To retrieve wind field from SAR images, the development for surface wind field retrieval from SAR images based on the improvement of new inversion model is present. Geophysical Model Functions （GMFs） have been widel...To retrieve wind field from SAR images, the development for surface wind field retrieval from SAR images based on the improvement of new inversion model is present. Geophysical Model Functions （GMFs） have been widely applied for wind field retrieval from SAR images. Among them CMOD4 has a good performance under low and moderate wind conditions. Although CMOD5 is developed recently with a more fundamental basis, it has ambiguity of wind speed and a shape gradient of normalized radar cross section under low wind speed condition. This study proposes a method of wind field retrieval from SAR image by com-bining CMOD5 and CMOD4 Five VV-polarisation RADARSAT2 SAR images are implemented for validation and the retrieval re-suits by a combination method （CMOD5 and CMOD4） together with CMOD4 GMF are compared with QuikSCAT wind data. The root-mean-square error （RMSE） of wind speed is 0.75 m s-1 with correlation coefficient 0.84 using the combination method and the RMSE of wind speed is 1.01 m s-1 with correlation coefficient 0.72 using CMOD4 GMF alone for those cases. The proposed method can be applied to SAR image for avoiding the internal defect in CMOD5 under low wind speed condition.展开更多
One new and two known species of the subgenus Stegana(s.str.)from China are described or redescribed:S.(S.)helvipecta sp.nov.,S.(S.)furta(Linnaeus,1767)and S.(S.)taba Okada,1971.A total of 41 DNA sequences of partial ...One new and two known species of the subgenus Stegana(s.str.)from China are described or redescribed:S.(S.)helvipecta sp.nov.,S.(S.)furta(Linnaeus,1767)and S.(S.)taba Okada,1971.A total of 41 DNA sequences of partial mitochondrial cytochrome c oxidase subunit I(COI)gene of 18 species of this subgenus are newly obtained in this study.These sequences along with other available barcoding sequences for this subgenus are incorporated in a molecular analysis using the neighbor-joining(NJ)method in order to assess the efficacy of DNA barcoding for delimiting these species.Habitus and a key to all Chinese Stegana(s.str.)species are provided.展开更多
In Pakistan more than 10 million people are living with Hepatitis C virus (HCV), with high morbidity and mortality. This article reviews the prevalence, genotypes and factors associated with HCV infection in the Pakis...In Pakistan more than 10 million people are living with Hepatitis C virus (HCV), with high morbidity and mortality. This article reviews the prevalence, genotypes and factors associated with HCV infection in the Pakistani population. A literature search was performed by using the keywords; HCV prevalence, genotypes and risk factors in a Pakistani population, in Pubmed, PakMediNet and Google scholar. Ninetyone different studies dating from 1994 to May 2009 were included in this study, and weighted mean and standard error of each population group was calculated. Percentage prevalence of HCV was 4.95% ± 0.53% in the general adult population, 1.72% ± 0.24% in the pediatric population and 3.64% ± 0.31% in a young population applying for recruitment, whereas a very high 57% ± 17.7% prevalence was observed in injecting drug users and 48.67% ± 1.75% in a multi-transfused population. Most prevalent genotype of HCV was 3a. HCV prevalence was moderate in the general population but very high in injecting drug users and multi-transfused populations. This data suggests that the major contributing factors towards increased HCV prevalence include unchecked blood transfusions and reuse of injection syringes. Awareness programs are required to decrease the future burden of HCV in the Pakistani population.展开更多
基金supported by the National Natural Science Foundation of China (Nos.41376010 and 40830959)the Start-up Foundation of Zhejiang Ocean University (No.21105011913)
文摘To retrieve wind field from SAR images, the development for surface wind field retrieval from SAR images based on the improvement of new inversion model is present. Geophysical Model Functions （GMFs） have been widely applied for wind field retrieval from SAR images. Among them CMOD4 has a good performance under low and moderate wind conditions. Although CMOD5 is developed recently with a more fundamental basis, it has ambiguity of wind speed and a shape gradient of normalized radar cross section under low wind speed condition. This study proposes a method of wind field retrieval from SAR image by com-bining CMOD5 and CMOD4 Five VV-polarisation RADARSAT2 SAR images are implemented for validation and the retrieval re-suits by a combination method （CMOD5 and CMOD4） together with CMOD4 GMF are compared with QuikSCAT wind data. The root-mean-square error （RMSE） of wind speed is 0.75 m s-1 with correlation coefficient 0.84 using the combination method and the RMSE of wind speed is 1.01 m s-1 with correlation coefficient 0.72 using CMOD4 GMF alone for those cases. The proposed method can be applied to SAR image for avoiding the internal defect in CMOD5 under low wind speed condition.
基金supported by the National Natural Science Foundation of China(31672321,31093430)。
文摘One new and two known species of the subgenus Stegana(s.str.)from China are described or redescribed:S.(S.)helvipecta sp.nov.,S.(S.)furta(Linnaeus,1767)and S.(S.)taba Okada,1971.A total of 41 DNA sequences of partial mitochondrial cytochrome c oxidase subunit I(COI)gene of 18 species of this subgenus are newly obtained in this study.These sequences along with other available barcoding sequences for this subgenus are incorporated in a molecular analysis using the neighbor-joining(NJ)method in order to assess the efficacy of DNA barcoding for delimiting these species.Habitus and a key to all Chinese Stegana(s.str.)species are provided.
基金Supported by Higher Education Commission of Pakistan Grant No.829Pak-US Science and Technology Cooperative Program,entitled "HCV management in Pakistan"
文摘In Pakistan more than 10 million people are living with Hepatitis C virus (HCV), with high morbidity and mortality. This article reviews the prevalence, genotypes and factors associated with HCV infection in the Pakistani population. A literature search was performed by using the keywords; HCV prevalence, genotypes and risk factors in a Pakistani population, in Pubmed, PakMediNet and Google scholar. Ninetyone different studies dating from 1994 to May 2009 were included in this study, and weighted mean and standard error of each population group was calculated. Percentage prevalence of HCV was 4.95% ± 0.53% in the general adult population, 1.72% ± 0.24% in the pediatric population and 3.64% ± 0.31% in a young population applying for recruitment, whereas a very high 57% ± 17.7% prevalence was observed in injecting drug users and 48.67% ± 1.75% in a multi-transfused population. Most prevalent genotype of HCV was 3a. HCV prevalence was moderate in the general population but very high in injecting drug users and multi-transfused populations. This data suggests that the major contributing factors towards increased HCV prevalence include unchecked blood transfusions and reuse of injection syringes. Awareness programs are required to decrease the future burden of HCV in the Pakistani population.
