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CCR2 plays important roles in many inflammatory and bone metabolic diseases, but its specific role in periodontitis is unknown. In the present study, we aimed to explore the role of CCR2 in the progression of periodontitis and evaluate the effect of cenicriviroc (CVC) on periodontitis.The expression of CCR2 was studied in patients with periodontitis and in ligation-induced murine model of periodontitis. The role of CCR2 in promoting inflammation and bone resorption in periodontitis was evaluated in Ccr2sup-/-/supmice and wild-type mice. The effect of CVC in the prevention and treatment of periodontitis was evaluated by systemic and local medication. Microcomputed tomography, haematoxylin and eosin staining, tartrate-resistant acid phosphatase staining, quantitative real-time polymerase chain reaction, enzyme-linked immunosorbent assay, and flow cytometry were used for histomorphology, molecular biology, and cytology analysis, respectively.In this study, we demonstrated that CCR2 was highly expressed in human and murine periodontitis and that CCR2 deficiency was associated with decreased inflammatory monocyte and macrophage infiltration and inflammatory mediators, osteoclast number and alveolar bone resorption. Prevention and treatment with CVC significantly reduced the severity of periodontitis, regardless of whether it was administered systemically or locally.CCR2 plays an important role in the development and progression of periodontitis, and CVC is a potential drug for the prevention and treatment of periodontitis.

FAM19A5/TAFA5 is a member of the family with sequence similarity 19 with unknown function in emotional and cognitive regulation. Here, we reported that FAM19A5 was highly expressed in the embryonic and postnatal mouse brain, especially in the hippocampus. Behaviorally, genetic deletion of Fam19a5 resulted in increased depressive-like behaviors and impaired hippocampus-dependent spatial memory. These behavioral alterations were associated with the decreased expression of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors and N-methyl-D-aspartic acid receptors, as well as significantly reduced glutamate release and neuronal activity in the hippocampus. Subsequently, these changes led to the decreased density of dendritic spines. In recent years, the roles of chronic stress participating in the development of depression have become increasingly clear, but the mechanism remains to be elucidated. We found that the levels of FAM19A5 in plasma and hippocampus of chronic stress-treated mice were significantly decreased whereas overexpression of human FAM19A5 selectively in the hippocampus could attenuate chronic stress-induced depressive-like behaviors. Taken together, our results revealed for the first time that FAM19A5 plays a key role in the regulation of depression and spatial cognition in the hippocampus. Furthermore, our study provided a new mechanism for chronic stress-induced depression, and also provided a potential biomarker for the diagnosis and a new strategy for the treatment of depression.

Background & Aims C-C motif chemokine receptor 2 (CCR2) has been recognized as a promising target for the treatment of liver fibrosis. PC3-secreted microprotein (PSMP)/microseminoprotein (MSMP) is a novel chemotactic cytokine and its receptor is CCR2. In the present study we investigated the expression and role of PSMP in liver fibrosis/cirrhosis. Methods PSMP expression was studied in patients with fibrosis/cirrhosis and in 3 murine models of liver fibrosis, including mice treated with carbon tetrachloride (CCl4), bile-duct ligation, or a 5-diethoxycarbonyl-1,4-dihydrocollidine diet. The role of PSMP was evaluated in Psmp-/- mice and after treatment with a PSMP antibody in wild-type mice. The direct effects of PSMP on macrophages and hepatic stellate cells were studied in vitro. Results In this study, we found that PSMP was highly expressed in fibrotic/cirrhotic tissues from patients with different etiologies of liver disease and in the 3 experimental mouse models of fibrosis. Damage-associated molecular pattern molecules HMGB-1 and IL-33 induced hepatocytes to produce PSMP. PSMP deficiency resulted in a marked amelioration of hepatic injury and fibrosis. In CCl4-induced hepatic injury, the infiltration of macrophages and CCR2+ monocytes into the liver was significantly decreased in Psmp-/- mice. Consistent with the decreased levels of intrahepatic macrophages, proinflammatory cytokines were significantly reduced. Moreover, adeno-associated virus-8 vectors successfully overexpressing human PSMP in Psmp-/- mouse livers could reverse the attenuation of liver injury and fibrosis induced by CCl4 in a CCR2-dependent manner. Treatment with a specific PSMP-neutralizing antibody, 3D5, prevented liver injury and fibrosis induced by CCl4 in mice. At the cellular level, PSMP directly promoted M1 polarization of macrophages and activation of LX-2 cells. Conclusion PSMP enhances liver fibrosis through its receptor, CCR2. PSMP is a potentially attractive therapeutic target for the treatment of patients with liver fibrosis. Lay summary Our present study identifies the essential role of the protein PSMP for the development and progression of liver fibrosis in humans and mice. PSMP promotes liver fibrosis through inflammatory macrophage infiltration, polarization and production of proinflammatory cytokines, as well as direct activation of hepatic stellate cells via its receptor CCR2. A PSMP antibody can significantly reduce liver fibrosis development in vivo. These findings indicate that PSMP is a potential therapeutic target and its antibody is a potential therapeutic agent for the treatment of liver fibrosis.

