Strategic Environmental Policy and Environmental Tariffs

( Yu Qing Xing ) 세종대학교 경제통합연구소 (구 세종대학교 국제경제연구소) 2006 Journal of Economic Integration Vol.21 No.4

This paper uses a three-stage game to analyze how environmental tariffs affect the strategic behavior of a government in designing environmental policy. The game is based on an international duopoly model with detrimental externality in production and asymmetric environmental policies between two countries. It shows that the welfare effect of the foreign country`s strategic environmental policy on the home country is ambiguous. In the circumstance that the home country would be worse off due to the lenient environmental policy of the foreign country, there exists an optimal environmental tariff. If the home country imposes the optimal tariff on the pollution-intensive imports, any deviation from the first best environmental policy by the foreign country would make the home country better off. In addition, the implementation of the environmental tariff would mitigate the motivation of the foreign country to pursue strategic environmental policy, and drive the lenient environmental standard toward the efficient level. The theoretical results imply that, in an open economy with non-harmonized environmental standards, imposing environmental tariffs on imports from the countries with lax environmental regulations would correct the adverse welfare effect, and more importantly induce the upward harmonization on environmental policy across countries.

Sublethal effects of beta-cypermethrin on the bird cherry-oat aphid Rhopalosiphum padi (Hemiptera: Aphididae)

Qing-Qing Zhang,Wen-Qiang Li,Zeng-Bin Lu,Li-Li Li,Yi Yu,Chao Li,Xing-Yuan Men 한국응용곤충학회 2019 Journal of Asia-Pacific Entomology Vol.22 No.3

Rhopalosiphum padi is a sap-sucking aphid and an important pest of wheat that causes considerable yield loss. Beta-cypermethrin, a synthetic pyrethroid pesticide, has a broad insecticide spectrum and is considered effective for aphid control, while its residual concentrations may have sublethal effects on R. padi. Here, the sublethal effects of beta-cypermethrin on R. padi were conducted under laboratory conditions. The acute toxicity test showed that LC 10 , LC 20 , and LC 25 of beta-cypermethrin to R. padi adults were 0.003, 0.031 and 0.079 mg L −1 , respectively. The pre-adult survival rate was significantly reduced by all three concentrations. LC 20 significantly extended the development duration of 1st instar nymphs, pre-oviposition period, and oviposition period of R. padi. The adult longevity was also reduced by LC 25 . However, the fecundity did not differ between the betacypermethrin treatment and control. For life table parameters, both the finite rate (λ) and intrinsic rate of increase (r) decreased at LC 10 and LC 20 , as well as the net reproductive rate (R 0 ) reduced at LC 10 and LC 25 , while mean generation time (T) increased at LC 20 . Thus, at the concentrations of beta-cypermethrin tested here, there were negative impacts on R. padi fitness by decreased pre-adult survival rate, λ, r, and R 0 , and delayed the development of some stages and increased T.

Reference gene selection for transcriptional profiling by RT-qPCR in the 28-spotted larger potato ladybird

Zhang Yu-Xing,Tan Qiao,Shen Chen-Hui,Wu Jian-Jian,Wu Yi-Kuan,Li Wen-Ze,Jin Lin,Li Guo-Qing 한국응용곤충학회 2022 Journal of Asia-Pacific Entomology Vol.25 No.2

Henosepilachna vigintioctomaculata is one of the most serious defoliates attacking potatoes. However, studies on functional genes have greatly been limited due to the insufficiency of effective and stable endogenous references to normalize RT-qPCR data. In this report, nine housekeeping genes (RPL4, RPL6, RPL13, RPL32, RPS18, ACT, EF1α, GAPDH and α-TUB) involved in different biological processes were selected. Their expression levels under diverse experimental conditions including developmental stages, tissues, temperatures and host plants were determined using RT-qPCR technology. The tested candidate genes were comprehensively ranked based on five alternative stability analysis methods (Ct value, geNorm, NormFinder, BestKeeper and ReFinder). The results revealed that the optimal internal reference genes varied under different experimental conditions. Any gene pair among the five candidates (RPL4, RPL13, RPL32, RPS18 and EF1α) was a suitable reference gene set under different temperatures and on different host plants. A combination of RPL6 and RPL13 was recommended as the best reference gene set across different developmental stages. A pair of RPS18 and EF1α was ranked as the optimal reference gene combination within different tissues. The most suitable reference genes were RPS18 and RPL13 under four different experimental conditions. Our findings not only establish an accurate and reliable normalization of RT-qPCR data, but also lay a solid foundation for further functional gene researches in H. vigintioctomaculata

Rapid and Efficient Detection of 16SrI Group Areca Palm Yellow Leaf Phytoplasma in China by Loop-Mediated Isothermal Amplification

