Indirect Searches for Decaying Dark Matter

Numerous observations point towards the existence of an unknown elementary particle with no electromagnetic interactions, a large population of which was presumably produced in the early stages of the history of the Universe. This so-called dark matter has survived until the present day, accounting for the 26% of the present energy budget of the Universe. It remains an open question whether the particles comprising the dark matter are absolutely stable or whether they have a finite but very long lifetime, which is a possibility since there is no known general principle guaranteeing perfect stability. In this article we review the observational limits on the lifetime of dark matter particles with mass in the GeV-TeV range using observations of the cosmic fluxes of antimatter, gamma-rays and neutrinos. We also examine some theoretically motivated scenarios that provide decaying dark matter candidates.Comment: 47 pages, 11 figures, 6 tables. Invited review for the International Journal of Modern Physics A. Matches published versio

The Mexican Health Care System: Moving Toward Managed Care

No abstract available

Realidad, concepciones y tareas económicas: Notas sueltas

La única constante de la posguerra es la del cambio; cambio que se intensifica notoriamente desde comienzos de la década de los ochenta y que abarca todos los órdenes de la vida social: las economías se alteran estructuralmente y en sus interrelaciones, se transforman los sistemas políticos, las metamorfosis en las relaciones económicas internacionales no tienen paralelo en décadas. Hasta la década de los sesenta se pensaba que los países industrializados habían encontrado una senda estable de progreso por donde podrían avanzar con seguridad, sin mudanzas importantes en el modo de concebir al mundo y sus problemas, si se exceptúa el desafío planteado por el bloque socialista. Mayores conmociones habrían de sufrir las naciones en desarrollo, pero en cualquier caso la brecha del atraso se resolvería a imagen y semejanza de las historias del Norte industrializado. En ese tiempo, realidad y concepciones económicas dominantes caminan de la mano. Entre los años cuarenta y los sesenta la economía internacional, y en particular América Latina, experimenta el periodo más prolongado de auge del que se tenga memoria. Empleo pleno o desarrollo avanzan armónicamente con el Estado benefactor y el afianzamiento de los valores democráticos en el mundo occidental. Ese universo con un presente ordenado y un futuro predecible se ha desvanecido. No es que las necesidades de transformación de las zonas atrasadas hayan desaparecido, sino que se plantean revoluciones de magnitud semejante en el Norte industrializado y se alteran las bases mismas de las relaciones económicas y de poder entre las naciones.

La Ciudad de México y su nueva Constitución en el entorno nacional

ResumenFactores demográficos, sociales, económicos y políticos se suman para explicar la decadencia de la Ciudad de México como centro propulsor del desarrollo nacional. Entre 1970 y 2014, el Distrito Federal se ha reducido de 28 a 16% en su contribución al total del país. La contracción en su participación manufacturera ha sido todavía mayor de 32 a 7% en los mismos años. Mejores resultados y éxitos se han logrado en materia de política social y de apertura democrática por parte de iniciativas del gobierno local. Visto a futuro, la Ciudad de México requiere renovar su papel como cerebro del desarrollo nacional, a la par de encontrar vocaciones productivas que remocen su capacidad de multiplicar ingresos y empleo, sustentadas en la absorción y difusión de tecnologías avanzadas. En tales tareas, la nueva Constitución puede fungir como acicate indispensable, siempre que se plasme en programas y políticas industriales conjuntas del gobierno local, la Federación y los estados vecinos.AbstractDemographic, social, economic and political factors are added to explain the decline of the city of Mexico as the propeller Center of national development. Between 1970 and 2014, the Federal District has been reduced from 28 to 16% in its contribution to the total of the country. The contraction in its manufacturing participation has been still major from 32 to 7% in the same years. Better results and successes have been achieved as for social politics and democratic opening on the part of initiatives of the local government. Seen in the future, the City of Mexico requires renew its role as a brain of national development, at the same time find productive vocations that renew their ability to increase income and employment, based on the absorption and diffusion of advanced technologies. In such tasks, the new Constitution can serve as indispensable incentive, provided that it is translated into programs and joint industrial policies of the local government, the Federation and neighboring States

Characteristics of the Teacher-Students’ Oral Interaction Process in the First Level Class at the English Language Institute In The Light Of the Notion of Communicative Competence

Language teaching and learning in a classroom setting demands from the teacher a varied set of skills and knowledge to develop the wanted language competences in his/her students. This fact makes research in communicative competence very useful in order to improve methods and strategies. For this reason, in this paper the researcher gives response to the question: “What are the characteristics of the teacher-students’ oral interaction process in the first level class at the English Language Institute in the light of the notion of Communicative Competence?”. This descriptive ethnography took place in a small class of five adult students in elementary level who study English as a foreign language. Data collection is made through observation, and materials collection. The analysis is carried out from the perspective of four different theorists. After contrasting theory with data, organizational competence was proved to be the main competence developed in this classroom setting. This work is useful for all who want to do research on communicative competence, and those who are using class transcriptions to analyze and explain the nature of oral interaction in first or second language classrooms.MaestríaMagister en la Enseñanza del Ingle

Improving early design stage timing modeling in multicore based real-time systems

This paper presents a modelling approach for the timing behavior of real-time embedded systems (RTES) in early design phases. The model focuses on multicore processors - accepted as the next computing platform for RTES - and in particular it predicts the contention tasks suffer in the access to multicore on-chip shared resources. The model presents the key properties of not requiring the application's source code or binary and having high-accuracy and low overhead. The former is of paramount importance in those common scenarios in which several software suppliers work in parallel implementing different applications for a system integrator, subject to different intellectual property (IP) constraints. Our model helps reducing the risk of exceeding the assigned budgets for each application in late design stages and its associated costs.This work has received funding from the European Space Agency under Project Reference AO=17722=13=NL=LvH, and has also been supported by the Spanish Ministry of Science and Innovation grant TIN2015-65316-P. Jaume Abella has been partially supported by the MINECO under Ramon y Cajal postdoctoral fellowship number RYC-2013-14717.Peer ReviewedPostprint (author's final draft

Método para el desarrollo de productos mediante la caracterización de las decisiones en la conceptualización del diseño

Documento de la tesis a texto completo.Se propone un modelo matemático para pronósticar y diagnósticar los tiempos de desarrollo en las etapas del diseño. Con base en una muestra de diseñadores, se les presentan unos retos de diseño y se mide experimentalmente su desempeño. Así se construye el modelo objeto de la tesis, proporcionando a la literatura quizás uno de los primeros esfuerzos para cuantificar los proceso de diseño.Consejo Nacional de Ciencia y Tecnología de México (CONACYT