Shasha Yuan,1 Cui Wang,1 Wenting Jiang,1 Yiping Wei,1 Qingqing Li,2,3 Zhanming Song,2,3 Siqi Li,1 Fei Sun,1 Zhongtian Liu,2,3 Ying Wang,2,3 Wenjie Hu1,4 1Department of Periodontology, National Clinical Research Center for Oral Diseases, National Engineering Laboratory for Digital and Material Technology of Stomatology, Beijing Key Laboratory of Digital Stomatology, Peking University School and Hospital of Stomatology, Beijing, People’s Republic of China; 2Department of Immunology, School of Basic Medical Sciences, and NHC Key Laboratory of Medical Immunology, Peking University, Beijing, People’s Republic of China; 3Center for Human Disease Genomics, Peking University, Beijing, People’s Republic of China; 4NHC Research Center of Engineering and Technology for Computerized Dentistry, Beijing, People’s Republic of ChinaCorrespondence: Ying Wang, Department of Immunology, School of Basic Medical Sciences, and NHC Key Laboratory of Medical Immunology, Peking University, No. 38, College Road, Haidian District, Beijing, People’s Republic of China, Tel +86 10 8280115, Email yw@bjmu.edu.cn Wenjie Hu, Department of Periodontology, National Clinical Research Center for Oral Diseases, National Engineering Laboratory for Digital and Material Technology of Stomatology, Beijing Key Laboratory of Digital Stomatology, Peking University School and Hospital of Stomatology, No. 22, Zhongguancun South Street, Haidian District, Beijing, People’s Republic of China, Tel +86 10 82195374, Email huwenjie@pkuss.bjmu.edu.cnObjective: This investigation aimed to determine whether and to what extent there are transcriptional differences between periodontitis and peri-implantitis in the same susceptible host.Background: As an immune-mediated inflammatory disease resulting in aggressive bone resorption around dental implants, peri-implantitis constitutes a major threat to dental implants’ long-term success. Compared to periodontitis, its etiological molecular mechanism remains elusive. Currently, there are few investigations on these two diseases at the transcriptional level within the same basal environment.Methods: Ligature-induced peri-implantitis and periodontitis were generated in the same mice. Gingival tissues of healthy, periodontitis, and peri-implantitis sites from the same oral cavity were collected and used for RNA sequencing. Differentially expressed genes (DEGs) were screened between periodontitis/peri-implantitis and healthy sites. Enrichment analysis of DEGs was performed. The comprehensive immune landscape was annotated by seq-ImmuCC. Hub genes from peri-implantitis-specific DEGs were filtered using the STRING database and Cytoscape. Validation of the selected hub genes was performed on the GEO106090 dataset (gingival tissues from six periodontitis patients, six peri-implantitis patients, and six healthy controls).Results: The results indicated that peri-implantitis and periodontitis exhibited significantly distinct transcriptional signatures, with the complement and coagulation cascade pathways and osteoclast differentiation predominating in peri-implantitis mucosa. Compared with periodontitis, peri-implantitis sites exhibited elevated macrophage proportions and relatively enriched macrophage activation and bone loss. Hub genes were selected, and IL1B, CCL3, and CLEC4E were significantly highly expressed in human peri-implantitis mucosa.Conclusion: The study suggests that the interplay between macrophages and bone resorption seems to be more robust than in periodontitis. IL1B, CCL3, and CLEC4E may be considered promising therapeutic targets for peri-implantitis. These critical biological processes and identified genes may contribute to the etiology of peri-implantitis, which is unique from periodontitis. This work may make way for deeper exploration and contribute significantly to the treatment and prevention of peri-implantitis.Keywords: peri-implantitis, periodontitis, transcriptome analysis, immune profiling, bioinformatics analysis