Shao-shuai Yu,Hai-yan Che,Sheng-jie Wang,Cai-li Lin,Ming-xing Lin,Wei-wei Song,Qing-hua Tang,Wei Yan,Wei-quan Qin 한국식물병리학회 2020 Plant Pathology Journal Vol.36 No.5

Areca palm yellow leaf (AYL) disease caused by the 16SrI group phytoplasma is a serious threat to the development of the Areca palm industry in China. The 16S rRNA gene sequence was utilized to establish a rapid and efficient detection system efficient for the 16SrI-B subgroup AYL phytoplasma in China by loopmediated isothermal amplification (LAMP). The results showed that two sets of LAMP detection primers, 16SrDNA-2 and 16SrDNA-3, were efficient for 16SrIB subgroup AYL phytoplasma in China, with positive results appearing under reaction conditions of 64oC for 40 min. The lowest detection limit for the two LAMP detection assays was the same at 200 ag/μl, namely approximately 53 copies/μl of the target fragments. Phytoplasma was detected in all AYL disease samples from Baoting, Tunchang, and Wanning counties in Hainan province using the two sets of LAMP primers 16SrDNA-2 and 16SrDNA-3, whereas no phytoplasma was detected in the negative control. The LAMP method established in this study with comparatively high sensitivity and stability, provides reliable results that could be visually detected, making it suitable for application and research in rapid diagnosis of AYL disease, detection of seedlings with the pathogen and breeding of diseaseresistant Areca palm varieties.

Two Androstane Derivatives from the Cultures of Fungus Marasmiellus ramealis (Bull.) Singer

Ning-Ning Yang,Qing-Yun Ma,Sheng-Zhuo Huang,Hao-Fu Dai,Zhi-Kai Guo,Zhi-Fang Yu,You-Xing Zhao 대한화학회 2014 Bulletin of the Korean Chemical Society Vol.35 No.11

A new androstane derivative, 4β-methyl-15-oxa-14β-androstane-7-ene-4α-carboxylic acid (1) and a known one 4β-methyl-15-oxa-14β-androstane-7-ene-4α-hydroxyl (2) were isolated from the EtOAc extract of the cultures of the fungus Marasmiellus ramealis (Bull.) Singer. Their structures were elucidated on the basis of 1D and 2D NMR as well as MS spectroscopic data analysis. The inhibitory activity of two isolates against acetylcholinesterase (AChE) revealed that compound 1 exhibited definitely inhibitory activity.

Ginsengenin derivatives synthesized from 20(R)-panaxotriol: Synthesis, characterization, and antitumor activity targeting HIF-1 pathway

Guo, Hong-Yan,Xing, Yue,Sun, Yu-Qiao,Liu, Can,Xu, Qian,Shang, Fan-Fan,Zhang, Run-Hui,Jin, Xue-Jun,Chen, Fener,Lee, Jung Joon,Kang, Dongzhou,Shen, Qing-Kun,Quan, Zhe-Shan The Korean Society of Ginseng 2022 Journal of Ginseng Research Vol.46 No.6

Background: Ginseng possesses antitumor effects, and ginsenosides are considered to be one of its main active chemical components. Ginsenosides can further be hydrolyzed to generate secondary saponins, and 20(R)-panaxotriol is an important sapogenin of ginsenosides. We aimed to synthesize a new ginsengenin derivative from 20(R)-panaxotriol and investigate its antitumor activity in vivo and in vitro. Methods: Here, 20(R)-panaxotriol was selected as a precursor and was modified into its derivatives. The new products were characterized by ¹H-NMR, ¹³C-NMR and HR-MS and evaluated by molecular docking, MTT, luciferase reporter assay, western blotting, immunofluorescent staining, colony formation assay, EdU labeling and immunofluorescence, apoptosis assay, cells migration assay, transwell assay and in vivo antitumor activity assay. Results: The derivative with the best antitumor activity was identified as 6,12-dihydroxy-4,4,8,10,14-pentamethyl-17-(2,6,6-trimethyltetrahydro-2H-pyran-2-yl)hexadecahydro-1H-cyclopenta[a]phenanthren-3-yl(tert-butoxycarbonyl)glycinate (A11). The focus of this research was on the antitumor activity of the derivatives. The efficacy of the derivative A11 (IC₅₀ < 0.3 µM) was more than 100 times higher than that of 20(R)- panaxotriol (IC₅₀ > 30 µM). In addition, A11 inhibited the protein expression and nuclear accumulation of the hypoxia-inducible factor HIF-1α in HeLa cells under hypoxic conditions in a dose-dependent manner. Moreover, A11 dose-dependently inhibited the proliferation, migration, and invasion of HeLa cells, while promoting their apoptosis. Notably, the inhibition by A11 was more significant than that by 20(R)-panaxotriol (p < 0.01) in vivo. Conclusion: To our knowledge, this is the first study to report the production of derivative A11 from 20(R)-panaxotriol and its superior antitumor activity compared to its precursor. Moreover, derivative A11 can be used to further study and develop novel antitumor drugs.

