Dark Septate Endophyte (DSE) Fungi Isolated from Metal Polluted Soils: Their Taxonomic Position, Tolerance, and Accumulation of Heavy Metals In Vitro

Yujie Zhang,Yan Zhang,Maojun Liu,Xiaodong Shi,Zhiwei Zhao 한국미생물학회 2008 The journal of microbiology Vol.46 No.6

To understand the possible role of the plant root associated fungi on metal tolerance, their role in the uptake of heavy metals and the potential transfer of these metal ions to the plant, three strains of dark septate endophytic (DSE) fungi were isolated from a waste smelter site in southwest China, and one strain was isolated from a non-contaminated site. According to molecular phylogenetic analysis of the ITS 1-5.8S rDNA-ITS 2 gene regions and morphological characteristics, one is identified as Exophiala pisciphila, and the other three are non-sporulating fungi under the experiment condition with the nearest phylogenetic affinities to the Thysanorea papuana strain EU041814. Tolerance and accumulation abilities of the three DSE strains for metals were investigated in liquid culture. Minimum inhibitory concentrations (MIC) of Pb, Zn, and Cd were determined. It was demonstrated that the tolerance of the DSE strains varied between metal species and strains. The E. pisciphila strain is able to accumulate lead and cadmium over 20% and 5% of dry weight of biomass, respectively. Partial of the sequestrated metals can be washed with CaCl2. Morphological and enzyme activity changes taking place in the presence of excessive Pb, Cd, and/or Zn also indicate that the mechanism of heavy metal tolerance and accumulation of the DSE strains would be a complex process. The findings indicated promising tolerance and accumulation of the DSE strains with potential values in metal cycling and restoration of soil and water system.

Mechanical Behavior in Perfobond Rib Shear Connector with UHPC-Steel Composite Structure with Coarse Aggregate

Maojun Duan,Shiyu Zhang,Xu Wang,Fenghui Dong 대한토목학회 2020 KSCE JOURNAL OF CIVIL ENGINEERING Vol.24 No.4

Using experimental and numerical analysis, this paper aims at investigating the mechanical behavior in Perfobond rib (PBL) shear connectors with ultrahigh-performance concrete (UHPC)-steel composite structures. Twelve push-out specimens fabricated according to the design used for the connectors in the UHPC-steel composite structures in bridges have been investigated. The main objective of this paper was to discuss the mechanism of failure and the influence of different parameters on PBL shear connectors mechanical properties, including the diameter of transverse rebar, hole spacing and number of holes. The results showed that the failure mode of this type is different from that of conventional concrete specimens. During the failure of specimens, there are few cracks and the overall stiffness still maintain a high level, and reveal that a balance between the size of transverse rebar and the diameter of the hole. In addition, the basic form of the ultimate bearing capacity of existing PBL shearing bonds is summarized, and a new concept of steel fiber shearing in UHPC is proposed. Finally, based on the elastic foundation beam model, the full curve calculation formula of UHPC single-hole PBL shear bond is derived by using Timoshenko beam element. The formula calculation results are in good agreement with the experimental values.

High-frame-rate Video Denoising for Ultra-low Illumination

( Xin Tan ),( Yu Liu ),( Zheng Zhang ),( Maojun Zhang ) 한국인터넷정보학회 2014 KSII Transactions on Internet and Information Syst Vol.8 No.11

In this study, we present a denoising algorithm for high-frame-rate videos in an ultra-low illumination environment on the basis of Kalman filtering model and a new motion segmentation scheme. The Kalman filter removes temporal noise from signals by propagating error covariance statistics. Regarded as the process noise for imaging, motion is important in Kalman filtering. We propose a new motion estimation scheme that is suitable for serious noise. This scheme employs the small motion vector characteristic of high-frame-rate videos. Small changing patches are intentionally neglected because distinguishing details from large-scale noise is difficult and unimportant. Finally, a spatial bilateral filter is used to improve denoising capability in the motion area. Experiments are performed on videos with both synthetic and real noises. Results show that the proposed algorithm outperforms other state-of-the-art methods in both peak signal-to-noise ratio objective evaluation and visual quality.

