing is an important step for material classification and recognition. Recently, nonnegative matrix factorization (NMF) has been utilized to unmix the hyperspectal imagery due to the advantage that it needs no assumption for the presence of pure pixels and can determine the endmembers and abundances simultaneously. In order to improve its unmixing performance, sparsity-constrained NMF has been demonstrated to be an efficient approach. The very recent study on L1/2 regularization theory in compressive sensing (CS) and sparsity-constrained NMF show that the L1/2 regularizer can yield stronger sparsity-promoting solutions than L1 or L2 regularizer. However, the L1/2 regularization can result in a complex nonconvex optimization problem that is hard to solve efficiently. In this paper, we propose a fast and efficient adaptive half-thresholding algorithm for hyperspectral unmixing based on L1/2 sparsity-constrained NMF. In the proposed algorithm, iterative half-thresholding procedure that has been proved to be an efficient method for solving L1/2 regularization problem in CS is hybridized with the multiplicative update rule of standard NMF to deal with the L1/2 sparsity-constrained NMF, which can give sparser and better unmixing results than the alternative algorithms. Furthermore, the data sparsity information can be incorporated into the algorithm to adaptively adjust the regularization parameter of the model to improve algorithm performance and usability. The effectiveness of proposed algorithm was demonstrated by comparing with the representative algorithms on synthetic and real hyperspectral data. © 2008-2012 IEEE.
Liu Z.,Nanjing University |
Liu Z.,Liaocheng University |
He W.,Nanjing University |
Guo Z.,Nanjing University
Chemical Society Reviews | Year: 2013
Coordination chemistry plays an essential role in the design of photoluminescent probes for metal ions. Metal coordination to organic dyes induces distinct optical responses which signal the presence of metal species of interest. Luminescent lanthanide (Ln3+) and transition metal complexes of d6, d8 and d10 configurations often exhibit unique luminescence properties different from organic dyes, such as high quantum yield, large Stokes shift, long emission wavelength and emission lifetimes, low sensitivity to microenvironments, and can be explored as lumophores to construct probes for metal ions, anions and neutral species. In this review, the design principles and coordination chemistry of metal probes based on mechanisms of PeT, PCT, ESIPT, FRET, and excimer formation will be discussed in detail. Particular attention will be given to rationales for the design of turn-on and ratiometric probes. Moreover, phosphorescent probe design based on Ln3+ and d6, d8 and d 10-metal complexes are also presented via discussing certain factors affecting the phosphorescence of these metal complexes. A survey of the latest progress in photoluminescent probes for identification of essential metal cations in the human body or toxic metal cations in the environment will be presented focusing on their design rationales and sensing behaviors. Metal complex-based photoluminescent probes for biorelated anions such as PPi, and neutral biomolecules ATP, NO, and H2S will be discussed also in the context of their metal coordination-related sensing behaviors and design approaches. © 2013 The Royal Society of Chemistry.
Yang Z.,Liaocheng University
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2013
We study the physical mechanism and the information velocity of fast light based on the time-domain propagator governing light propagation in a dispersive system. We show that the output pulse can be regarded as the superposition of multiple "copies" of the input pulse, each traveling at a well-defined signal velocity no greater than the speed of light in vacuum, and the interference between the front edges of these copies generates the peak of the output pulse. The information velocity is defined as the ratio of the propagation distance to the mini-mum time required to complete any given information transfer process, directly reflecting how fast the signal of interest, i.e., the part of the pulse that carries the information of interest, propagates. With the peak of the output pulse representing the information, as is typical in slow- and fast-light applications, we find that the information velocity is significantly smaller than the speed of a discontinuity in the pulse, which was traditionally proposed to be the signal velocity of fast light. The analysis can also be applied to slow-light propagation. © 2013 American Physical Society.
Yao Y.,University of Regina |
Yao B.,Liaocheng University
Information Sciences | Year: 2012
We propose a framework for the study of covering based rough set approximations. Three equivalent formulations of the classical rough sets are examined by using equivalence relations, partitions, and σ-algebras, respectively. They suggest the element based, the granule based and the subsystem based definitions of approximation operators. Covering based rough sets are systematically investigated by generalizing these formulations and definitions. A covering of universe of objects is used to generate different neighborhood operators, neighborhood systems, coverings, and subsystems of the power set of the universe. They are in turn used to define different types of generalized approximation operators. Within the proposed framework, we review and discuss covering based approximation operators according to the element, granule, and subsystem based definitions. © 2012 Elsevier Inc. All rights reserved.
Zhao Z.-J.,Liaocheng University
Journal of Experimental Biology | Year: 2011
The combination of two stressors, lactation and cold, is suggested to be an excellent model for testing the factors limiting sustained energy intake (SusEI). Limits to SusEI during peak lactation may be imposed peripherally by the capacity of mammary glands to produce milk or may be driven by the ability of animals to dissipate body heat. To distinguish between the two mechanisms, body mass change, food intake, reproductive output (using litter size and mass) and serum prolactin (PRL) levels were measured in striped hamsters lactating at 23, 30 and 5°C. Resting metabolic rate (RMR) during late lactation was also measured. Female hamsters lactating at 5°C showed significantly lower change in body mass, but had higher food intake and RMR than females at 23 and 30°C. Asymptotic food intake averaged 14.6±0.4, 14.5±0.7 and 16.2±0.5 g d-1 for females at 23, 30 and 5°C, respectively. The females at 5°C had 11.4% higher asymptotic food intake than females at 23 and 30°C (F2,51=3.3, P<0.05, Tukey's HSD, P<0.05). No significant differences in litter size and PRL levels were observed between the three groups; however, litter mass at 5°C was lower by 19.7 and 19.8% than litter mass at 23 and 30°C on day 19 of lactation (F2,51=3.5, P<0.05, Tukey's HSD, P<0.05). Differences in the above parameters between 23 and 30°C were not significant. Litter mass was positively correlated with asymptotic food intake (23°C, r=0.60, P<0.05; 30°C, r=0.94, P<0.01; 5°C, r=0.77, P<0.01). These data suggested that females lactating at cold temperatures increased food intake to compensate for additional energy demands for thermogenesis, but they might not be capable of exporting more energy as milk to the pups, indicating a possible consistency with the peripheral hypothesis. However, the present results do not considerably distinguish the peripheral limitation hypothesis from the heat dissipation limits hypothesis.© 2011 Published by The Company of Biologists Ltd.