Expression and Significance of Twist and E-cadherin in Ovarian Cancer Tissues

Wang, Wen-Shuang,Yu, Shou-Li,Yang, Xing-Sheng,Chang, Shu-De,Hou, Jian-Qing Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.2

Objective: To investigate the expression of Twist and E-cadherin in ovarian cancer tissues as well as the role of epithelial-mesenchymal transformation (EMT) in ovarian cancer metastasis. Method: The expressions of Twist and E-cadherin in 54 cases of ovarian cancer and paracancerous tissues were detected by Western blottin g and reverse transcriptase polymerase chain reaction. We used RNA interference to silence Twist expression in human ovarian cancer cell line, and detected E-cadherin expression using Western blotting. Results: There was an increase in the relative abundance of Twist proteins and a decrease in E-cadherin in ovarian cancer compared with normal ovary tissues (P < 0.05). The expression levels of Twist and E-cadherin mRNA were $1.49{\pm}0.53$ and $0.82{\pm}0.24$ in ovarian cancer, and $1.14{\pm}0.38$ and $1.08{\pm}0.19$ in paracancerous tissues, respectively. The difference between the indicators in ovarian cancer and in paracancerous tissues was statistically significant (P < 0.05). When the Twist expression was silenced in an ovarian cancer cell line, the expression of the E-cadherin protein increased (P<0.05). Conclusion: The expression of Twist is upregulated, whereas that of E-cadherin is downregulated in ovarian cancer. EMT, mediated by Twist, may be correlated with ovarian cancer metastasis.

Two Androstane Derivatives from the Cultures of Fungus Marasmiellus ramealis (Bull.) Singer

Yang, Ning-Ning,Ma, Qing-Yun,Huang, Sheng-Zhuo,Dai, Hao-Fu,Guo, Zhi-Kai,Yu, Zhi-Fang,Zhao, You-Xing Korean Chemical Society 2014 Bulletin of the Korean Chemical Society Vol.35 No.11

A new androstane derivative, $4{\beta}$-methyl-15-oxa-$14{\beta}$-androstane-7-ene-$4{\alpha}$-carboxylic acid (1) and a known one $4{\beta}$-methyl-15-oxa-$14{\beta}$-androstane-7-ene-$4{\alpha}$-hydroxyl (2) were isolated from the EtOAc extract of the cultures of the fungus Marasmiellus ramealis (Bull.) Singer. Their structures were elucidated on the basis of 1D and 2D NMR as well as MS spectroscopic data analysis. The inhibitory activity of two isolates against acetylcholinesterase (AChE) revealed that compound 1 exhibited definitely inhibitory activity.

Fibulin2: a negative regulator of BMSC osteogenic differentiation in infected bone fracture healing

Li Shi-Dan,Xing Wei,Wang Shao-Chuan,Li You-Bin,Jiang Hao,Zheng Han-Xuan,Li Xiao-Ming,Yang Jing,Guo De-Bin,Xie Xiao-Yu,Jiang Ren-Qing,Fan Chao,Li Lei,Xu Xiang,Fei Jun 생화학분자생물학회 2023 Experimental and molecular medicine Vol.55 No.-

Bone fracture remains a common occurrence, with a population-weighted incidence of approximately 3.21 per 1000. In addition, approximately 2% to 50% of patients with skeletal fractures will develop an infection, one of the causes of disordered bone healing. Dysfunction of bone marrow mesenchymal stem cells (BMSCs) plays a key role in disordered bone repair. However, the specific mechanisms underlying BMSC dysfunction caused by bone infection are largely unknown. In this study, we discovered that Fibulin2 expression was upregulated in infected bone tissues and that BMSCs were the source of infection-induced Fibulin2. Importantly, Fibulin2 knockout accelerated mineralized bone formation during skeletal development and inhibited inflammatory bone resorption. We demonstrated that Fibulin2 suppressed BMSC osteogenic differentiation by binding to Notch2 and inactivating the Notch2 signaling pathway. Moreover, Fibulin2 knockdown restored Notch2 pathway activation and promoted BMSC osteogenesis; these outcomes were abolished by DAPT, a Notch inhibitor. Furthermore, transplanted Fibulin2 knockdown BMSCs displayed better bone repair potential in vivo. Altogether, Fibulin2 is a negative regulator of BMSC osteogenic differentiation that inhibits osteogenesis by inactivating the Notch2 signaling pathway in infected bone.

Two New Phenolic Glycosides from Hypoxis aurea Lour

Cheng, Zhong-Quan,Yang, Dan,Liu, Yu-Qing,Hu, Jiang-Miao,Jiang, He-Zhong,Wang, Peng-Cheng,Li, Ning,Zhou, Jun,Zhao, You-Xing Korean Chemical Society 2009 Bulletin of the Korean Chemical Society Vol.30 No.10