The Universidad Nacional Autónoma de México is a public research university in Mexico City, Mexico that is the largest university in Latin America. UNAM was founded, in its modern form, on 22 September 1910 by Justo Sierra as a liberal alternative to its preceding institution the Royal and Pontifical University of Mexico . To this date, the National Autonomous University of Mexico owns and uses for academic activities the old buildings located in downtown Mexico City that once belonged to the old Royal and Pontifical University of Mexico UNAM's autonomy, granted in 1929, has given it the freedom to define its own curriculum and manage its own budget without interference from the government. This has had a profound effect on academic life at the university, which some claim boosts academic freedom and independence.The UNAM generates a number of different publications in diverse areas, such as mathematics, physics and history. It is also the only university in Mexico with Nobel Prize laureates among its alumni: Alfonso García Robles , Octavio Paz , and Mario Molina .Besides being the most recognized university in Latin America, its campus is one of the largest and most artistically detailed. It is a World Heritage site that was designed by some of Mexico's best-known architects of the 20th century. Murals in the main campus were painted by some of the most recognized artists in Mexican history such as Diego Rivera and David Alfaro Siqueiros. The UNAM is widely regarded by many university world rankings as the leading university of the Spanish-speaking world. Wikipedia.
Briscese F.,National Autonomous University of Mexico
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics | Year: 2011
We study the viability of a complex scalar field χ with self-interacting potential V=m0 χ/2|χ|2+h|χ|4 as dark matter. The scalar field is produced at reheating through the decay of the inflaton field and then, due to the self-interaction, a Bose-Einstein condensate of χ particles forms. The condensate represents dark matter in that model. We analyze the cosmological evolution of the model, stressing how, due to the presence of the self-interaction, the model naturally admits dark matter domination at late times, thus avoiding any fine tuning on the energy density of the scalar field at early times. Finally we give a lower bound for the size of dark matter halos at present time and we show that our model is compatible with dark matter halos greater than 0.1 kpc and with BBN and CMB bounds on the effective number of extra neutrinos Δν eff. Therefore, the model is viable and for hb≃10-4-10-12 one obtains a mass mχb≃m0χb≃1-10-2 eV for dark matter particles from radiation-matter equality epoch to present time, but at temperatures Tγ≫10 eV, where Tγ is the photons temperature, thermal corrections to m0 χ due to the self-coupling h are dominant. © 2011 Elsevier B.V.
Vega G.,National Autonomous University of Mexico
IEEE Transactions on Information Theory | Year: 2012
The weight distribution of a class of nonirreducible cyclic codes was given by Ma . By imposing a special set of conditions on this class of codes, it was recently shown that the resulting codes, for this class, can be obtained as elements in a family of codes introduced by Vega in . Now, by using a different set of conditions, the aim of this paper is to present an extended version for the class of codes studied by Ma © 2012 IEEE.
Selman M.,Instituto Nacional Of Enfermedades Respiratorias Ismael Cosio Villegas |
Pardo A.,National Autonomous University of Mexico
American Journal of Respiratory and Critical Care Medicine | Year: 2014
A growing body of evidence indicates that aberrant activation of alveolar epithelial cells and fibroblasts in an aging lung plays a critical role in the pathogenesis of idiopathic pulmonary fibrosis (IPF). However, the biopathological processes linking aging with IPF and the mechanisms responsible for the abnormal activation of epithelial cells and fibroblasts have not been elucidated. Many of the hallmarks of aging (e.g., genomic instability, telomere attrition, epigenetic alterations, mitochondrial dysfunction, and cellular senescence) have been proposed as essential mechanisms for the development of IPF; however, these disturbances are not restricted to IPF and also occur in other aging-related lung disorders, primarily chronic obstructive pulmonary disease (COPD). Therefore, an unanswered question is why a current/former smoker of about 60 years of age with shorter telomeres, alveolar epithelial senescence, excessive oxidative stress, and mitochondrial dysfunction develops IPF and not COPD; in other words, what makes old lungs specifically susceptible to develop IPF? In this Perspective, we propose an integral model in which the combination of some gene variants and/or gene expression in the aging lung results in the loss of epithelial integrity and consequently in the failure of the alveoli to correctly respond to injury and to face the stress associated with mechanical stretch. Afterward, a distinctive epigenetic "reprogramming" that affects both epithelial cells and fibroblasts provokes, among others, the recapitulation of developmental pathways and the aberrant activation and miscommunication between both cell types, resulting in the exaggerated production and accumulation of extracellular matrix and the subsequent destruction of the lung architecture. Copyright © 2014 by the American Thoracic Society.
Fornoni J.,National Autonomous University of Mexico
Functional Ecology | Year: 2011
1. Plant tolerance to herbivory has been accepted as a mechanism of defense that can be expressed jointly with resistance. Recent advances have partially validated previous theoretical predictions and improved our understanding of tolerance. Here, I highlight the necessity of integrating tolerance into ecological and co-evolutionary theory to better understand the biology of this defensive mechanism. 2.Existing work has been biased toward understanding the adaptive nature and constraints acting on tolerance rather than its ecological implications. Increasing consensus that tolerance may alter the classical antagonistic dynamic between plants and herbivores suggests possible avenues to explore its population and community consequences. 3.In this review, I summarize previous advances in the ecology and evolution of tolerance to herbivory. I also discuss recent evidence that improves our understanding of unresolved issues such as the specificity of tolerance in response to herbivory, its role as an agent of selection on herbivores, and its ecological and evolutionary consequences which include a role of tolerance during biological invasions. 4.Although there is good support for an adaptive role of tolerance in response to herbivory damage, tolerance can itself impose selection on herbivores. Furthermore, tolerance can influence herbivore population dynamics and coexistence, as recent studies show that tolerance responses increase diversity of the associated herbivore communities on individual host plants. 5.Future studies that take into account the role of herbivores on the expression of tolerance will provide novel insight that will help disentangle the mechanisms of tolerance and its ecological and evolutionary implications. © 2010 The Author. Functional Ecology © 2010 British Ecological Society.
Manzanilla L.R.,National Autonomous University of Mexico
Proceedings of the National Academy of Sciences of the United States of America | Year: 2015
In this paper, I address the case of a corporate society in Central Mexico. After volcanic eruptions triggered population displacements in the southern Basin of Mexico during the first and fourth centuries A.D., Teotihuacan became a multiethnic settlement. Groups from different backgrounds settled primarily on the periphery of the metropolis; nevertheless, around the core, intermediate elites actively fostered the movement of sumptuary goods and the arrival of workers from diverse homelands for a range of specialized tasks. Some of these skilled craftsmen acquired status and perhaps economic power as a result of the dynamic competition among neighborhoods to display the most lavish sumptuary goods, as well as to manufacture specific symbols of identity that distinguished one neighborhood from another, such as elaborate garments and headdresses. Cotton attire worn by the Teotihuacan elite may have been one of the goods that granted economic importance to neighborhood centers such as Teopancazco, a compound that displayed strong ties to the Gulf Coast where cotton cloth was made. The ruling elite controlled raw materials that came from afar whereas the intermediate elite may have been more active in providing other sumptuary goods: pigments, cosmetics, slate, greenstone, travertine, and foreign pottery. The contrast between the corporate organization at the base and top of Teotihuacan society and the exclusionary organization of the neighborhoods headed by the highly competitive intermediate elite introduced tensions that set the stage for Teotihuacan's collapse.