Oligopoly in grain production and consumption: an empirical study on soybean international trade in China

What has been neglected in much of the existing studies of the influence of seasonal and regional characteristics of agriculture on the market power and national security. This paper constructs a multivariate equations model to investigate the monopoly power of seasonal suppliers and national security in China’s soybean market. The results show no relationship between market share and monopoly power; and that CR3 and HHI show China’s soybean import market has been the highest oligopoly type, but the model suggest that exporters (the U.S., Brazil and Argentina) have very weak monopoly power and China has no monopsony power; and that the performance of some exporters’ soybeans is affected by others, while others are relatively independent in market. This is due to the non-substitutability of the product, the non-substitutability of the buyer and the seller, etc., which causes the mutual dependence of the seller and buyer, and their market power cancel each other out. The seasonality and regionality of soybean production is the root. Considering national security, it is necessary to take the seasonal and regional characteristics of exporters into account to disperse trade risks and oppose monopolisation of international food production and trad

Novel Method for Measuring Structure and Semantic Similarity of XML Documents Based on Extended Adjacency Matrix

AbstractSimilarity measurement of XML documents is crucial to meet various needs of approximate searches and document classifications in XML-oriented applications. Some methods have been proposed for this purpose. Nevertheless, few methods can be elegantly exploited to depict structure and semantic information and hence to effectively measure the similarity of XML documents. In this paper, we present a new method of computing the structure and semantic similarity of XML documents based on extended adjacency matrix(EAM). Different from a general adjacency matrix, in an EAM, the structure information of not only the adjacent layers but also the ancestor-descendant layers can be stored. For measuring the similarity of two XML documents, the proposed method firstly stores the structure and semantic information in two extended adjacency matrices(M1, M2). Then it computes similarity of the two documents through cos(M1, M2) Experimental results on bench-mark data show that the method holds high efficiency and accuracy

Multiconsensus of Second-Order Multiagent Systems with Input Delays

The multiconsensus problem of double-integrator dynamic multiagent systems has been investigated. Firstly, the dynamic multiconsensus, the static multiconsensus, and the periodic multiconsensus are considered as three cases of multiconsensus, respectively, in which the final multiconsensus convergence states are established by using matrix analysis. Secondly, as for the multiagent system with input delays, the maximal allowable upper bound of the delays is obtained by employing Hopf bifurcation of delayed networks theory. Finally, simulation results are presented to verify the theoretical analysis

Design Methodology for Six-Port Equal/Unequal Quadrature and Rat-Race Couplers With Balanced and Unbalanced Ports Terminated by Arbitrary Resistances

For the first time, the 6-port quadrature and rat-race couplers with balanced-unbalanced-hybrid ports are proposed. The corresponding design methodology is presented, which is capable of designing the proposed couplers with arbitrary power divisions and terminated resistances. In this paper, four types including quadrature and rat-race couplers are fully analyzed, covering all the application configurations of the balanced/unbalanced ports. Besides, the design equations are rigorously derived, with the final design procedures presented. Eventually, prototypes of the four coupler types are fabricated and experimentally measured. The final results sufficiently validate the proposed methodology

The small heat shock protein (sHSP) genes in the silkworm, Bombyx mori, and comparative analysis with other insect sHSP genes

<p>Abstract</p> <p>Background</p> <p>Small heat shock proteins (sHSPs) are products of heat shock response and of other stress responses, and ubiquitous in all three domains of life, archaea, bacteria, and eukarya. They mainly function as molecular chaperones to protect proteins from being denatured in extreme conditions. Study on insect sHSPs could provide some insights into evolution of insects that have adapted to diverse niches in the world.</p> <p>Results</p> <p>Taking advantage of the newly assembled genome sequence, we performed a genome-wide analysis of the candidate sHSP genes in the silkworm, <it>Bombyx mori</it>. Based on known silkworm sHSP sequences, we identified 16 silkworm sHSP genes. Most of them are distributed on two silkworm chromosomes 5 and 27, respectively. 15 of 16 silkworm sHSPs have expression evidence. The comparative analysis of insect sHSPs from <it>B. mori</it>, <it>Drosophila melanogaster</it>, <it>Apis mellifera</it>, <it>Tribolium castaneum</it>, and <it>Anopheles gambiae </it>revealed that there is only one orthologous cluster whereas remaining clusters are species-specific on the phylogenetic tree. This suggested that most of sHSPs might have diverged in function across insects investigated. In addition, the data presented in this study also revealed that sHSPs in the insect orthologous cluster are highly conserved in both sequence and expression pattern. In sum, insect sHSPs show a completely different evolutionary pattern from that found in vertebrate sHSPs.</p> <p>Conclusion</p> <p><it>B. mori </it>has the largest number of insect sHSP genes characterized to date, including 16 genes. The inference that most species-specific sHSPs might have diverged in function across insects investigated will help us understand the adaptability of these insects to diverse environments.</p

Ethyl 6-methyl-3-(2-methyl­prop-1-en­yl)-2-oxo-4-phenyl-1,2,3,4-tetra­hydro­pyrimidine-5-carboxyl­ate

In the mol­ecule of the title compound, C18H22N2O3, the dihydro­pyrimidinone ring adopts an envelope conformation. The dihedral angle between the phenyl ring and the mean plane through the enamine fragment is 86.04 (7)°. The mol­ecular conformation is stabilized by an intra­molecular C—H⋯O hydrogen bond. In the crystal, inter­molecular N—H⋯O hydrogen bonds link pairs of mol­ecules into centrosymmetric dimers

Twenty-six circulating antigens and two novel diagnostic candidate molecules identified in the serum of canines with experimental acute toxoplasmosis

List of CAg proteins identified by LC-MS/MS after IP enrichment and purification with ESA antibodies. (XLSX 27 kb