Hemeroteca del mes enero, 2014

Dualidades de América Latina (III): Rebeliones y Proyectos

Por • 31 ene, 2014 • Category: Economía

Al comienzo del nuevo siglo estallaron en Sudamérica grandes rebeliones sociales, que modificaron el escenario de reflujo popular en que se asienta el neoliberalismo. Estos levantamientos pusieron un límite a la ofensiva del capital y al proyecto que gestó la derecha para sepultar el ascenso revolucionario de los años 70. Los cuatro alzamientos victoriosos se localizaron en Argentina, Bolivia, Ecuador y Venezuela entre el 2000 y el 2005. Fueron rebeliones masivas en medio de grandes crisis políticas, que incluyeron vacío de poder, repliegue de fuerzas represivas, derrotas de la reacción y desconcierto de las clases dominantes. Los mandatarios identificados con el neoliberalismo fueron expulsados de la presidencia y los programas de virulenta privatización, apertura comercial y flexibilización laboral perdieron sostén social. Estas conmociones influyeron sobre otros países (Brasil, Uruguay, Paraguay, Colombia), que no registraron movilizaciones de esa envergadura. Estas acciones superaron ampliamente los estadios básicos de una protesta social, mejoraron las condiciones para obtener conquistas populares y propinaron derrotas a los dominadores. Estos resultados no se han registrado en otras partes del mundo.



How a New Science of Cities Is Emerging from Mobile Phone Data Analysis

Por • 30 ene, 2014 • Category: sociologia

Study the way people make mobile phone calls in metropolitan areas and you can see a city breathe, say computer scientists. Mobile phones have generated enormous insight into the human condition thanks largely to the study of the data they produce. Mobile phone companies record the time of each call, the caller and receiver ids, as well as the locations of the cell towers involved, among other things. The combined data from millions of people produces some fascinating new insights in the nature of our society. Today, computer scientists have gone one step further by using mobile phone data to map the structure of cities and how people use them throughout the day. “These results point towards the possibility of a new, quantitative classification of cities using high resolution spatio-temporal data,” say Thomas Louail at the Institut de Physique Théorique in Paris and a few pals.



(In)dependence Logic and Abstract Independence Relations

Por • 30 ene, 2014 • Category: Opinion

We generalize the results of [15] and [16] to the framework of abstract independence relations for an arbitrary AEC. We give a model-theoretic interpretation of the independence atom and characterize under which conditions we can prove a completeness result with respect to the deductive system that axiomatizes independence in team semantics.



A Friendly Intro to Sieves with a Look Towards Recent Progress on the Twin Primes Conjecture

Por • 30 ene, 2014 • Category: Educacion

This is an extension and background to a talk I gave on 9 October 2013 to the Brown Graduate Student Seminar, called `A friendly intro to sieves with a look towards recent progress on the twin primes conjecture.’ During the talk, I mention several sieves, some with a lot of detail and some with very little detail. I also discuss several results and built upon many sources. I’ll provide missing details and/or sources for additional reading here.



Category theory, logic and formal linguistics: some connections, old and new

Por • 30 ene, 2014 • Category: Crítica

We seize the opportunity of the publication of selected papers from the \emph{Logic, categories, semantics} workshop in the \emph{Journal of Applied Logic} to survey some current trends in logic, namely intuitionistic and linear type theories, that interweave categorical, geometrical and computational considerations. We thereafter present how these rich logical frameworks can model the way language conveys meaning.



Category Theory Using String Diagrams

Por • 30 ene, 2014 • Category: Ciencia y tecnología

In work of Fokkinga and Meertens a calculational approach to category theory is developed. The scheme has many merits, but sacrifices useful type information in the move to an equational style of reasoning. By contrast, traditional proofs by diagram pasting retain the vital type information, but poorly express the reasoning and development of categorical proofs. In order to combine the strengths of these two perspectives, we propose the use of string diagrams, common folklore in the category theory community, allowing us to retain the type information whilst pursuing a calculational form of proof. These graphical representations provide a topological perspective on categorical proofs, and silently handle functoriality and naturality conditions that require awkward bookkeeping in more traditional notation.



Is ergodicity a reasonable hypothesis?

Por • 30 ene, 2014 • Category: Leyes

In the physics literature “ergodicity” is taken to mean that a system, including a macroscopic one, visits all microscopic states in a relatively short time. We show that this is an impossibility even if that time is billions of years. We also suggest that this feature does not contradict most physical considerations since those considerations deal with correlations of only a few particles.



Atacar al Ministro Ramírez es el camino equivocado, sólo la rectificación salva

Por • 30 ene, 2014 • Category: Nacionales

Atacar al Ministro Ramírez es el camino equivocado.Hoy se impone rectificar errores!



Chevron orgullosa de poder ser socia de Pdvsa en la Faja del Orinoco

Por • 30 ene, 2014 • Category: Nacionales

Petropiar es el nombre de una de las dos empresas mixtas que asocia en la Faja a Chevron con PDVSA, la cual cuenta con un capital que se distribuye 70 %-30 % a favor de la estatal venezolana, y que extrae 158.000 barriles diarios en 507 pozos.



Delegación de Ecopetrol visitó la Faja Petrolífera del Orinoco

Por • 30 ene, 2014 • Category: Nacionales

Con una visita a los mejoradores y áreas de producción de las empresas mixtas PDVSA Petropiar y Petrocedeño, una delegación de alto nivel de la petrolera colombiana Ecopetrol inició una gira de tres días por las empresas mixtas de la Faja Petrolífera del Orinoco (FPO), para conocer la experiencia de Petróleos de Venezuela, S.A, (PDVSA) en cuanto a producción y mejoramiento de crudo proveniente de la reserva de extrapesados más grande del planeta.