C lculo de p¢rticos de varios pisos

Proceedings of a symposium jointly organized by the IAEA and FAO, Vienna, 17-21 October 1994. The objective of the symposium was to assess the progress being made in the use of nuclear and related techniques for studying various aspects of soil fertility and plant nutrition, environmental problems, the potential and limitations of existing methods, and the possibilities for further development. Analytical methods and equipment are discussed, as are isotope dilution techniques, transfers of fixed N to non-fixing crops, crop water consumption, labelled fertilizer involving fertigation, 13C...

El día 2 de mayo del 2011 un comando de la marina de los Estados Unidos dio muerte en su refugio de Pakistán al enemigo público más buscado: Osama bin Laden. En este breve y ágil ensayo, Juan Avilés sostiene que ello representa el simbólico final de una década caracterizada por la obsesión ante la amenaza del terrorismo internacional. Es, pues, el momento apropiado para responder a los interrogantes que suscita la historia de Al Qaeda: acerca de sus orígenes, que se hallan en la doctrina del salafismo yihadí; de su fundación, vinculada a la guerra de Afganistán contra los...

The final formal report of the fourth session of the Commission for Inland Fisheries of Latin America, held in Havana, Cuba, from 20-25 January 1986, is presented. Major topics discussed during the session refer to: (1) progress achieved during the intersessional period, (2) fishery resources in lakes and rivers; (3) activities of the Regional Latin American Aquaculture Centre; (4) fishing gears and methods for artisanal fisheries in continental waters; (5) fish utilization and marketing, and (6) follow-up to the FAO World Conference on Fisheries Management and Development. A minisymposium on ...

"An urgent and expert investigation into behavioral addiction, the dark flipside of today's unavoidable digital technologies, and how we can turn the tide to regain control. Behavioral addiction may prove to be one of the most important fields of social, medical, and psychological research in our lifetime. The idea that behaviors can be being addictive is new, but the threat is near universal. Experts are just beginning to acknowledge that we are all potential addicts. Adam Alter, a professor of psychology and marketing at NYU, is at the cutting edge of research into what makes these products ...