Vehicle Representation and Classification of Surveillance Video Based on Sparse Learning

We cast vehicle recognition as problem of feature representation and classification, and introduce a sparse learning based framework for vehicle recognition and classification in this paper. After objects captured with a GMM background subtraction program, images are labeled with vehicle type for dictionary learning and decompose the images with sparse coding （SC）, a linear SVM trained with the SC feature for vehicle classification. A simple but efficient active learning stategy is adopted by adding the false positive samples into previous training set for dictionary and SVM model retraining. Compared with traditional feature representation and classification realized with SVM, SC method achieves dramatically improvement on classification accuracy and exhibits strong robustness. The work is also validated on real-world surveillance video.

太赫兹主动关联成像技术研究

研究了一种基于主动关联成像方式的太赫兹成像系统,可利用一个太赫兹单点探测器实现目标的高速、高分辨二维成像,突破了太赫兹器件的分辨率限制。该系统采用双调幅板旋转方式产生可重复使用的测量矩阵,大幅提高了成像速度。通过数值模拟给出了成像距离、调幅板随机图形尺寸、采样次数、采样矩阵相关性等参数对成像结果的影响,得到最佳实验参数,并优化了双调幅板的运动策略。搭建的太赫兹主动关联成像实验装置采用波长为3mm的太赫兹源,实验证明其成像分辨率为4mm,且成像时间由调幅板的电机转速决定,证实了此种太赫兹成像方式的可行性。

Variants of genes encoding collagens and matrix metalloproteinase system increased the risk of aortic dissection

Aortic dissection （AD） is a devastating, heterogeneous condition of aorta. The homeostasis between collagens and matrix metalloproteases （MMPs）/tissue inhibitors of MMPs （TIMPs） system in the extracellular matrix plays an important role for structure and functions of aorta. However, our knowledge on association between variants of genes in this system and pathogenesis of AD is very limited. We analyzed all yet known coding human genes of collagens （45 genes）, MMPs/TIMPs （27 genes） in 702 sporadic AD patients and in 163 matched healthy controls, by using massively targeted next-generation and Sanger sequencing. To define the pathogenesis of potential disease-causing candidate genes, we performed transcriptome sequencing and pedigree co-segregation analysis in some genes and generated Col5a2 knockout rats. We identified 257 pathogenic or likely pathogenic variants which involved 88.89% （64/72） genes in collagens-MMPs/TIMPs system and accounted for 31.05% （218/702） sporadic AD patients. In them, 84.86% patients （185/218） carried one variant, 12.84% two variants and 2.30% more than two variants. Importantly, we identified 52 novel probablY pathogenic loss-of-function （LOF） variants （20 nonsense, 16 frameshift, 14 splice sites, one stop-loss, one initiation codon） in 11.06% （50/452） AD patients, which were absent in 163 controls （P=2.5-10-5）. Transcriptome sequencing revealed that identified variants induced dyshomeostasis in expression of collagens-TIMPs/MMPs systems. The Col5a2-/- rats manifested growth retardation and aortic dysplasia. Our study provides a first comprehensive map of genetic alterations in collagens-MMPs/TIMPs system in sporadic AD patients and suggests that variants of these genes contribute largely to AD pathogenesis.

Transcriptome-wide identification of differentially expressed genes and long non-coding RNAs in nitroglycerin-tolerant rat aorta

Tolerance to nitroglycerin(GTN)greatly limits its long-time application,and the underlying mechanism remains largely unexplored.In the present study,we aimed to investigate the comprehensive changes in the transcriptome of rat aorta tolerant to GTN by analyzing lncRNA expression.We employed the RNA sequencing(RNA-seq)technique to identify mRNAs and lncRNAs.Ingenuity pathway analysis(IPA)was used for pathway and functional analysis.RT-qPCR was used to validate the RNA-seq results.We identified 22788 genes(reads per kilobase million[RPKM]>0.1,14720 protein-coding genes and 4408 lncRNAs),including 115 differentially expressed(DE)mRNAs(65 up-regulated and 50 down-regulated)and 104 DE lncRNAs(56 up-regulated and 48 down-regulated),in GTN-tolerant aortas.IPA revealed the inhibition of a canonical pathway“Signaling by Rho Family GTPases”and alteration in six upstream regulators.Functional analysis showed that 11 genes were related to“disorder of blood pressure”.We predicted the cis-target genes of DE lncRNAs by the analysis of their neighboring genes.The results revealed the 28 DE lncRNAs adjacent to the 26 protein-coding genes.Many DE mRNAs and cis-target genes of DE lncRNAs have been implicated in the regulation of blood pressure or cell contraction.These results suggested that the dysregulated mRNAs and lncRNAs contributed to the development of GTN tolerance and could serve as potential targets to prevent and reverse GTN tolerance.