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Yuan Z.,Peking Union Medical College | Zeng X.,Peking Union Medical College | Yang D.,Peking Union Medical College | Wang W.,Peking Union Medical College | And 3 more authors.
PLoS ONE | Year: 2013

Background:Emerging evidence suggests that single nucleotide polymorphisms (SNPs) in microRNA-coding genes may participate in the pathogenesis of lung cancer by altering the expression of tumor-related microRNAs. Several studies were investigated in recent years to evaluate the association between hsa-miR-196a2 rs11614913 polymorphism and increased/decreased lung cancer risk. In the present study, we performed a meta-analysis to systematically summarize the possible association.Methodology/Principal Findings:We performed a meta-analysis of 4 case-control studies that included 2219 lung-cancer cases and 2232 cancer-free controls. We evaluated the strength of the association using odds ratios (ORs) with 95% confidence intervals (CIs). In the overall analysis, it was found that the rs11614913 polymorphism significantly elevated the risk of lung cancer (CC versus (vs.) TT OR = 1.26, 95% CI 1.07-1.49, P = 0.007; CC/CT vs. TT: OR = 1.13, 95% CI 0.98-1.29, P = 0.007; C vs. T: OR = 1.12, 95% CI 1.03-1.22, P = 0.008). In the subgroup analysis by ethnicity, statistically significantly increased cancer risk was found among Asians (CC vs. TT: OR = 1.30, 95% CI 1.10-1.54, P = 0.003; CT vs. TT: OR = 1.16, 95% CI 1.01-1.34, P = 0.039; CC vs. CT/TT: OR = 1.21, 95% CI 1.04-1.41, P = 0.012; C vs. T: OR = 1.14, 95% CI 1.05-1.25, P = 0.002). For Europeans, a significant association with lung cancer risk was found in recessive model (CC vs. CT/TT: OR = 0.63, 95% CI 0.40-0.98, P = 0.040). No publication bias was found in this study.Conclusions/Significance:Our meta-analysis suggests that the rs11614913 polymorphism is significant associated with the increased risk of lung cancer, especially in Asians. Besides, the C allele of rs11614913 polymorphism may contribute to increased lung cancer risk. © 2013 Yuan et al.

Wang K.C.,Beijing Normal University | Dickinson R.E.,University of Texas at Austin | Su L.,Beijing City University | Trenberth K.E.,U.S. National Center for Atmospheric Research
Atmospheric Chemistry and Physics | Year: 2012

Atmospheric aerosols affect both human health and climate. PMX is the mass concentration of aerosol particles that have aerodynamic diameters less than X 1/4m, PM10 was initially selected to measure the environmental impact of aerosols. Recently, it was realized that fine particles are more hazardous than larger ones and should be measured. Consequently, observational data for PM2.5 have been obtained but only for a much shorter period than that of PM10. Optical extinction of aerosols, the inverse of meteorological visibility, is sensitive to particles less than 1.0 1/4m. These fine particles only account for a small part of total mass of aerosols although they are very efficient in light extinction. Comparisons are made between PM10 and PM2.5 over the period when the latter is available and with visibility data for a longer period. PM10 has decreased by 44% in Europe from 1992 to 2009, 33% in the US from 1993 to 2010, 10% in Canada from 1994 to 2009, and 26% in China from 2000 to 2011. However, in contrast, aerosol optical extinction has increased 7% in the US, 10% in Canada, and 18% in China during the above study periods. The reduction of optical extinction over Europe of 5% is also much less than the 44% reduction in PM10. Over its short period of record PM2.5 descreased less than PM10. Hence, PM10 is neither a good measure of changes in smaller particles nor of their long-term trends, a result that has important implications for both climate impact and human health effects. The increased fraction of anthropogenic aerosol emission, such as from vehicle exhaust, to total atmospheric aerosols partly explains this contrasting trend of optical and mass properties of aerosols.

