World Markets of Vertically Differentiated Agricultural Commodities: A Case of Soybean Markets

Replaced with revised version of poster 07/21/11.vertical product differentiation, market power, GM, non-GM, soybean, Industrial Organization, International Relations/Trade, L1,

Measuring Bilateral Market Power in International Markets of Vertically Differentiated Agricultural Commodities

Citation: Yamaura, K., & Xia, T. (2016). Measuring Bilateral Market Power in International Markets of Vertically Differentiated Agricultural Commodities. Journal of Agricultural and Food Industrial Organization, 14(1), 33-42. doi:10.1515/jafio-2013-0020Two features of international markets of agricultural commodities are bilateral market power of exporting and importing countries and the coexistence of non-genetically modified (non-GM) and genetically modified (GM) products. The two features were not taken into account in most extant studies on market power in international agricultural commodity markets. This research develops a bilateral oligopoly model with the interaction between non-GM and GM commodity and conducts an empirical estimation for U.S.-Japan soybean trade. The estimation results show that U.S. exporters and Japanese importers are almost equally sharing the dominance of market power. The analysis in this research provides new measures of market power and improves the understanding on world soybean markets. © 2016 by De Gruyter 2016

Effect of enhanced expression of connexin 43 on sunitinib-induced cytotoxicity in mesothelioma cells

AbstractConnexin (Cx) makes up a type of intercellular channel called gap junction (GJ). GJ plays a regulatory role in cellular physiology. The Cx expression level is often decreased in cancer cells compared to that in healthy ones, and the restoration of its expression has been shown to exert antiproliferative effects. This work aims to evaluate the effect of the restoration of connexin 43 (Cx43) (the most ubiquitous Cx subtype) expression on sunitinib (SU)-induced cytotoxicity in malignant mesothelioma (MM) cells. Increased Cx43 expression in an MM cell line (H28) improved the ability of SU to inhibit receptor tyrosine kinase (RTK) signaling. Moreover, higher Cx43 expression promoted SU-induced apoptosis. The cell viability test revealed that Cx43 enhanced the cytotoxic effect of SU in a GJ-independent manner. The effect of Cx43 on a proapoptotic factor, Bax, was then investigated. The interaction between Cx43 and Bax was confirmed by immunoprecipitation. Furthermore, higher Cx43 expression increased the production of a cleaved (active) form of Bax during SU-induced apoptosis with no alteration in total Bax expression. These findings indicate that Cx43 most likely increases sensitivity to SU in H28 through direct interaction with Bax. In conclusion, we found that Cx43 overcame the chemoresistance of MM cells

Changes in the expression of miRNAs at the pericentral and periportal regions of the rat liver in response to hepatocellular injury: comparison with the changes in the expression of plasma miRNAs

MicroRNAs (miRNAs) in body fluids have received attention as potential biomarkers of organ damage because miRNAs that are highly or specifically expressed in a given organ are likely released into body fluids as a result of damage to that organ. We previously determined that the plasma miRNA profile in rats was dramatically changed due to acetaminophen (APAP)-induced pericentral necrosis and methapyrilene (MP)-induced periportal necrosis in the liver. The purpose of this study was to examine whether the expression of hepatic miRNAs is differentially modulated at different zones due to injury and to examine the relationship of the hepatic miRNA profile with the changes in the plasma miRNA expression profile. Through the laser microdissection of the periportal and periportal regions of the liver and TaqMan microRNA Array analysis, we found that 49 miRNAs are differentially expressed between the pericentral and periportal regions of control rats. In both APAP- and MP-treated rats, the miRNAs that presented decreased expression dominated in both the injured and non-injured areas compared with the miRNAs that exhibited increased expression. The changes in miRNA expression in each region of the liver were compared with those observed in the plasma. Of the 301 plasma miRNAs with expression that was changed as a result of APAP administration, only 21% were changed in the injured area of the liver. Of the 263 plasma miRNAs with expression that was changed due to MP administration, only 24% were changed in the injured area of the liver. Thus, the miRNA expression profiles in the plasma do not merely reflect the release of miRNAs from the damaged cells in the liver. This report provides the first demonstration of zonal miRNA expression in the liver and of the relationship of the miRNA expression profile in a tissue with the plasma miRNA profile. © 2014 Elsevier Ireland Ltd

Plasma MicroRNA Profiles in Rat Models of Hepatocellular Injury, Cholestasis, and Steatosis

MicroRNAs (miRNAs) are small RNA molecules that function to modulate the expression of target genes, playing important roles in a wide range of physiological and pathological processes. The miRNAs in body fluids have received considerable attention as potential biomarkers of various diseases. In this study, we compared the changes of the plasma miRNA expressions by acute liver injury (hepatocellular injury or cholestasis) and chronic liver injury (steatosis, steatohepatitis and fibrosis) using rat models made by the administration of chemicals or special diets. Using miRNA array analysis, we found that the levels of a large number of miRNAs (121–317 miRNAs) were increased over 2-fold and the levels of a small number of miRNAs (6–35 miRNAs) were decreased below 0.5-fold in all models except in a model of cholestasis caused by bile duct ligation. Interestingly, the expression profiles were different between the models, and the hierarchical clustering analysis discriminated between the acute and chronic liver injuries. In addition, miRNAs whose expressions were typically changed in each type of liver injury could be specified. It is notable that, in acute liver injury models, the plasma level of miR-122, the most abundant miRNA in the liver, was more quickly and dramatically increased than the plasma aminotransferase level, reflecting the extent of hepatocellular injury. This study demonstrated that the plasma miRNA profiles could reflect the types of liver injury (e.g. acute/chronic liver injury or hepatocellular injury/cholestasis/steatosis/steatohepatitis/fibrosis) and identified the miRNAs that could be specific and sensitive biomarkers of liver injury

Market Power of The Japanese Non-GM Soybean Import Market: The U.S. Exporters vs. Japanese Importers

Genetically modified (GM) soybean acreage has rapidly increased in the world in the past decade and globally the majority of countries now use GM soybeans to produce oil and meal for livestock and human consumption. Japan, however, uses only Non-GM soybeans as widely recognized high quality goods in vertically differentiated import soybeans in Japan, for direct human consumption of which more than 80% are imported from the U.S., Canada, and China. This research used the inverse residual demand model to estimate a U.S.-Japan partial equilibrium trade model to test the existence of market power in the Japanese Non-GM soybean import market. The U.S.-Japan partial equilibrium trade model incorporated the U.S. residual Non-GM soybean supply for Japan, the Japanese residual demand for U.S. Non-GM soybeans, and the equilibrium condition, where the U.S. residual Non-GM soybean supply equals the Japanese residual Non-GM soybean demand. Monthly data from January 2003 to December 2007 were used for the analysis. Empirical results indicated that U.S. Non-GM soybean exporters have stronger market power than Japanese Non-GM soybean importers. The results are different from other countries empirical studies and indicate that Japanese consumers are willing to pay higher prices for soybeans, tofu, natto, miso, and other all soy food products using Non-GM soybeans