The trinucleotide repeat containing 6 (TNRC6) family of proteins are core components of RNA interference (RNAi) and consist of three paralogs (TNRC6A, TNRC6B, and TNRC6C). The TNRC6 paralogs associate with argonaute (AGO) protein, the core RNAi factor, and bridge its interactions with other proteins. We obtained TNRC6A and TNRC6B single and double knockout cell lines to investigate how the TNRC6 paralogs contribute to RNAi. We found that TNRC6 proteins are not required for gene silencing when duplex RNAs are fully complementary. TNRC6 expression was necessary for regulation by a microRNA. TNRC6A, but not TNRC6B, expression was necessary for transcriptional activation by a duplex RNA targeting a gene promoter. By contrast, AGO2 is required for all three gene expression pathways. TNRC6A can affect the Dicer localization in cytoplasm versus the nucleus, but none of the three TNRC6 paralogs was necessary for nuclear localization of AGO2. Our data suggest that the roles of the TNRC6 paralogs differ in some details and that TNRC6 is not required for clinical therapeutic silencing mechanisms that involve fully complementary duplex RNAs.

Our previous study has demonstrated that recombinant yeast can induce specific immune responses in Carassius auratus and may serve as a potential carrier for oral DNA vaccines in aquaculture. In this study, we further developed an effective yeast-based oral DNA vaccine against the bacteria Aeromonas hydrophila, which was expected to provide protection from the motile aeromonad septicemia (MAS). First, two candidate antigen genes, ompG and omp48, were cloned from the Aeromonas hydrophila genome DNA. Then, relative yeast-eukaryote shuttle vectors were constructed and their expression in eukaryotes was validated. Next, crucian carps were orally administered with ompG or omp48 recombinant yeast, and the expression of the genes in the intestinal mucosa was confirmed by immunohistochemistry (IHC). The specific immune responses were further detected by Western blot and enzyme-linked immunosorbent assay (ELISA). The ELISA results showed that the production of the OVA-specific antibody in the OVA-ompG group was significantly higher than that of the OVA-omp48 group, indicating that the OVA-ompG group elicited obviously stronger immune response than OVA-omp48. Finally, the challenge experiment against Aeromonas hydrophila infection demonstrated decreased fish mortality rate after the oral administration of the OVA-ompG yeast vaccine. In conclusion, our work provided a framework for the further development of oral yeast-based fishery vaccines.

Antisense oligonucleotides (ASOs) are versatile agents for controlling the translation and splicing of mRNA. ASOs have the potential to control the expression of every gene, providing a versatile platform for the development of therapeutic agents. Unlocking this potential requires understanding the mechanisms of action of ASOs. Most ASOs function by one of two mechanisms. Some recruit RNase H and promote cleavage of an RNA target. Others bind and block RNAs to prevent translation or redirect alternative splicing. Understanding the mechanism is crucial to optimization of function and the design of effective ASOs as experimental tools and therapeutics.

As a complex and safety-critical system, any failure in the Next Generation Train Control System (NGTC) departure scenario may cause serious personal injuries and property losses. It is very necessary to study NGTC scenario scheme and effective modeling and verification methods. This paper investigates the key technologies of the NGTC, optimizes the system structure and redistribution functions, and proposes the train control system scheme and typical operating scenarios. Firstly, the structure, equipment function and information interaction of NGTC are analyzed, and the operation scenarios of the system scheme are designed. This paper also uses UML language to describe the train departure scenario, and uses NuSMV modeling to verify accessibility and certainty of the scenario scheme. The results show that, the scheme proposed in this paper provides a reference for the design and implementation of the NGTC.

Yeast is considered as a simple and cost-effective host for protein expression, and our previous studies have proved that Saccharomyces cerevisiae can deliver recombinant protein and DNA into mouse dendritic cells and can further induce immune responses as novel vaccines. In order to know whether similar immune responses can be induced in rabbit by oral administration of such recombinant S. cerevisiae vaccine, we orally fed the rabbits with heat-inactivated myostatin-recombinant S. cerevisiae for 5 weeks, and then myostatin-specific antibody in serum was detected successfully by western blotting and ELISA assay. The rabbits treated with myostatin-recombinant S. cerevisiae vaccine grew faster and their muscles were much heavier than that of the control group. As a common experimental animal and a meat livestock with great economic value, rabbit was proved to be the second animal species that have been successfully orally immunized by recombinant S. cerevisiae vaccine after mice.

