Subspecific Status of the Korean Tiger Inferred by Ancient DNA Analysis

Mu-Yeong Lee,Jee Yun Hyun,Seo-Jin Lee,Junghwa An,Eunok Lee,Mi-Sook Min,Junpei Kimura,Shin-ichiro Kawada,Nozomi Kurihara,Shu-Jin Luo,Stephen J. O’Brien,Warren E. Johnson,Hang Lee 한국동물분류학회 2012 Animal Systematics, Evolution and Diversity Vol.28 No.1

The tiger population that once inhabited the Korean peninsula was initially considered a unique subspecies (Panthera tigris coreensis), distinct from the Amur tiger of the Russian Far East (P. t. altaica). However, in the following decades, the population of P. t. coreensis was classified as P. t. altaica and hence forth the two populations have been considered the same subspecies. From an ecological point of view, the classification of the Korean tiger population as P. t. altaica is a plausible conclusion. Historically, there were no major dispersal barriers between the Korean peninsula and the habitat of Amur tigers in Far Eastern Russia and northeastern China that might prevent gene flow, especially for a large carnivore with long-distance dispersal abilities. However, there has yet to be a genetic study to confirm the subspecific status of the Korean tiger. Bone samples from four tigers originally caught in the Korean peninsula were collected from two museums in Japan and the United States. Eight mitochondrial gene fragments were sequenced and compared to previously published tiger subspecies’ mtDNA sequences to assess the phylogenetic relationship of the Korean tiger. Three individuals shared an identical haplotype with the Amur tigers. One specimen grouped with Malayan tigers, perhaps due to misidentification or mislabeling of the sample. Our results support the conclusion that the Korean tiger should be classified as P. t. altaica, which has important implications for the conservation and reintroduction of Korean tigers.

New triterpenoids from Staphylea bumalda flower buds and their neuroprotective activity against H2O2-induced injury in vitro

Zheng-Xi Zhang,Kun Feng,Xian-Jin Sui,Wen-Shu Wang,Lin Wang,Dong-Hong Wang,Xiao-Min Luo,Xiao-Fei Chen 대한약학회 2018 Archives of Pharmacal Research Vol.41 No.12

Four new acylated triterpene glycosides with aliphatic chains (4–7) as well as five known triterpenoids were isolated from the flower buds of Staphylea bumalda with bioassay guidance. Their structures were determined on the basis of spectral techniques, including IR, 1D and 2D NMR, and HR-APCI-MS. Most compounds (except 8) were isolated from S. bumalda for the first time. Additionally, the neuroprotective effects of 1 and 4–9 on suckling rat primary cultured hippocampal neurons against H2O2-induced injury were evaluated in vitro. The four new triterpenoids (4–7) showed neuroprotective effects, which increased the cell viability to over 74% at different concentrations, which was higher than the negative control (59%), while compounds 1 and 8–9 exhibited cytotoxic activity.

The Effect of Transformation on the Virulence of Streptococcus pneumoniae

Xue-Mei Zhang,Yi-Bing Yin,Dan Zhu,Bao-De Chen,Jin-Yong Luo,Yi-Ping Deng,Ming-Fang Liu,Shu-Hui Chen,Jiang-Ping Meng,Kai Lan,Yuan-Shuai Huang,Ge-Fei Kang 한국미생물학회 2005 The journal of microbiology Vol.43 No.4

Although pneumococcus is one of the most frequently encountered opportunistic pathogen in the world, the mechanisms responsible for its infectiveness have not yet been fully understood. In this paper, we have attempted to characterize the effects of pneumococcal transformation on the pathogenesis of the organism. We constructed three transformation-deficient pneumococcal strains, which were designated as Nos. 1d, 2d, and 22d. The construction of these altered strains was achieved via the insertion of the inactivated gene, comE, to strains 1, 2 and 22. We then conducted a comparison between the virulence of the transformation-deficient strains and that of the wild-type strains, via an evaluation of the ability of each strain to adhere to endothelial cells, and also assessed psaA mRNA expression, and the survival of hosts after bacterial challenge. Compared to what was observed with the wild-type strains, our results indicated that the ability of all of the transformation-deficient strains to adhere to the ECV304 cells had been significantly reduced (p < 0.05), the expression of psaA mRNA was reduced significantly (p < 0.05) in strains 2d and 22d, and the median survival time of mice infected with strains 1d and 2d was increased significantly after intraperitoneal bacterial challenge (p < 0.05). The results of our study also clearly indicated that transformation exerts significant effects on the virulence characteristics of S. pneumoniae, although the degree to which this effect is noted appears to depend primarily on the genetic background of the bacteria.