Luo S.,CAS Institute of Remote Sensing | Luo S.,Beijing City University | Wang C.,CAS Institute of Remote Sensing | Xi X.,CAS Institute of Remote Sensing | Pan F.,University of North Texas
Optics Express | Year: 2014

The fraction of absorbed photosynthetically active radiation (FPAR) is a key parameter for ecosystem modeling, crop growth monitoring and yield prediction. Ground-based FPAR measurements are time consuming and labor intensive. Remote sensing provides an alternative method to obtain repeated, rapid and inexpensive estimates of FPAR over large areas. LiDAR is an active remote sensing technology and can be used to extract accurate canopy structure parameters. A method to estimating FPAR of maize from airborne discrete-return LiDAR data was developed and tested in this study. The raw LiDAR point clouds were processed to separate ground returns from vegetation returns using a filter method over a maize field in the Heihe River Basin, northwest China. The fractional cover (fCover) of maize canopy was computed using the ratio of canopy return counts or intensity sums to the total of returns or intensities. FPAR estimation models were established based on linear regression analysis between the LiDAR-derived fCover and the field-measured FPAR (R2 = 0.90, RMSE = 0.032, p < 0.001). The reliability of the constructed regression model was assessed using the leave-one-out cross-validation procedure and results show that the regression model is not overfitting the data and has a good generalization capability. Finally, 15 independent fieldmeasured FPARs were used to evaluate accuracy of the LiDAR-predicted FPARs and results show that the LiDAR-predicted FPAR has a high accuracy (R2 = 0.89, RMSE = 0.034). In summary, this study suggests that the airborne discrete-return LiDAR data could be adopted to accurately estimate FPAR of maize. © 2014 Optical Society of America.

Zhang Y.,Tianjin University | Zhu L.,Tianjin University | Lai Y.,Beijing City University
International Journal of Digital Content Technology and its Applications | Year: 2012

The main purpose of this paper is to build a system that can complete the whole process from collecting GPS data, transmitting through GSM network, processing GPS data, to displaying position in maps. Also, two further applications relied on this system is proposed in this paper. There are two modules in this system. One is GPSLogger, which can collect instant position data and transmit those data into the server, running on AVR Atmage64 microcontroller. The other one is GPSTracer that can gather GPS data from the logger calculate the geographic information and display position on the map.

Du W.,Beijing City University
Journal of Convergence Information Technology | Year: 2012

This study has built a scientific and reliable logistics simulation system. Grid management model which has advantage on the aspect of logistics resource allocation has been chosen to conduct the simulation study, and by building a comparison model between grid and non-grid logistics, the average waiting number, average demand, average waiting time, average time of stay and resource utilization rate during resource allocation are used as evaluation indices to conduct comparison and analysis. The result shows that the urban logistics resource integration system based on grid management can sweep away the barriers to solve various problems in urban logistics planning, such as integration and optimization of various resources, efficient utilization and collaboration.

Gao Q.,Beijing City University
Applied Mechanics and Materials | Year: 2013

This paper presented a kind of robot self-protection system which was a combination of photoelectric sensor and ultrasonic sensor. In this study, signals were gathered by using the complement of ranging of photoelectric sensor and ultrasonic sensor. Then the signals were sent to MCU to achieve multi-sensors information fusion.With such function, an accurate robot self-protection command was made as to avoid obstacles, to judge narrow highland and to prevent dropping. The experiment results validate its good self-protection function. © (2013) Trans Tech Publications, Switzerland.

Lin W.,Beijing City University
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2013

Buffer overflow attacks have been the most common form in the network attacks and become a predominant problem in the system and network security area. With specific programs, this paper describes in detail the type of buffer overflow attacks and technical principles, so we have a good understanding of them, and then gives several common preventive measures. © 2013 SPIE.