GW182 and argonaute 2 (AGO2) are core proteins of the RNA interference (RNAi) complex. GW182 is a scaffolding protein that physically associates with AGO2 and bridges its interactions with other proteins. A fundamental problem in biology is how scaffolding proteins adapt or contribute to differing functional demands within cells. Here we test the necessity for human GW182 proteins (paralogs TNRC6A, TNRC6B, and TNRC6C) for several mechanisms of small duplex RNA-mediated control of gene expression, including translational silencing by miRNAs, translational silencing by siRNAs, transcriptional silencing, transcriptional activation, and splicing. We find that GW182 is required for transcriptional activation and for the activity of miRNAs, but is dispensable for the regulation of splicing, transcriptional silencing, and the action of siRNAs. AGO2, by contrast, is necessary for each of these processes. Our data suggests that GW182 does not alter AGO2 to make it active. Instead, GW182 organizes protein complexes around AGO2. Sometimes this higher level of organization is necessary and sometimes it is not. AGO2 and GW182 offer an example for how a partnership between a scaffolding protein and a functional protein can be powerful but not obligatory.

Friedreich's Ataxia (FA) is an inherited neurologic disorder caused by an expanded GAA repeat within intron 1 of the frataxin (FXN) gene that reduces expression of FXN protein. Agents that increase expression of FXN have the potential to alleviate the disease. We previously reported that duplex RNAs (dsRNAs) and antisense oligonucleotides (ASOs) complementary to the GAA repeat could enhance expression of FXN protein. We now explore the potential of a diverse group of chemically modified dsRNAs and ASOs to define the breadth of repeat-targeted synthetic nucleic acids as a platform for therapeutic development for FA. ASOs and dsRNAs can activate FXN protein expression in FA patient-derived cell lines that possess varied numbers of GAA repeats. Increased FXN protein expression was achieved by ASOs incorporating diverse chemical modifications with low nanomolar potencies, suggesting substantial flexibility in choosing compounds for further chemical optimization and animal studies. Our data encourage further development of ASOs as agents to treat FA.

China Railway Corporation proposes the upgrading and updating plan of general speed train (train running speed under 160 km/h) to improve the outdated status of general speed railway. The new CTCS-1 Automatic Train Protection (ATP) system will be safer, more reliable and advanced than the existing train control system. In this paper, enhanced Bayesian Network (BN) is first used in CTCS-1 ATP RAM assessment, which is mainly used to analyze the structure of two different ATPs and establish the corresponding enhanced BN models. Finally, the Reliability, Availability, and Maintainability (RAM) of these two different ATPs are obtained and analyzed through enhanced BN simulation model. The assessment results show that the RAM indicators of CTCS-1 modular redundancy ATP and system redundancy ATP can satisfy the requirements of Chinese train control system requirement specifications, but the RAM indicators of CTCS-1 modular redundancy ATP are better than CTCS-1 system redundancy ATP.

Gene cloning and vector construction are basic technologies in modern molecular biology for gene functional study. Here, we present flexible and efficient strategies for gene cloning and vector construction using overlap PCR. We firstly cloned the open reading frames (ORFs) of the porcine MSTN, chicken OVA and human α-glucosidase genes by overlap PCR-based assembling of their exons, which could be amplified with genomic DNAs as the templates without RNA extraction and RT-PCR reaction. Secondly, we generated additionally three designed functional cassettes by overlap PCR-based assembling of different DNA elements, which facilitated the construction their expression vectors greatly. Moreover, we further developed an interesting overlap-circled PCR method for fast plasmid vector construction without any cutting and ligating procedure. These advanced applications of overlap PCR provide useful alternative tools for gene cloning and vector construction.

Precise genome editing with desired point mutations can be generated by CRISPR/Cas9-mediated homology-directed repair (HDR) and is of great significance for gene function study, gene therapy and animal breeding. However, HDR efficiency is inherently low and improvements are necessitated. Herein, we determined that the HDR efficiency could be enhanced by expressing Rad52, a gene that is involved in the homologous recombination process. Both the Rad52 co-expression and Rad52-Cas9 fusion strategies yielded approximately 3-fold increase in HDR during the surrogate reporter assays in human HEK293T cells, as well as in the genome editing assays. Moreover, the enhancement effects of the Rad52-Cas9 fusion on HDR mediated by different (plasmid, PCR and ssDNA) donor templates were confirmed. We found that the HDR efficiency could be significantly improved to about 40% by the combined usage of Rad52 and Scr7. In addition, we also applied the fusion strategy for modifying the IGF2 gene of porcine PK15 cells, which further demonstrated a 2.2-fold increase in HDR frequency. In conclusion, our data suggests that Rad52-Cas9 fusion is a good option for enhancing CRISPR/Cas9-mediated HDR, which may be of use in future studies involving precise genome editing.

