510 research outputs found
Mind the Gap!
In his review of Protocells, Antonio Lazcano explores how the self-assemblage properties of lipids into bilayers, micelles, and liposomes can be used to model minimal cells, design biochemical microreactors, and provide insights into the predecessors of the first living beings
The RNA World : piecing together the historical development of a hypothesis
The concept of an RNA world is a hypothesis firmly rooted in empirical data and is part of a long and complex scientific perspective that goes back more than fifty years to the discovery of the central role RNA and ribonucleotides play in protein synthesis and biochemical reactions took place. As the understanding of RNA biology progressed, several independent proposals of protein-free primordial life forms were suggested. Although this possibility was strongly reinforced with the discovery of ribozymes, there are many definitions of the RNA world, including several contradictory ones. One could say that it was an early, perhaps primordial, stage during which RNA molecules played a much more conspicuous role in heredity and metabolism and, particularly, in the origin and early evolution of protein biosynthesis. The overwhelming evidence for the catalytic, regulatory, and structural properties of RNA molecules, combined with their ubiquity in cellular processes, can only be explained with the proposal that they played a key role in early evolution and perhaps in the origin of life itself
The young Ramón y Cajal as a cell-theory dissenter
Pereto Magraner, Juli, [email protected]
EL CENTRALIDAD COMO UN ARQUETIPO SOCIAL DE LA CIUDAD
La centralidad ligada al crecimiento de las ciudades se traduce en un arquetipo social y urbano. En su origen los centros contribuyeron de manera significativa al desarrollo de la vida comunitaria. Los grandes imperios convirtieron a la centralidad en un mecanismo de control y sometimiento social. Una excesiva centralidad producirá tarde o temprano una severa crisis sistémica. El reto de la nueva centralidad radica en recuperar el sentido democrático de los núcleos urbanos.La centralidad ligada al crecimiento de las ciudades se traduce en un arquetipo social y urbano. En su origen los centros contribuyeron de manera significativa al desarrollo de la vida comunitaria. Los grandes imperios convirtieron a la centralidad en un mecanismo de control y sometimiento social. Una excesiva centralidad producirá tarde o temprano una severa crisis sistémica. El reto de la nueva centralidad radica en recuperar el sentido democrático de los núcleos urbanos
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