Single Pixel Compressive Camera for Fast Video Acquisition using Spatial Cluster Regularization

( Yang Peng ),( Yu Liu ),( Kuiyan Lu ),( Maojun Zhang ) 한국인터넷정보학회 2018 KSII Transactions on Internet and Information Syst Vol.12 No.11

Single pixel imaging technology has developed for years, however the video acquisition on the single pixel camera is not a well-studied problem in computer vision. This work proposes a new scheme for single pixel camera to acquire video data and a new regularization for robust signal recovery algorithm. The method establishes a single pixel video compressive sensing scheme to reconstruct the video clips in spatial domain by recovering the difference of the consecutive frames. Different from traditional data acquisition method works in transform domain, the proposed scheme reconstructs the video frames directly in spatial domain. At the same time, a new regularization called spatial cluster is introduced to improve the performance of signal reconstruction. The regularization derives from the observation that the nonzero coefficients often tend to be clustered in the difference of the consecutive video frames. We implement an experiment platform to illustrate the effectiveness of the proposed algorithm. Numerous experiments show the well performance of video acquisition and frame reconstruction on single pixel camera.

A putative pathogen-resistant regulatory pathway between MicroRNAs and candidate target genes in maize

Jian Gao,Mao Luo,Chun Zhang,Hua Peng,Haijian Lin,Yaou shen,Maojun Zhao,Guangtang Pan,Zhiming Zhang 한국식물학회 2015 Journal of Plant Biology Vol.58 No.4

MicroRNAs (miRNAs) are a family of small non-coding RNAs that, in most cases, negatively regulate gene expression at the post-transcriptional level. Plant miRNAs have been implicated in developmental processes and adaptation to environmental stress including biotic and abiotic stresses. Here, we report a comprehensive analysis of miRNAs and associated target genes under banded leaf and sheath blight (BLSB) stress caused by R. solani in maize. Eight differentially expressed miRNAs were randomly selected from deep sequencing results and validated by qRT-PCR together with their putative target genes, most of which are transcription factors as well as metabolic genes involved in auxin signaling. The results revealed that majorities of the analyzed miRNAs show an inverse correlation with their corresponding predicted target genes. In addition, a putative regulatory network of miRNAs-mRNAs responsive to R. solani was constructed. This study provides insight into the regulatory functions of miRNAs, thereby expanding our knowledge of the molecular mechanisms of pathogen resistance.

A Kalman Filter based Video Denoising Method Using Intensity and Structure Tensor

( Yu Liu ),( Chenlin Zuo ),( Xin Tan ),( Huaxin Xiao ),( Maojun Zhang ) 한국인터넷정보학회 2014 KSII Transactions on Internet and Information Syst Vol.8 No.8

We propose a video denoising method based on Kalman filter to reduce the noise in video sequences. Firstly, with the strong spatiotemporal correlations of neighboring frames, motion estimation is performed on video frames consisting of previous denoised frames and current noisy frame based on intensity and structure tensor. The current noisy frame is processed in temporal domain by using motion estimation result as the parameter in the Kalman filter, while it is also processed in spatial domain using the Wiener filter. Finally, by weighting the denoised frames from the Kalman and the Wiener filtering, a satisfactory result can be obtained. Experimental results show that the performance of our proposed method is competitive when compared with state-of-the-art video denoising algorithms based on both peak signal-to-noise-ratio and structural similarity evaluations.