The clustered regularly interspaced short palindromic repeats (CRISPR) system has recently been developed into a powerful genome-editing technology, as it requires only two key components (Cas9 protein and sgRNA) to function and further enables multiplex genome targeting and homology-directed repair (HDR) based precise genome editing in a wide variety of organisms. Here, we report a novel and interesting strategy by using the Drosha-mediated sgRNA-shRNA structure to direct Cas9 for multiplex genome targeting and precise genome editing. For multiplex genome targeting assay, we achieved more than 9% simultaneous mutant efficiency for 3 genomic loci among the puromycin-selected cell clones. By introducing the shRNA against DNA ligase IV gene (LIG4) into the sgRNA-shRNA construct, the HDR-based precise genome editing efficiency was improved as more than 2-fold. Our works provide a useful tool for multiplex and precise genome modifying in mammalian cells.

The research on upgrading and modification of the existing railway signal system found that the existing line basic datasheet and line data engineering datasheet cannot satisfy the application requirement, and it is necessary to study data optimization on the existing railway line. This paper presents a method for railway line data optimization and generation process verification. Based on the analysis of railway line data and the research of data update requirements, the hierarchical block storage model of line data is established by expanding the engineering datasheet, and design the data model generation process. The formal model of generation process is established by the model verification method combining UML with NuSMV model, which verifies the activity, certainty and transference of the important attributes in the model. The data model and generating process are improved by counterexample analysis to meet the requirements of signal system. The discussion of this paper provides useful solutions for the key problems encountered in the research and development of the existing railway signal system.

Railway ballast tamping operation is employed in order to restore the geometry of railway track distorted by train traffics. In this paper, based on analysis of tamping principle, the discrete element analysis model of railway ballast is created using the discrete element method, numerical simulations are performed to study the change of railway ballast compactness during tamping process. This paper presents the motion trend of stone ballasts as the change trend of railway ballast compactness in qualitative analysis, and the distance between stone ballast and sleeper as the change index of railway ballast compactness in quantitative analysis. By comparing simulation data of different vibration frequencies, an optimal vibration frequency is obtained. The simulation results accord with the actual industrial tamping operation, which verifies that the discrete element method is an effective method to evaluate the change of railway ballast compactness during tamping process.

The relationship between internet and human life is becoming much more close than ever before. At the same time, Modern enterprise cooperate with each other in the form of technical collaboration is becoming a common mode of production and will be a crucial mode in the future. With the rapid development and popularization of internet, the scope of collaboration is more and more wide, such as across the city, or even across the whole world are turning into reality. This paper gathered a set number of require-documents and provide-documents through a project. Due to the special content structure of require-documents and provide-documents, a require-document may be matched by some provide-documents, how to find a matching provide-documents for a require-document quickly and accurately and how to match a require-document for a provide-document are becoming the biggest problem. This paper proposes a require-documents and provide-documents matching algorithm based on topic model, and the algorithm relies on the text similarity. Finally, in this paper, the effect of the algorithm is verified.

SiRNA therapeutics promise a future where any target in the transcriptome could be potentially addressed. However, the delivery of SiRNAs and targeting of particular cell types or organs are major challenges. A novel, efficient, and safe delivery system for promising the introduction of SiRNAs into particular cell types within living organisms is of great significance. Our previous studies have proved that recombinant protein (MSTN) and exogenous gene (EGFP) as vaccines, and furthermore functional CD40 shRNA expression can be delivered into dendritic cells (DCs) in mouse by oral administration of recombinant yeast (Saccharomyces cerevisiae). Here, we describe the details of the promising and innovative approach based on oral administration of recombinant yeast that allows in vivo-targeted delivery of functional SiRNA to murine intestinal DCs.

SiRNA therapeutics promise a future where any target in the transcriptome could be potentially addressed. However, the delivery of SiRNAs and targeting of particular cell types or organs are major challenges. A novel, efficient, and safe delivery system for promising the introduction of SiRNAs into particular cell types within living organisms is of great significance. Our previous studies have proved that recombinant protein (MSTN) and exogenous gene (EGFP) as vaccines, and furthermore functional CD40 shRNA expression can be delivered into dendritic cells (DCs) in mouse by oral administration of recombinant yeast (Saccharomyces cerevisiae). Here, we describe the details of the promising and innovative approach based on oral administration of recombinant yeast that allows in vivo-targeted delivery of functional SiRNA to murine intestinal DCs.