Subspecific Status of the Korean Tiger Inferred by Ancient DNA Analysis

Lee, Mu-Yeong,Hyun, Jee-Yun,Lee, Seo-Jin,An, Jung-Hwa,Lee, Eun-Ok,Min, Mi-Sook,Kimura, Junpei,Kawada, Shin-Ichiro,Kurihara, Nozomi,Luo, Shu-Jin,O'Brien, Stephen J.,Johnson, Warren E.,Lee, Hang The Korean Society of Systematic Zoology 2012 Animal Systematics, Evolution and Diversity Vol.28 No.1

The tiger population that once inhabited the Korean peninsula was initially considered a unique subspecies (Panthera tigris coreensis), distinct from the Amur tiger of the Russian Far East (P. t. altaica). However, in the following decades, the population of P. t. coreensis was classified as P. t. altaica and hence forth the two populations have been considered the same subspecies. From an ecological point of view, the classification of the Korean tiger population as P. t. altaica is a plausible conclusion. Historically, there were no major dispersal barriers between the Korean peninsula and the habitat of Amur tigers in Far Eastern Russia and northeastern China that might prevent gene flow, especially for a large carnivore with long-distance dispersal abilities. However, there has yet to be a genetic study to confirm the subspecific status of the Korean tiger. Bone samples from four tigers originally caught in the Korean peninsula were collected from two museums in Japan and the United States. Eight mitochondrial gene fragments were sequenced and compared to previously published tiger subspecies' mtDNA sequences to assess the phylogenetic relationship of the Korean tiger. Three individuals shared an identical haplotype with the Amur tigers. One specimen grouped with Malayan tigers, perhaps due to misidentification or mislabeling of the sample. Our results support the conclusion that the Korean tiger should be classified as P. t. altaica, which has important implications for the conservation and reintroduction of Korean tigers.

The Effect of Transformation on the Virulence of Streptococcus pneumoniae

Zhang Xue-Mei,Yin Yi-Bing,Zhu Dan,Chen Bao-De,Luo Jin-Yong,Deng Vi-Ping,Liu Ming-Fang,Chen Shu-Hui,Meng Jiang-Ping,Lan Kai,Huang Yuan-Shuai,Kang Ge-Fei The Microbiological Society of Korea 2005 The journal of microbiology Vol.43 No.4

Although pneumococcus is one of the most frequently encountered opportunistic pathogen in the world, the mechanisms responsible for its infectiveness have not yet been fully understood. In this paper, we have attempted to characterize the effects of pneumococcal transformation on the pathogenesis of the organism. We constructed three transformation-deficient pneumococcal strains, which were designated as Nos. 1d, 2d, and 22d. The construction of these altered strains was achieved via the insertion of the inactivated gene, comE, to strains 1, 2 and 22. We then conducted a comparison between the virulence of the transformation-deficient strains and that of the wild-type strains, via an evaluation of the ability of each strain to adhere to endothelial cells, and also assessed psaA mRNA expression, and the survival of hosts after bacterial challenge. Compared to what was observed with the wild-type strains, our results indicated that the ability of all of the transformation-deficient strains to adhere to the ECV304 cells had been significantly reduced (p < 0.05), the expression of psaA mRNA was reduced significantly (p < 0.05) in strains 2d and 22d, and the median survival time of mice infected with strains Id and 2d was increased significantly after intraperitoneal bacterial challenge (p < 0.05). The results of our study also clearly indicated that transformation exerts significant effects on the virulence characteristics of S. pneumoniae, although the degree to which this effect is noted appears to depend primarily on the genetic background of the bacteria.

Guided waves of porous FG nanoplates with four edges clamped

Zhao, Jing-Lei,She, Gui-Lin,Wu, Fei,Yuan, Shu-Jin,Bai, Ru-Qing,Pu, Hua-Yan,Wang, Shilong,Luo, Jun Techno-Press 2022 Advances in nano research Vol.13 No.5

Based on the nonlocal strain gradient (NSG) theory and considering the influence of moment of inertia, the governing equations of motion of porous functionally graded (FG) nanoplates with four edges clamped are established; The Galerkin method is applied to eliminate the spatial variables of the partial differential equation, and the partial differential governing equation is transformed into an ordinary differential equation with time variables. By satisfying the boundary conditions and solving the characteristic equation, the dispersion relations of the porous FG strain gradient nanoplates with four edges fixed are obtained. It is found that when the wave number is very small, the influences of nonlocal parameters and strain gradient parameters on the dispersion relation is very small. However, when the wave number is large, it has a great influence on the group velocity and phase velocity. The nonlocal parameter represents the effect of stiffness softening, and the strain gradient parameter represents the effect of stiffness strengthening. In addition, we also study the influence of power law index parameter and porosity on guided wave propagation.