Li X.,Liaocheng University
Oncogene | Year: 2016
Glioblastoma multiforme (GBM) is the most common primary malignant brain cancer in adults. However, the molecular events underlying carcinogenesis and their interplay remain elusive. Here, we report that the stability of Ubiquitin-conjugating enzyme E2S (UBE2S) is regulated by the PTEN/Akt pathway and that its degradation depends on the ubiquitin-proteasome system. Mechanistically, Akt1 physically interacted with and phosphorylated UBE2S at Thr 152, enhancing its stability by inhibiting proteasomal degradation. Additionally, accumulated UBE2S was found to be associated with the components of the non-homologous end-joining (NHEJ) complex and participated in the NHEJ-mediated DNA repair process. The association of Ku70 with UBE2S was enhanced, and the complex was recruited to double-stranded break (DSB) sites in response to etoposide treatment. Furthermore, knockdown of UBE2S expression inhibited NHEJ-mediated DSB repair and rendered glioblastoma cells more sensitive to chemotherapy. Overall, our findings provide a novel drug target that may serve as the rationale for the development of a new therapeutic approach.Oncogene advance online publication, 5 September 2016; doi:10.1038/onc.2016.281. © 2016 Macmillan Publishers Limited, part of Springer Nature.
Zhang X.,Liaocheng University
Knowledge-Based Systems | Year: 2011
The paper introduces the concepts of dual disjunctive normal forms in classical logic and fuzzy logics with involution negation. The laws of their truth values are studied. One is called duality, the other is called pseudo duality. Dual disjunctive normal forms in classical logic hold duality, and dual disjunctive normal forms in fuzzy logics with involution negation hold either duality or pseudo duality. © 2011 Elsevier B.V. All rights reserved.
Zhao Z.-J.,Liaocheng University
Physiological and Biochemical Zoology | Year: 2011
Leptin has been found to be a direct participant in the regulation of both energy intake and energy expenditure in small mammals showing seasonal declines in body mass (M b) and fat mass, but its roles in an animal exhibiting seasonally increased thermogenesis and unchanged M b remain unclear. Serum leptin levels, energy budget, and thermogenesis were measured in striped hamsters exposed to consecutive decreases in ambient temperatures ranging from 23° to -23°C. Coldexposed hamsters had significant increases in gross energy intake (GEI), the rate of basal metabolism, nonshivering thermogenesis, and activity of cytochrome c oxidase (COX) in brown adipose tissue (BAT), compared with control hamsters, indicating a cold-induced elevation of thermogenesis. Body mass and fat content were decreased in cold-exposed animals, and serum leptin levels were increased in hamsters exposed to temperatures of -8°C and below in inverse proportion to body fat content. Serum leptin levels were positively correlated with GEI and BAT COX activity in cold-exposed hamsters, but no such relationships were observed in control animals. These findings suggest that cold-exposed hamsters increase food consumption to meet the energy requirements for increased BAT thermogenesis. The increases in serum leptin levels are likely involved in increased thermogenesis in hamsters under cold stress. Cold-exposed hamsters may become leptin resistant, which is associated with impaired regulation of food intake. This new natural model of leptin resistance may also provide insight into the dynamic long-term control of energy homeostasis for animals that do not exhibit seasonal decline in M b. © 2011 by The University of Chicago.
Wen L.H.,Liaocheng University |
Luo X.B.,Jinggangshan University
Laser Physics Letters | Year: 2012
We investigate the dynamics of vortex formation and the structure of vortex lattices in a Bose-Einstein condensate confined within a rotating double-well (DW) potential. The dynamical process is a formation process of "ghost" vortices, "hidden" vortices, and "visible" vortices. The critical rotation frequency for the creation of visible vortex is indicated by a sudden jump in the angular momentum evolution and an inflexion in the energy evolution. Different visible vortex structures can be formed by ruling the rotation frequency. In particular, structural change of visible vortex patterns can be achieved by regulating the anisotropy parameter of the DW potential. This feature allows to flexibly control the distribution of angular momentum in macroscopic quantum systems and study the interplay among rotation, interparticle interaction and external potential in superfluids. © 2012 by Astro, Ltd.
Peng X.-Q.,Liaocheng University
Applied Biochemistry and Biotechnology | Year: 2013
To expand the functionality of lipase B from Candida antarctica (CALB), we used the multi-site saturation mutagenesis methods to create CALB mutants with improved thermal stability. The times of residual activity of the mutants mCALB168 and mCALB7 were 14 and 6 times higher than that of the displayed WT-CALB at 60 C. Amino acid substitutions at positions 218, 219, 220, and 221 in mCALB7 introduced two additional hydrogen bonds and altered part of the surface domain from 217 to 224. In mCALB168, we introduced mutations T57A/R168K, which formed three additional hydrogen bonds. The mutants displayed on yeast significantly increased the thermostability in an aqueous system at 60 C. These results indicate that yeast surface display technology could dramatically improve the stability of CALB. © 2012 Springer Science+Business Media New York.