Isolation of genetically modified cells generated by designed nucleases are challenging, since they are often phenotypically indistinguishable from their parental cells. To efficiently enrich genetically modified cells, we developed two dual-reporter surrogate systems, namely NHEJ-RPG and SSA-RPG based on NHEJ and SSA repair mechanisms, respectively. Repair and enrichment efficiencies of these two systems were compared using different nucleases. In both CRISPR-Cas9- and ZFNs-induced DSB repair studies, we found that the efficiency and sensitivity of the SSA-RPG reporter with direct repeat length more than 200 bp were much higher than the NHEJ-RPG reporter. By utilizing the SSA-RPG reporter, we achieved the enrichment for indels in several endogenous loci with 6.3- to 34.8-fold of non-selected cells. Thus, the highly sensitive SSA-RPG reporter can be used for activity validation of designed nucleases and efficient enrichment of genetically modified cells. Besides, our systems offer alternative enrichment choices either by puromycin selection or FACS.

The Streptococcus thermophilus CRISPR3-Cas (StCas9) system has been shown to mediate DNA cleavage in its original host and in E. coli as well as in vitro. Here, we have reconstituted the StCas9 system in yeast and conducted a systematic optimization of the sgRNA structure, including the minimal length of tracrRNA, loop structure, Match II region, Bulge motif, the minimal length of guide sequence within the crRNA, tolerance of mismatches and target sequence preference. The optimal sgRNA design for the StCas9 system achieved up to 12 and 40 % targeting efficiencies in yeast and human cells, respectively. This study provides important insight into the sequence and structural requirements necessary to develop a targeted and highly efficient eukaryotic gene editing platform using CRISPR-Cas systems.

The centerline segregation in the 82B steel billet reduces seriously the final product quality; it is closely related to the unreasonable secondary cooling water system. This paper has established a two-dimensional non-steady-state heat transfer model for the continuous 82B billet casting process, and optimized the existing secondary cooling water scheme, The results show that: the strand surface temperature falling rate is lower than the center temperature falling rate in the original cooling water scheme; it is necessary to add an additional cooling subzone after the fourth subzone for decreasing centerline segregation; the optimal cooling water scheme is that cooling intensity of the fifth subzone is increased by 150% compared with the original fourth subzone.

It is confirmed that the Chinese Train Control System (CTCS) level 3 system is adopted in newly-built railways where the train speed is expected to exceed 300 kilometers per hour. In order to construct the simulation and testing platform of the CTCS level 3 system, this paper focuses on the research of functional prototype of Radio Block Centre (RBC), including the following three key points. First, we find out functional requirements of RBC through a profound analysis of the CTCS level 3 system requirements. Then, we present the design of safety computer platform for RBC according to the safety requirements of train control equipments. Last, we design and accomplish the software of the RBC functional prototype on the base of the above achievements. Through the practical application in the simulation and testing platform of the newly-built railway, it is proved that the functional prototype accords with the CTCS level 3 system requirements specification and meets the construction requirements of the CTCS level 3 simulation and testing platform.

A fisheye camera calibration method is proposed by using two pairs of vanishing points from one single fisheye view in this paper. Aiming at a plane scene including two groups of parallel straight lines with different direction, one single fisheye image is viewed by a fisheye camera. Four vanishing points can be first computed by the intersection of the image line in the fisheye image. Since line segment joining a pair of vanishing points with same direction passes through the image center, the principal point is estimated by joining two pairs of vanishing point. Second, the focal length and aspect ratio may be obtained by using this property of two vanishing points corresponding one group parallel straight line. Last, we choose the estimated basic intrinsic parameters as an initial value, the fisheye lens distortion parameters may further be refined by minimizing the objective function from all fisheye image points on the same great circle. Experimental results demonstrate the validity of our method.

The problem of identifying spectra collected by large sky survey telescope is urgent to study to help astronomers discover new celestial bodies. Due to spectral data characteristics of high-dimension and volume, principle component analysis (PCA) technique is commonly used for extracting features and saving operations. Like many other matrix factorization methods, PCA lacks intuitive meaning because of its negativity. In this paper, non-negative matrix factorization (NMF) technique distinguished from PCA by its use of nonnegative constrains is applied to stellar spectral type classification. Firstly, NMF was used to extract features and compress data. Then an efficient classifier based on distance metric was designed to identify stellar types using the compressed data. The experiment results show that the proposed method has good performance over more than 70,000 real stellar data of Sloan Digital Sky Survey (SDSS). And the method is promising for large sky survey telescope projects.