A comparative study on antioxidant, anti-inflammatory, antimicrobial activities and chemical composition of Pyrus ussuriensis cultivars from northeastern China

Xiaoqian Wang,Chunyan Liu,Qiang Wang,Chang Liu,Huili Sun,Maojun Zhang,Deguo Lyu,Guodong Du 한국원예학회 2021 Horticulture, Environment, and Biotechnology Vol.62 No.3

Pyrus ussuriensis is the most important cultivated pear in the northeastern, cold areas of China. However, studies on thebiological activity of Pyrus ussuriensis fruit are rare in the public domain. The present study compared antioxidant, antiinflammatory, and antimicrobial activities and chemical composition in tissues from the peel and fl esh of nine Pyrus ussuriensiscultivars. The chemical composition diff ered among cultivars and tissue sources. Phenolics were predominant in peelsamples, whereas sugars were predominant in fl esh samples. Twenty-one phenolic compounds were identifi ed and quantifi ed,including hydroxycinnamic acids, hydroquinones, fl avanols, fl avonols, fl avones, and anthocyanins (only in peel samples). The total phenolic content ranged between 363.0 and 1734.0 mg kg − 1 FW in the peel and from 28.5 to 182.3 mg kg − 1 FWin the fl esh. In addition, cultivars with high total phenolic and fl avonoid contents had signifi cantly higher antioxidant activities. The in vitro anti-infl ammatory study, performed using an egg albumin denaturation assay, demonstrated that both peeland fl esh samples had strong activity, which was comparable with that of the standard anti-infl ammatory drug diclofenacsodium. The antimicrobial results showed that ‘Jianba’ and ‘Balixiang’ cultivars exhibited strong activity against bacteriastrains in the peel and fl esh, respectively. The present study provided information for selecting promising Pyrus ussuriensiscultivars with improved health benefi ts.

Background Subtraction for Moving Cameras based on trajectory-controlled segmentation and Label Inference

( Xiaoqing Yin ),( Bin Wang ),( Weili Li ),( Yu Liu ),( Maojun Zhang ) 한국인터넷정보학회 2015 KSII Transactions on Internet and Information Syst Vol.9 No.10

We propose a background subtraction method for moving cameras based on trajectory classification, image segmentation and label inference. In the trajectory classification process, PCA-based outlier detection strategy is used to remove the outliers in the foreground trajectories. Combining optical flow trajectory with watershed algorithm, we propose a trajectory-controlled watershed segmentation algorithm which effectively improves the edge-preserving performance and prevents the over-smooth problem. Finally, label inference based on Markov Random field is conducted for labeling the unlabeled pixels. Experimental results on the motionseg database demonstrate the promising performance of the proposed approach compared with other competing methods.

A Noisy Videos Background Subtraction Algorithm Based on Dictionary Learning

( Huaxin Xiao ),( Yu Liu ),( Shuren Tan ),( Jiang Duan ),( Maojun Zhang ) 한국인터넷정보학회 2014 KSII Transactions on Internet and Information Syst Vol.8 No.6

Most background subtraction methods focus on dynamic and complex scenes without considering robustness against noise. This paper proposes a background subtraction algorithm based on dictionary learning and sparse coding for handling low light conditions. The proposed method formulates background modeling as the linear and sparse combination of atoms in the dictionary. The background subtraction is considered as the difference between sparse representations of the current frame and the background model. Assuming that the projection of the noise over the dictionary is irregular and random guarantees the adaptability of the approach in large noisy scenes. Experimental results divided in simulated large noise and realistic low light conditions show the promising robustness of the proposed approach compared with other competing methods.

A Novel Video Stitching Method for Multi-Camera Surveillance Systems

( Xiaoqing Yin ),( Weili Li ),( Bin Wang ),( Yu Liu ),( Maojun Zhang ) 한국인터넷정보학회 2014 KSII Transactions on Internet and Information Syst Vol.8 No.10

This paper proposes a novel video stitching method that improves real-time performance and visual quality of a multi-camera video surveillance system. A two-stage seam searching algorithm based on enhanced dynamic programming is proposed. It can obtain satisfactory result and achieve better real-time performance than traditional seam-searching methods. The experiments show that the computing time is reduced by 66.4% using the proposed algorithm compared with enhanced dynamic programming, while the seam-searching accuracy is maintained. A real-time local update scheme reduces the deformation effect caused by moving objects passing through the seam, and a seam-based local color transfer model is constructed and applied to achieve smooth transition in the overlapped area, and overcome the traditional pixel blending methods. The effectiveness of the proposed method is proved in the experiements.