Splitters and Decomposers for Binary Matroids

Let $EX[M_1\dots, M_k]$ denote the class of binary matroids with no minors isomorphic to $M_1, \dots, M_k$. In this paper we give a decomposition theorem for $EX[S_{10}, S_{10}^*]$, where $S_{10}$ is a certain 10-element rank-4 matroid. As corollaries we obtain decomposition theorems for the classes obtained by excluding the Kuratowski graphs $EX[M(K_{3,3}), M^*(K_{3,3}), M(K_5), M^*(K_5)]$ and $EX[M(K_{3,3}), M^*(K_{3,3})]$. These decomposition theorems imply results on internally $4$-connected matroids by Zhou [\ref{Zhou2004}], Qin and Zhou [\ref{Qin2004}], and Mayhew, Royle and Whitte [\ref{Mayhewsubmitted}].Comment: arXiv admin note: text overlap with arXiv:1403.775

Doubts and Puzzles: Young Galeano Writing about New China during the Sino-Soviet Split

As a journalist of Uruguay’s Marcha weekly newspaper, Eduardo Galeano visited China in September 1963; he was warmly received by Chinese leaders including Premier Zhou Enlai. At first, Galeano published some experiences of his China visit in Marcha. In 1964, he published the complete journal of the trip, under the title of China, 1964: crónica de un desaf í o [“China 1964: Chronicle of a Challenge”]. Based on Chinese-language materials, this paper explores Galeano’s trip to China at that time and includes a close reading of Galeano’s travel notes. By analyzing his views on the New China, Socialism, and the Sino-Soviet Split, we will try to determine whether this China visit influenced his world view and cultural concepts. Como periodista del semanario uruguayo Marcha, Eduardo Galeano visitó China en septiembre de 1963 donde fue calurosamente recibido por los líderes chinos, incluido el Primer Ministro Zhou Enlai. Al principio, Galeano publicó algunas experiencias de su visita a China en Marcha. En 1964, publicó el diario completo del viaje bajo el título China, 1964: crónica de un desafío. Basado en materiales en chino, este artículo explora el viaje de Galeano e incluye una lectura detallada de sus notas. Por medio de un análisis de sus puntos de vista sobre la Nueva China, el socialismo y la ruptura sinosoviética, se intenta determinar si esta visita a China influyó en su visión del mundo y en sus conceptos culturales

Universally Kuratowski-Ulam spaces and open-open games

We examine the class of spaces in which the second player has a winning strategy in the open--open game. We show that this spaces are not universally Kuratowski-Ulam. We also show that the games G and G7 introduced by P. Daniels, K. Kunen, H. Zhou [Fund. Math. 145 (1994), no. 3, 205--220] are not equivalent

Commercial Revitalization in Low-Income Urban Communities: General Tax Incentives vs. Direct Incentives to Developers

This paper proposes a commercial development model, based on Fujita's (1988) monopolistic competition model of spatial agglomeration, to examine stores' decisions to enter urban communities. The model focuses on commercial developers and large stores, and identifies a potential holdup problem in the commercial development market arising because developers incur costs before negotiating with anchor tenants over pro fit sharing; the holdup problem is more likely to occur in low-income communities where the profitability of commercial projects is small. The model predicts that direct incentives to developers are preferred to general tax incentives for addressing this market failure.urban redevelopment programs; economic agglomeration; holdup problem