Dong X.,Beijing City University
Advanced Materials Research | Year: 2011

This paper will introduce the basic methods of soil-structure dynamic interaction at home and abroad, and analysis the advantages and disadvantages of these methods. Finally, the paper will put forward opinions on the research tendency of soil-structure dynamic interaction. With the development of urbanization, the urban population, planning area and urban environment are faced with tremendous stress, so developing and utilizing the underground space becomes the concerns of many cities. In recent decades, the underground structure has been widely used in urban construction, transportation, national defense engineering, and hydraulic engineering and so on. Especially in the urban construction, with underground railway which has been seemed as the large-capacity backbone and fast public transport system has become an important issue of urban passenger traffic solution. In our country, there are still large potential in developing and utilizing the underground structure and the structure forms will become more and more complicated. China is a strong and frequent earthquake country, the earthquake-proof problems about the underground structures such as Long-span subway station has become city astigmatic engineering and the important research content on disaster prevention and mitigation. These researches can ensure the safe use of underground structures and reduce natural disasters to humankind. To the subway station and the tunnel structure, soil characteristics significantly influence the structure seismic response and destruction features. In seismic response process, the overburden of gravitational can greatly affect on the structural seismic response. The solution to the underground structure seismic problem should focus on two aspects: on one hand we should focus on the research of soil-structure dynamic interaction; on the other hand, we should deal with soil's half-limitlessness simulation problem. © (2011) Trans Tech Publications, Switzerland.

Luo S.,Chinese Academy of Sciences | Luo S.,Beijing City University | Wang C.,Chinese Academy of Sciences | Li G.,National Satellite Meteorological Center | Xi X.,Chinese Academy of Sciences
Remote Sensing Letters | Year: 2013

Leaf area index (LAI) is an important parameter controlling many biological and physical processes associated with vegetation on the Earth's surface. In this study, an algorithm for estimating LAI from the ICESat (Ice, Cloud and land Elevation Satellite)/GLAS (Geoscience Laser Altimeter System) data was proposed and applied to a forest area in the Tibetan Plateau. First, Gaussian decomposition of the GLAS waveform was implemented to identify the ground peaks and calculate the ground and canopy return energy. Second, the ground-to-total energy ratio (Er) was computed as the ratio of the ground return energy to the total waveform return energy for each GLAS footprint. Third, a regression model between the Er and the field-measured LAI was established based on the Beer-Lambert law. The coefficient of determination (R2) of the model was 0.81 and the root mean square error (RMSE) is 0.35 (n = 23, p < 0.001). Finally, the leave-one-out cross-validation procedure was used to assess the constructed regression model. The results indicate that the regression model is not overfitting the data and has a good generalization capability. We validated the accuracy of the GLAS-predicted LAIs using the other 15 field-measured LAIs (R2 = 0.84), and the result shows that the accuracy of the GLAS-predicted LAI is high (RMSE = 0.31). © 2013 Taylor & Francis.

Feng X.-C.,Beijing City University
Applied Mechanics and Materials | Year: 2014

Cloud computing, the future development direction of the IT industry, has the profound influence of cloud computing applications, which is bound to the field of higher education, the construction of university network education resources platform is the integration of all kinds of educational resources of colleges and universities, and to provide fast and convenient resource storage, sharing, learning and computational ability. This article is from the university network education platform of cloud computing based on the advantages of the proposed strategy, construction of information resources of University under the cloud computing environment. This is how the cloud model construction resources platform of network education in Colleges and universities. With the rapid development of Internet, people from all walks of life to and gradually mature "cloud computing" model of combining the road to seek an opportunity. However, in the field of education, the application of cloud computing is scanty. Research on the current college network education situation and abuse with according to the characteristics of cloud computing, advantages, and puts forward the conception of network education platform based on cloud computing, and further demonstrates its feasibility. It is the high time to improve the transplantation and service application pattern of cloud computing in the field of education. The main works of this paper are as follows: firstly, the domestic and foreign network education to analyze the situation, reasons and problems existing in domestic university network education problems. © (2014) Trans Tech Publications, Switzerland.

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