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Several investigations have shown that the mathematics textbook continues to be the main work tool for teachers and, among other things, constitutes the referent of school mathematical knowledge that they must teach to students. However, it has also been manifested that the texts can be a source of conflicts in both students and teachers, due to the treatment they give to mathematical notions. In this article we have been interested in how textbooks develop the study of algebra in primary education and, in particular, if these ways of presenting algebraic notions could cause conflicts. To carry out our study, we used some theoretical-methodological tools of the Ontosemiotic Approach (OSA) of mathematical knowledge and instruction, such as the notion of conflict and the ontosemiotic configuration, which allowed a systematic analysis of the mathematics textbooks in terms of the problems, definition of concepts, properties, procedures, arguments and representations. As a main result, categories of potential conflicts for the study of algebra are identified and discussed, which could lead to errors or misconceptions of algebraic notions by students or teachers., Diversas investigaciones han evidenciado que el libro de texto de matemáticas sigue siendo la principal herramienta de trabajo para los profesores y, entre otras cosas, constituye el referente del conocimiento matemático escolar que deben enseñar a los estudiantes. Sin embargo, también se ha puesto de manifiesto que los textos pueden ser fuente de conflictos tanto en estudiantes como en profesores, debido al tratamiento que dan a los conceptos matemáticos. En este artículo nos hemos interesado por cómo los libros de texto desarrollan el estudio del álgebra en la educación básica y, en particular, si estas formas de presentar las nociones algebraicas pudieran causar conflictos. Para llevar a cabo nuestro estudio, utilizamos algunas herramientas teórico-metodológicas del Enfoque Ontosemiótico (EOS) del conocimiento y la instrucción matemáticos, tales como la noción de conflicto y la configuración ontosemiótica, lo cual permitió un análisis sistemático de los textos en términos de los problemas, definiciones de los conceptos, propiedades, procedimientos, argumentos y representaciones. Como resultado principal, se identifican y discuten categorías de conflictos potenciales para el estudio del álgebra, los cuales podrían inducir a errores o concepciones erróneas de las nociones algebraicas por parte de los estudiantes o profesores.

Over the next 20 years, China's gross domestic product and defense budget could exceed those of the United States, making it a true peer competitor. Despite this potential, China's security interests and military capabilities will remain focused on its immediate periphery. China does not appear interested in matching U.S. military expenditures, achieving a comparable global reach, or assuming defense commitments beyond its immediate sphere. As a result, armed conflict between the United States and China is unlikely. Key Points: (1) Even as China becomes a near peer competitor, armed conflict between China and the United States will be unlikely; (2) To ensure this, the United States must retain its deterrent capacity and bolster the capabilities and resolve of other regional states; (3) Should conflict with China occur, the economic consequences would be historically unparalleled; and (4) A collapse of the Democratic People's Republic of Korea is the most likely East Asia contingency, and U.S. ground forces will be essential to address it., This research brief describes work done by the RAND Arroyo Center and documented in Conflict with China: Prospects, Consequences, and Strategies for Deterrence, by James Dobbins, David C. Gompert, David A. Shlapak, and Andrew Scobell, OP-344-A, 2011.

In this paper we discuss various control loop patterns for managing distributed applications with multiple control loops. We introduce a high-level framework, called DCMS, for developing, deploying and managing component-based distributed applications in dynamic environments. The control loops, and interactions among them, are illustrated in the context of a distributed self-managing storage service implemented using DCMS to achieve various self-* properties. Different control loops are used for different self-* behaviours, which illustrates one way to divide application management, which makes for both ease of development and for better scalability and robustness when managers are distributed. As the multiple control loops are not completely independent, we demonstrate different patterns to deal with the interaction and potential conflict between multiple managers., QC 20110302