A Note on T-dualities in the Pure Spinor Heterotic String

In this note we study the preservation of the classical pure spinor BRST constraints under super T-duality transformations. We also determine the invariance of the one-loop conformal invariance and of the local gauge and Lorentz anomalies under the super T-dualities.Comment: References adde

Relación de la escala de intensidad de Mercalli y la información instrumental como una tarea de clasificación de patrones

A pesar de los progresos ocurridos en la instrumentación sísmica, la valoración de vulnerabilidad sísmica y el daño con índices cualitativos, tal como los proporcionados por Intensidad de Mercalli Modificada (IMM), siguen siendo altamente favorables y útiles para los propósitos prácticos. Para vincular las medidas cualitativas de acción del terremoto y sus efectos, es habitualmente aplicada la regresión estadística. En este artículo, se adopta un planteamiento diferente, el cual consiste en expresar la Intensidad de Mercalli, como una clase en vez de un valor numérico. Una herramienta de clasificación estadística moderna, conocida como máquina de vectores de soporte, se usa para clasificar la información instrumental con el fin de evaluar la intensidad de Mercalli correspondiente. Se muestra que el método da resultados satisfactorios con respecto a las altas incertidumbres y a la medida del daño sísmico cualitativo

Phase diagram of silicon from atomistic simulations

In this letter we present a calculation of the temperature-pressure phase diagram of Si in a range of pressures covering from -5 to 20 GPa and temperatures up to the melting point. The phase boundaries and triple points between the diamond, liquid, $\beta$-Sn and ${Si}_{34}$ clathrate phases are reported. We have employed efficient simulation techniques to calculate free energies and to numerically integrate the Clausius-Clapeyron equation, combined with a tight binding model capable of an accuracy comparable to that of first-principles methods. The resulting phase diagram agrees well with the available experimental data.Comment: 5 pages, 1 figure, accepted in PR

¿Cuáles son las respuestas de los periodistas de Ecuador tras la implementación de la Ley Orgánica de Comunicación? Una entrevista a periodistas de medios nacionales públicos y privados

With the Organic Communication Act, passed in 2013, the Government of Ecuador proposed to transform the media system by creating innovative institutions for monitoring and surveillance tasks, instituting a lot of precepts aiming at a greater inclusion of minority groups, favoring a greater diversity, and in general, to democratize the access, development and spreading of informative contents. This work provides the results from an in-depth interview to Ecuadorian journalists working for both public and private national media. The results describe some key aspects to understand the effects of the said Act regarding the journalists, which includes the perceived pressure factors, the strategies they rely on to resist the impositions, or how they interact with the new control institutions. © 2019 Pontificia Universidad Javeriana. All rights reserved

Special issue: Innovations in farming systems approaches: Introduction

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Primer reporte del género Cryptocheiridium (pseudoscorpiones: cheiridiidae: cheiridiinae) en Colombia

The pseudoscorpion genus Cryptocheiridium Chamberlin, 1931 is reported for the first time in Colombia, is described as new species Cryptocheiridium mairae sp. nov., in northwestern Colombia, associated with debris produced by the leafcutter ant Atta colombica Guérin-Méneville, 1844.El género de pseudoescorpion Cryptocheiridium Chamberlin, 1931 es reportado por primera vez en Colombia, es descrita como nueva especie Cryptocheiridium mairae sp. nov., del noroccidente colombiano, asociada a detritos de hormigas Atta colombica Guérin-Méneville, 1844

Voces de mujeres y mujeres diversas en la Biblioteca Pública La Victoria

In Public Libraries, the memory of the women-in particular diverse women-is a vital element to the collective construction of the localidentity. There for, women voices are a very important historical element in the time of the change, especially in this moment when the country is building a peace process. That is why, orality is the symbol of the liberty, equality and autonomy; thus, the library is a meeting place and a rights scenario, because the people to the fourth location of Bogotá (San Cristóbal), need to build speeches from the women and diverse women -victims or not of the violence-, and to use the knowledge in a social perspective of transformation. This is the point from The Public Library La Victoria and other social actors, (for instance District Women's Secretariat and Collective Archipiélago), are together in a work plan, trying to change the reality of the women and the diverse women in the territory; thorough reading, writing, culture, exchange of knowledge, debates and other participation mechanisms from the library as such. This experience show the work that library had done since 2015, in order to get that women and thediverse women empower themselves, using their voice to build local memory

C60-based hot-electron magnetic tunnel transistor

A C 60-based magnetic tunnel transistor is presented. The device is based on the collection of spin-filtered hot-electrons at a metal/C 60 interface, and it allows an accurate measurement of the energy level alignment at such interface. A 89% change in the collected current under the application of a magnetic field demonstrates that these devices can be used as sensitive magnetic field sensors compatible with soft electronics.Fil: Gobbi, M.. No especifíca;Fil: Bedoya Pinto, A.. No especifíca;Fil: Golmar, Federico. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Llopis, R.. No especifíca;Fil: Casanova, F.. No especifíca;Fil: Hueso, L. E.. No especifíca

The Role of Nitric Oxide in Stem Cell Biology

Nitric oxide (NO) is a gaseous biomolecule endogenously synthesized with an essential role in embryonic development and several physiological functions, such as regulating mitochondrial respiration and modulation of the immune response. The dual role of NO in embryonic stem cells (ESCs) has been previously reported, preserving pluripotency and cell survival or inducing differentiation with a dose-dependent pattern. In this line, high doses of NO have been used in vitro cultures to induce focused differentiation toward different cell lineages being a key molecule in the regenerative medicine field. Moreover, optimal conditions to promote pluripotency in vitro are essential for their use in advanced therapies. In this sense, the molecular mechanisms underlying stemness regulation by NO have been studied intensively over the current years. Recently, we have reported the role of low NO as a hypoxia-like inducer in pluripotent stem cells (PSCs), which supports using this molecule to maintain pluripotency under normoxic conditions. In this review, we stress the role of NO levels on stem cells (SCs) fate as a new approach for potential cell therapy strategies. Furthermore, we highlight the recent uses of NO in regenerative medicine due to their properties regulating SCs biology